Citrus Heights Municipal Code Div. 2 Private Wells and Pumps

(a) Purpose. It is the purpose of this division to protect the health, safety, and general welfare of the people of the city by ensuring that the groundwater of this city will not be polluted or contaminated by improper well construction, modification, repair, inactivation, or destruction, or by improper pump installation. To this end, minimum requirements are contained in this division for construction, modification, repair, inactivation, and destruction of wells and for installation of pumps.

(b) Words defined in other documents. Except as otherwise required by the context of this division, the terms used in this division shall have the same meaning as in Water Code § 13700 et seq. and the department of water resources bulletin 74-81 and subsequent supplements or revisions.

(c) Individual wells required. When individual water wells are the proposed domestic water supply, each lot or parcel shall have its own individually drilled well located on the subject lot or parcel. This shall not apply to lots or parcels served by an approved public water system.

(Ord. No. 97-01, § 2(6.28.000), 1-2-1997; Ord. No. 97-13, § 2, 3-26-1997; Ord. No. 97-17, § 2, 9-24-1997)

The following words, terms and phrases, when used in this division, shall have the meanings ascribed to them in this section, except where the context clearly indicates a different meaning:

Applicant means:

(1) The legal owner of the property on which the pump is to be installed or repaired or on which the well is to be constructed, modified or repaired, inactivated or destroyed;

(2) A licensed contractor who shall perform the work on the well or pump; or

(3) The owner's or contractor's agent authorized in writing to make an application on behalf of the principal.

Board means the county board of supervisors.

Construction means digging, boring, drilling, casing, perforating, screening, gravel packing, and sealing of wells, or installing of a well pump, in accordance with all standards adopted by this division.

Contamination and pollution have the meanings ascribed to them by Water Code § 13050.

Deputy means the community development director.

Destruction of wells means the proper decommissioning of wells to ensure that the groundwater supply is protected and preserved for future use and to eliminate potential physical hazards, in accordance with all standards adopted by this division.

Emergency means a stoppage, interruption, or significant reduction of water supply to domestic, industrial, or agricultural uses.

Enforcement agency means the community development department.

(1) The community development department, hazardous materials division, shall be responsible for the enforcement of this division as it pertains to the following:

a. All wells constructed for the purposes of detecting, monitoring or extracting hazardous materials in the vadose zone or in groundwater, except those wells which are constructed to comply with landfill monitoring and/or mitigation requirements; and

b. All wells constructed for the purpose of cathodic protection of underground storage tanks containing hazardous materials.

(2) The community development department, environmental health division, shall be responsible for the enforcement of this division as it pertains to all other wells defined by this division.

Modification and repair mean the deepening, reperforation, sleeving, sealing, or replacement of a well casing; or the repair or replacement of a well pump.

Nuisance means anything which meets all of the following requirements:

(1) Is injurious to health, or is indecent or offensive to the senses, or an obstruction to the free use of property, so as to interfere with the comfortable enjoyment of life or property.

(2) Affects at the same time an entire community or neighborhood, or any considerable number of persons, although the extent of the annoyance or damage inflicted upon individuals may be unequal.

(3) Occurs during, or as a result of, the treatment or disposal of wastes.

Permit means a printed document, issued by the enforcement agency, which permits the construction, modification, repair, inactivation, or destruction of a well; or the installation, repair, or replacement of a well pump.

Person means any individual, trust, firm, joint stock company, corporation, partnership or association. The term "person" also includes any city, county, district, the state, the federal government or any agency thereof to the extent that such persons may lawfully be regulated under this division.

Water table means the top of the saturated zone where unconfined groundwater is under atmospheric pressure.

Well and water well mean any artificial excavation constructed by any method for the purpose of extracting water from, or injecting water into, the underground. In addition, for purposes of this division, the following structures are also defined as wells: abandoned wells, agricultural wells, air conditioning wells, cathodic protection wells, community domestic wells, exploratory holes (borings), extraction wells, horizontal wells, inactive wells, individual domestic wells, industrial wells, injection wells, monitoring wells, test wells, vapor extraction wells, and water supply wells. It is not intended that potholes, drainage trenches or canals, wastewater ponds, shallow root zone piezometers, stock ponds, leaching pits, or similar excavations be included within the definition of a well.

(1) Abandoned well means any well that has not been used for a period of one year, unless the owner demonstrates intention to use the well again, by obtaining an inactivation permit.

(2) Agricultural well means any well used to supply water only for irrigation or other agricultural purposes.

(3) Air conditioning well means any well constructed to return to the groundwater which has been used as a coolant in air conditioning processes.

(4) Cathodic protection well means any artificial excavation in excess of 50 feet constructed by any means for the purpose of installing equipment or facilities for the protection electrically of metallic equipment in contact with the ground, commonly referred to as "cathodic protection."

(5) Community domestic well means any water well used to supply water for domestic purposes to a public water system as defined by the Health and Safety Code § 4010. Such wells are variously referred to as "municipal wells," "city wells," "public water supply wells" or "small water system wells."

(6) Exploratory hole (boring) means an uncased temporary excavation or boring drilled to a depth within ten feet of groundwater, or deeper, based on available groundwater data, the purpose of which is the immediate determination of hydrologic or geologic conditions at a site.

(7) Extraction well means an artificial excavation constructed by any method for the purpose of removing groundwater to be used either for permanent dewatering or for removal of groundwater for cleanup of contamination.

(8) Horizontal well means a well drilled horizontally or at an angle different from vertical.

(9) Inactive well means any well that is not routinely operated, but is intended to be reused in the future, and is capable of being made operable with a minimum of effort, and is not a nuisance, and for which an inactivation permit has been obtained.

(10) Individual domestic well means any water well used to supply domestic water to one water connection, either residential or commercial, serving fewer than 25 persons.

(11) Industrial well means any water well used to supply industry on an individual basis, in contrast to supplies provided through community systems.

(12) Injection well means an artificial excavation constructed by any method for the purpose of introducing water, nutrient solutions, treated water, or reclaimed water into the underground as a means of replenishing groundwater basins, enhancing recovery of chemical constituents, or establishing hydraulic control over local groundwater.

(13) Monitoring well means any artificial excavation constructed by any method for the purpose of monitoring fluctuations in groundwater levels, quality of underground waters, or the concentration of contaminants in underground waters.

(14) Test well means a cased well constructed to obtain information needed for the design of other wells.

(15) Vapor extraction well means an artificial excavation constructed by any method for the purpose of injection, monitoring or extraction of vapors or liquids, or both, into or from the predominantly unsaturated zone above the water table.

(16) Water supply well means any well constructed for the purpose of water supply. This includes community and individual domestic wells and agricultural or industrial water wells as defined by state well standards or by this division.

(17) Exempt wells means the following wells, which are exempt from the requirements of this division:

a. Any well constructed under the jurisdiction of the state department of conservation, except any such well which is converted to a use regulated by this division;

b. Any well used for the purpose of dewatering excavations during construction or for stabilizing hillsides or earth embankments; or

c. Other wells the regulation of which is not necessary to fulfill the purpose of this division, as determined by the deputy, and approved by the county health officer.

(Ord. No. 97-01, § 2(6.28.010), 1-2-1997; Ord. No. 97-13, § 2, 3-26-1997; Ord. No. 97-17, § 2, 9-24-1997)

Cross reference— Definitions generally, § 1-2.

(a) It shall be unlawful for any person to construct, modify, repair, inactivate, or destroy any well or to install, repair, or replace any well pump unless such person has:

(1) Obtained a permit issued from the enforcement agency for the specific work to be performed; or

(2) In an emergency, fully complied with the sections of this division relating to emergencies.

(b) It shall be unlawful for any person to construct, modify, repair, inactivate, or destroy any well or to install, repair, or replace any well pump unless such action is in accordance with the standards set forth in this division.

(c) It shall be unlawful for the property owner to allow a nuisance or an abandoned well to exist on the property.

(d) It shall be unlawful for any person to willfully or intentionally submit any false statement, record, or data in connection with a permit application to construct, modify, repair, inactivate, or destroy a well or to repair or replace any well pump.

(Ord. No. 97-01, § 2(6.28.020), 1-2-1997; Ord. No. 97-13, § 2, 3-26-1997; Ord. No. 97-17, § 2, 9-24-1997)

(a) Required. No person shall dig, bore, drill, deepen, modify, repair, inactivate, or destroy a well or install, repair, or replace a well pump without first applying for and receiving a permit as provided in this division unless exempted by law. A separate permit and fee is required for each well or pump. Where removal of a well pump or breaking of the well seal is not necessary, a pump permit shall not be required. It is not intended that a permit be obtained for the installation of a temporary pump.

(1) Persons to whom permits issued. Permits shall be issued pursuant to this division only to the legal owner of the property on which the well is to be constructed, modified, repaired, or destroyed or on which the pump is to be installed or repaired; to a person holding a valid state C-57 contractor's license as described in this subsection; or to the owner's or driller's authorized representative. Permits for inactivation of wells shall be issued only to the legal owner of the property on which the wells are to be inactivated.

All construction, modification, repair, or destruction work on wells shall be performed by a person who possesses a valid C-57 contractor's license in accordance with Business and Professions Code § 7000 et seq. and Water Code § 13750.5. Installation, repair, or replacement of a well pump shall be performed by a person who possesses a valid C-57, C-61 or class A contractor's license. Such license shall be in effect and in good standing with the state contractors' licensing board.

In accordance with Labor Code § 3800, unless exempted by that section, the contractor performing the work must also file the following with the enforcement agency:

a. A certificate of consent to self-insure issued by the director of the state department of industrial relations;

b. A certificate of worker's compensation insurance issued by an admitted insurer; or

c. An exact copy or duplicate thereof certified by the director of the state department of industrial relations or the insurer.

The certificate of insurance shall state that there is in existence a valid policy of worker's compensation insurance in a form approved by the insurance commissioner. The certificate shall show the expiration date of the policy. No insurer shall issue such certificate unless the full deposit premium on the policy has been paid, and the insurer shall give the county at least ten days' advance notice of the cancellation of the policy.

(2) Late fee for failure to obtain permit. Any person who commences any work for which a permit is required by this division without having first obtained a permit shall be required to pay a late fee equal to twice the standard permit fee.

(3) Emergency work. This subsection shall not apply to emergency work required to maintain drinking, agricultural, or industrial water supply systems or to prevent an imminent and substantial threat to public health and safety. In such cases, the person responsible for the emergency work shall comply with the following:

a. Time limit. Apply for a permit within three working days after commencement of the emergency work.

b. Urgency. Satisfy the enforcement agency that such work was urgently necessary. If the cause for urgency is not satisfactorily shown, penalties as described in section 98-63 shall be imposed.

c. Conformance with standards. Demonstrate that all work was performed in conformance with the technical standards set forth in this division.

(b) Application procedure. Applications for permits shall be made to the enforcement agency and shall contain all such information the enforcement agency requires to accomplish the purposes of this division. This application shall be made in writing and signed by the applicant on such forms as may be prescribed by the enforcement agency. The application shall be accompanied by the required application fee.

(c) Application fees. Application fees adopted and modified by the city council shall accompany the permit application. For activities regulated in this division which occur at sites for which other cost recovery mechanisms are available, application fees may be deferred, at the approval of the enforcement agency, pending recovery of those costs incurred for oversight of such activities. The party responsible for payment of oversight costs incurred by the department shall be responsible for payment of application fees if such fees are unable to be recovered through the alternative cost recovery mechanism.

(d) Permit approval. If the enforcement agency finds that the permit application contains all the necessary information and the proposed work is in compliance with all applicable well standards as defined in this division, the enforcement agency shall issue the applicant a comprehensive permit containing such conditions as are necessary to fulfill the purposes of this division. The permit approval received from the enforcement agency is separate from any other permit or clearance that may be required by another governmental agency or entity.

(e) Permit conditions. Conditions may be placed on the permit as follows:

(1) Special conditions. When the enforcement agency issues a permit pursuant to this division, it may condition the permit in any manner necessary to carry out the purposes of this division. Conditions may include but are not limited to special construction requirements, special destruction requirements, greater setback distance requirements, greater grout seal thickness, greater annular space, special wellhead construction, or demonstration of adequate water quantity or quality or both, after well completion.

(2) Proper disposal of drilling fluids and soil cuttings. The applicant is required to see that safe and appropriate measures are taken in the handling and disposal of drilling fluids, soil cuttings, and other materials used or generated in connection with the permitted work. All drilling wastes must be controlled so as not to create conditions which violate applicable local, state and federal regulations. Discharge of drilling wastes into the sanitary sewer or storm drain is prohibited unless authorized by the county department of public works. This subsection does not modify the measures for proper handling, storage, and disposal of hazardous waste set forth in Health and Safety Code § 25100 et seq. (hazardous waste control) and by the state Code of Regulations, title 22, division 4.5 (environmental health standards for the management of hazardous waste).

(3) Mud pits. Mud pits created to confine drilling fluids shall be maintained during the well drilling operation so as not to be a nuisance. It shall be the applicant's responsibility to see that the mud pit is properly evacuated, or backfilled, or both evacuated and backfilled upon completion of the job.

(4) Abandoned wells. As a condition of well construction, modification, repair, inactivation, or destruction permits, and of pump installation, repair, or replacement permits, any abandoned wells on the property shall be destroyed or permitted for inactive status in accordance with standards provided in this division.

(5) Posting of permit. Except for an inactivation permit, it shall be the responsibility of the applicant to maintain a copy of this permit at the work site during all stages of permitted activities.

(f) Permit denial. The enforcement agency shall deny an application for a permit if:

(1) The applicant is not a person authorized to perform the work as provided by this division;

(2) The permit application is incomplete;

(3) The proposed work does not meet the standards adopted by this division; or

(4) Issuance of a permit does not fulfill the purpose of this division.

(g) Permit expiration. The applicant shall either complete the work authorized by the permit within one year of the date of issuance or forfeit permission to complete the work specified in the permit. If there have been exceptional circumstances, the enforcement agency may grant the applicant an extension. Such an extension shall be in writing and may contain additional permit conditions. Upon the expiration of the permit, no further work shall be done unless and until the applicant has received an extension or a new permit.

(h) Inactivation permits. An inactivation permit must be obtained for any well which has not been used for a period of one year, but which the owner intends to use again. Any such well which has not been permitted for inactive status by the enforcement agency is considered to be abandoned or permanently inactive and must be destroyed in accordance with applicable department of water resources' standards, pursuant to Health and Safety Code § 115700. Inactivation permits must be renewed annually. In addition to any conditions specified in the permit pursuant to subsection (e)(1) of this section, the applicant must maintain the well in such a way that the following requirements are met:

(1) The well shall not allow impairment of the quality of water within the well and groundwater encountered by the well.

(2) The top of the well and the well casing shall be provided with watertight covers, that are secured by locks or by other means to prevent their removal without the use of equipment or tools, to prevent unauthorized access, to prevent a safety hazard to humans and animals, and to prevent illegal disposal of wastes in the well. A pump motor, angle drive, or other surface feature of the well, when in compliance with this subsection, shall suffice as a cover.

(3) The well shall be marked so as to be easily visible and located, and labeled so as to be easily identified as a well.

(4) The area surrounding the well shall be kept clear of brush, debris, and waste materials.

(Ord. No. 97-01, § 2(6.28.030), 1-2-1997; Ord. No. 97-13, § 2, 3-26-1997; Ord. No. 97-17, § 2, 9-24-1997)

(a) Scope. The water well standards in this section have been designed to meet or exceed the water well standards contained in the department of water resources' bulletins 74-81 and 74-90.

(b) Well construction. Well construction shall be in accordance with the following:

(1) Well location with respect to pollutants and contaminants and structures. The well location, with respect to pollutants and contaminants and structures, shall be in accordance with the following:

a. Separation. All wells must be located an adequate horizontal distance from known or potential sources of pollution or contamination, as specified in the following table:

Lesser separation distances may be approved by the enforcement agency.

b. Gradients. Where possible, a well shall be located up the groundwater gradient from potential sources of pollution or contamination. Consideration should be given to the fact that the gradient near a well can be reversed by pumping (see bulletin 74-81, page 28, figure 3) or by other influences.

c. Flooding and drainage. New water wells and related appurtenances should be located above the regulatory flood datum (RFD) as established by the county department of public works, water resources division. If the well must be installed below the RFD, the following conditions shall apply:

1. The wellhead must be watertight. This includes chlorination ports, electrical connections, and any other connections or devices which may provide an avenue for entry of floodwater into the aquifer.

2. The pressure tank, electrical box, air vent, and other devices subject to flood damage or floodwater intrusion shall be located above the RFD.

3. To prevent floodwater from entering the aquifer if a water line break occurs, an approved checkvalve shall be installed on the main water line within three feet of the wellhead.

4. Surface drainage shall be directed away from the well.

d. Accessibility. All wells shall be located an adequate distance from buildings and other structures to allow access for well modification, maintenance, repair, and destruction, unless otherwise approved by the enforcement agency.

(2) Sealing upper annular space. Sealing of the upper annular space shall be in accordance with the following:

a. Minimum depth of annular surface seal. The annular surface seal shall extend from ground surface to a depth of at least 50 feet and shall anchor in a satisfactory, impervious stratum. This depth is referred to as the "minimum annular seal depth".

1. Shallow groundwater. Exceptions to the minimum seal depth may be made for shallow wells at the approval of the enforcement agency, where the water to be produced is at a depth less than 50 feet. In no case shall an annular seal extend to a total depth less than ten feet below land surface.

2. Vaults. At the approval of the enforcement agency, the top of an annular surface seal and well casing may be below ground surface where traffic or other conditions require, if the seal and casing extend to a watertight and structurally sound subsurface vault, or equivalent feature. In no case shall the top of the annular surface seal be more than four feet below ground surface. The vault shall extend from the top of the annular seal to at least ground surface.

b. Sealing conditions. The following requirements are to be observed for sealing the annular space. For wells situated in circumstances different from those described as follows, the sealing conditions shall be as prescribed by the enforcement agency:

1. Wells drilled in unconsolidated caving material. An oversized hole, at least four inches greater in diameter than the outside diameter of the well casing, shall be drilled and a conductor casing, such as hollow stem augers, temporarily installed to at least the minimum annular seal depth. Permanent conductor casing may be used if it is installed in accordance with subsections (b)(2)b.3, which pertains to wells drilled in soft consolidated formations, and (b)(2)b.5, which pertains to gravel packed wells with conductor casing, of this section and if it extends at least to the minimum annular seal depth.

Temporary conductor casing shall be withdrawn as sealing material is placed between the well casing and borehole wall (see bulletin 74-81, page 31, figure 4A). Sealing material shall be placed at least to the minimum annular seal depth. The sealing material shall be kept at a sufficient height above the bottom of the temporary conductor casing as it is withdrawn to prevent caving of the borehole wall.

Temporary conductor casing may be left in place in the borehole after the placement of the annular seal only at the approval of the enforcement agency on a case-by-case basis.

2. Wells drilled in unconsolidated material with significant clay layers. An oversized hole, at least four inches greater in diameter than the outside diameter of the well casing, shall be drilled to at least the minimum annular seal depth, and the annular space between the borehole wall and the well casing shall be filled with sealing material in accordance with subsection (b)(2)a of this section, which pertains to minimum depth of annular surface seal (see bulletin 74-81, page 31, figure 4B). If a significant layer of clay or clay-rich deposits of low permeability is encountered within five feet of the minimum annular seal depth, the annular seal shall be extended at least five feet into the clay layer. If the clay layer is known to be less than five feet in total thickness, the clay layer shall not be fully penetrated.

If caving material is present within the minimum annular seal depth interval, a temporary conductor casing shall be installed to hold the borehole open during well drilling and placement of the casing and annular seal, in accordance with the requirements of subsection (b)(2)b.1 of this section, which pertains to wells drilled in unconsolidated caving material. Permanent conductor casing may be used if it is installed in accordance with subsections (b)(2)b.3, which pertains to wells drilled in soft consolidated formations, and (b)(2)b.5, which pertains to gravel packed wells with conductor casing, of this section and it extends to at least the minimum annular seal depth.

3. Wells drilled in soft consolidated formations (extensive clays, sandstones, etc.). An oversized hole, at least four inches greater in diameter than the outside diameter of the well casing, shall be drilled to at least the minimum annular seal depth. The space between the well casing and the borehole shall be filled with sealing material to at least the minimum annular seal depth (see bulletin 74-81, page 31, figure 4C).

If a permanent conductor casing is to be installed to facilitate the construction of the well, an oversized hole, at least four inches greater in diameter than the outside surface of the permanent conductor casing, shall be drilled to the bottom of the conductor casing or to at least the minimum annular seal depth, and the annular space between the conductor casing and the borehole wall shall be filled with sealing material. In some cases, such as in cable tool drilling, it may be necessary to extend permanent conductor casing beyond the required depth of the annular surface seal in order to maintain the borehole. Sealing material is not required between conductor casing and the borehole wall other than the minimum annular seal depth or the depth specified in subsection (b)(6) of this section, which pertains to sealing-off strata.

4. Wells situated in hard consolidated formations (crystalline or metamorphic rock). An oversized hole shall be drilled to the minimum annular seal depth, and the annular space shall be filled with sealing material. If there is significant overburden, a conductor casing may be installed to retain it. If the well is to be open-bottomed (lower section uncased), the casing shall be seated in the sealing material (see bulletin 74-81, page 33, figure 5A).

5. Gravel packed wells with conductor casing. An oversized hole, at least four inches greater in diameter than the conductor casing, shall be drilled to the minimum annular seal depth, and the annular space between the conductor casing and the borehole shall be filled with sealing material. In this case, the gravel pack may extend to the top of the well, but, to prevent contamination by surface drainage, a welded cover shall be installed over the top in the space between the conductor casing and the well casing (see bulletin 74-81, page 33, figure 5B).

6. Gravel packed wells without conductor casing. An oversized hole, at least four inches greater in diameter than the well casing, shall be drilled to the minimum annular seal depth, and the annular space between the well casing and the borehole shall be filled with sealing material. If gravel fill pipes are installed through the seal, the annular seal shall be of sufficient thickness to ensure that there is a minimum of two inches between the gravel fill pipe and the borehole wall. The gravel pack shall terminate at the base of the seal (see bulletin 74-81, page 33, figure 5C). If a temporary conductor casing is used, it shall be removed as the sealing material is placed.

7. Converted wells. Wells converted from one use to another, particularly those constructed in prior years without annular seals, shall have annular seals installed to the minimum annular seal depth and at the thickness described in subsection (b)(2)e of this section, which pertains to radial thickness of seal.

8. Wells that penetrate zones containing poor-quality water, pollutants, or contaminants. If geologic units or fill known to contain poor-quality water, pollutants, or contaminants are penetrated during drilling, and the possibility exists that poor-quality water, pollutants, or contaminants could move through the borehole during drilling and well construction operations and significantly degrade groundwater quality in other units before sealing material can be installed, precautions (e.g., conductor casing, borehole liners, special drilling equipment, etc.) shall be taken to isolate zones containing poor-quality water, pollutants, or contaminants during drilling and well construction operations.

c. Conductor casing. For community water supply wells, the minimum thickness of steel conductor casing shall be one-fourth inch for single casing, or a minimum of No. 10 U.S. standard gage for double casing. Steel used for conductor casing shall conform to the specifications for steel casing described in subsection (b)(5) of this section, which pertains to casing.

d. Sealing material. Sealing material shall consist of neat cement, sand cement, or concrete. Cuttings from drilling, or drilling mud, shall not be used for any part of the sealing material.

1. Water. Water used to prepare sealing mixtures should generally be of drinking water quality, shall be compatible with the type of sealing material used, be free of petroleum and petroleum products, and be free of suspended matter.

2. Cement. Cement used in sealing mixtures shall meet the requirements of American Society for Testing and Materials C150, Standard Specification for Portland Cement, including the latest revisions thereof. Special cement setting accelerators and retardants and other additives may be used in some cases. Special field additives for Portland cement mixtures shall meet the requirements of ASTM C494, Standard Specification for Chemical Admixtures for Concrete, including the latest revisions thereof. Cement-based sealing materials shall be constituted as follows:

i. Neat cement. Neat cement shall be mixed at a ratio of one 94-pound sack of Portland cement to five to six gallons of clean water.

ii. Sand cement. Sand cement shall be mixed at ratio of not more than 188 pounds of sand to one 94-pound sack of Portland cement (two parts sand to one part cement, by weight) and about seven gallons of clean water. This is equivalent to a "10.3 sack mix."

iii. Concrete. Concrete shall consist of Portland cement and aggregate mixed at a ratio of at least six 94-pound sacks of Portland cement per cubic yard of aggregate. In no case shall the size of the aggregate be greater than one-fifth the radial thickness of the annular seal.

iv. Mixing. Cement-based sealing materials shall be mixed thoroughly to provide uniformity and ensure that no lumps exist.

v. Variations. Ratios of the components of cement-based sealing materials can be varied, depending upon the type of cement and additives used. Enforcement agency approval of variations must be received prior to placement.

3. Bentonite. Bentonite is allowed as an additive to cement-based sealing mixes, at a ratio of up to six percent by weight of cement used, or as a foundation or transition seal, as described in subsection (b)(2)f.3 of this section, which pertains to foundation and transition seals.

e. Radial thickness of seal. A minimum of two inches of sealing material shall be maintained between all casings and the borehole wall, within the interval to be sealed, except where temporary conductor casing can not be removed, as noted in subsection (b)(2)b.1 of this section, which pertains to wells drilled in unconsolidated caving material. A minimum of two inches of sealing material shall also be maintained between each casing, such as permanent conductor casing, well casing, gravel fill pipes, etc., in a borehole within the interval to be sealed, unless otherwise approved by the enforcement agency. Additional space shall be provided, where needed, for casings to be properly centralized and spaced and allow the use of a tremie pipe during well construction, if required, especially for deeper wells.

f. Placement of seal. The placement of the seal shall be in accordance with the following:

1. Obstructions. All loose cuttings or other obstructions to sealing shall be removed from the annular space before placement of the annular seal.

2. Centralizers. Well casing shall be equipped with centralizers to ensure the two-inch minimum radial thickness of the annular space is maintained. Centralizers need not be used in cases where the well casing is centered in the borehole during well construction by use of removable tools, such as hollow-stem augers.

Centralizers shall be metal, plastic, or other nondegradable material. Centralizers must be positioned to allow the proper placement of sealing material around the casing within the interval to be sealed.

Any metallic component of a centralizer used with metallic casing shall consist of the same material as the casing. Metallic centralizer components shall meet the same metallurgical specifications and standards as the metallic casing to reduce the potential for galvanic corrosion of the casing.

3. Foundation and transition seals. A packer or similar retaining device, or a small quantity of sealant that is allowed to set, may be placed at the bottom of the interval to be sealed before the final sealing operations begin to form a foundation for the seal.

A transition seal, up to five feet in length, consisting of bentonite or fine sand, must be placed in the annular space to separate filter pack and cement-based sealing materials.

Transition seals shall be installed by use of a tremie pipe or equivalent. Water shall be added to the bentonite transition seal prior to placement of cement-based sealing materials where bentonite is dry in the borehole. Water shall be added to the bentonite at a ratio of one gallon for every two pounds of bentonite to allow for proper hydration. A minimum of one-half hour shall be allowed for bentonite transition seals to properly hydrate before cement-based sealing materials are placed.

4. Timing and method of placement. The annular space shall be sealed as soon as practical after completion of drilling or a stage of drilling. In no case shall the annular space be left unsealed longer than 14 days following the installation of casing.

As a minimum, the uppermost 50 feet of sealing material shall be placed in one continuous operation.

Sealing material shall be placed by methods, such as the use of a tremie pipe or equivalent, that prevent freefall, bridging, or dilution of the sealing material, or separation of sand or aggregate from the sealing material. Annular sealing materials shall not be installed by freefall unless the interval to be sealed is dry and no deeper than 30 feet below ground surface.

5. Groundwater flow. Special care shall be used to restrict the flow of groundwater into a well boring while placing material, where subsurface pressure causing the flow of water is significant.

6. Verification. The applicant shall verify to the enforcement agency that the volume of sealing material placed at least equals or exceeds the volume to be sealed.

(3) Surface construction features. Surface construction features shall be as follows:

a. Openings. Openings into the top of the well which are designed to provide access to the well, i.e., for measuring, chlorinating, adding gravel, etc., shall be protected against entrance of surface waters or foreign matter by installation of watertight caps or plugs. Access openings designed to permit the entrance or egress of air or gas (air or casing vents) shall terminate above the ground and above the regulatory flood datum and shall be protected against the entrance of foreign material by installation of downturned and screened U-bends (see bulletin 74-81, pages 37 and 38, figures 6 and 7). All other openings (holes, crevices, cracks, etc.) shall be sealed.

A sounding tube, taphole with plug, or similar access for the introduction of water level measuring devices shall be affixed to the casing of all wells. For wells fitted with a well cap, the cap shall have a removable plug for this purpose.

1. Where the pump is installed directly over the casing, a watertight seal or gasket shall be placed between the pump head and the pump base (slab), or between the pump base and the rim of the casing, or a well cap shall be installed to close the annular opening between the casing and the pump column pipe (see bulletin 74-81, pages 37 and 38, figures 6 and 7).

2. Where the pump is offset from the well or where a submersible pump is used, the opening between the well casing and any pipes or cables which enter the well shall be closed by a watertight seal or well cap.

3. If the pump is not installed immediately or if there is a prolonged interruption in construction of the well, a watertight cover shall be installed at the top of the casing.

4. A watertight seal or gasket shall be placed between the pump discharge head and the discharge line, or, for a belowground discharge, between the discharge pipe and the discharge line (see bulletin 74-81, pages 37 and 38, figures 6 and 7).

5. A concrete base or pad, sometimes called a pump block or pump pedestal, shall be constructed at ground surface around the top of the well casing and contact the annular seal, unless the top of the casing is below ground surface, as provided by subsection (b)(3)b of this section, which pertains to well pits or vaults.

The base shall be free of cracks, voids, or other significant defects likely to prevent water tightness. Contacts between the base and the annular seal, and the base and the well casing, must be watertight and must not cause the failure of the annular seal or well casing. Where cement-based annular sealing material is used, the concrete base shall be poured before the annular seal has set, unless otherwise approved by the enforcement agency.

The upper surface of the base shall slope away from the well casing. The base shall extend at least two feet laterally in all directions from the outside of the well boring, unless otherwise approved by the enforcement agency. The base shall be a minimum of four inches thick.

6. Where the well is to be gravel packed and the pack extends to the surface, a watertight cover shall be installed between the conductor casing and the inner casing. See subsection (b)(2)b.5 of this section, which pertains to gravel packed wells with conductor casing; subsection (b)(2)b.6 of this section, which pertains to gravel packed wells without conductor casing; and bulletin 74-81, page 33, figure 5.

b. Well pits or vaults. Well pits or vaults may only be used if approval is obtained from the enforcement agency. If a pit or vault is used, it shall be watertight and structurally sound. The vault shall extend from the top of the annular seal to at least ground surface.

The casing shall extend at least six inches above the top of the annular seal.

The vault shall contact the annular seal in a manner to form a watertight and structurally sound connection. Contacts between the vault and the annular seal, and the vault and the well casing, if any, shall not fail or cause the failure of the well casing or annular seal.

Where cement-based annular seal materials are used, the vault shall be set into or contact the annular seal material before it sets, unless otherwise approved by the enforcement agency.

Cement-based sealing material shall be placed between the outer walls of the vault and the excavation into which it is placed to form a proper, structurally sound foundation for the vault, and to seal the space between the vault and excavation.

The sealing material surrounding a vault shall extend from the top of the annular seal to ground surface. If cement-based sealing material is used for both the annular seal and the space between the excavation and vault, the cement-based sealing material shall be placed between the vault and excavation and contact the cement-based annular seal before the annular seal has set

The vault cover or lid shall be watertight. The lid shall be fitted with a security device to prevent unauthorized access. The outside of the lid shall be clearly and permanently labeled "water well". The vault and its lid shall be strong enough to support vehicular traffic where such traffic might occur.

The top of the vault shall be set at, or above, grade so that drainage is away from the vault. The top of the well casing contained within the vault shall be covered in accordance with requirements under subsection (b)(3)a of this section, which pertains to openings, so that water, contaminants, and pollutants that may enter the vault will not enter the well casing. The cover shall be provided with a pressure relief or venting device for gases.

c. Enclosure of well and appurtenances. In community water supply wells, the well and pump shall be located in a locked enclosure to exclude access by unauthorized persons.

d. Pump blowoff. When there is a blowoff or drain line from the pump discharge, it shall be located above any known flood levels and protected against the possibility of backsiphonage or backpressure. The blowoff or drain line shall not be connected to any sewer or storm drain except when connected through an air gap.

e. Air vents. In community water supply wells to minimize the possibility of contamination caused by the creation of a partial vacuum during pumping, a casing vent shall be installed (see bulletin 74-81, page 38, figure 7). In addition, to release air trapped in the pump column when the pump is not running, air release vents shall be installed (see bulletin 74-81, page 38, figure 7). Air vents are also recommended for other types of wells except those having jet pump installations requiring positive pressure, which cannot have a vent.

f. Backflow prevention. All pump discharge pipes not discharging or open to the atmosphere shall be equipped with an automatic device to prevent backflow and/or backsiphonage into a well. Specific backflow prevention measures are required for drinking water supply wells, as prescribed in title 17, Public Health, California Code of Regulations (sections 7583—7585 and 7601—7605, effective June 25, 1987).

Irrigation well systems, including those used for landscape irrigation, and other well systems that employ, or which have been modified to employ, chemical feeders or injectors shall be equipped with a backflow prevention device approved by the enforcement agency.

All irrigation wells discharging to a standpipe shall be protected by air gap separation. Air gap separation shall mean a separation of at least two pipe diameters between the well discharge pipe and the rim of the standpipe.

(4) Disinfection and other sanitary requirements. Disinfection and other sanitary requirements are as follows:

a. Disinfection. All wells producing water for domestic use, i.e., drinking or food processing, should be disinfected following construction, repair, or when work is done on the pump, before the well is placed in service (see bulletin 74-81, appendix C, for a disinfection procedure).

b. Gravel. Gravel used in gravel packed wells shall come from clean sources and shall be thoroughly washed before placement into the well. Gravel purchased from a supplier shall be washed at the pit or plant prior to delivery to the well site.

During placement of the gravel in the annular space, disinfectants (usually calcium hypochlorite in tablet or granular form) shall be added to the gravel at a uniform rate (two tablets per cubic foot or one pound of the granular form per cubic yard).

c. Lubricants. Mud and water used as a drilling lubricant shall be free from sewage contamination. Oil and water used for lubrication of the pump and pump bearing shall also be free from contamination.

(5) Casing. Standards for casing shall be as follows:

a. Casing material. All casing material used in well construction shall be new. The following table is a minimum guideline for steel casing (the minimum gage pipe to be used in any well shall be 12 gage):

_____

MINIMUM THICKNESS FOR STEEL WATER WELL CASING

NOTE: Integers are United States standard gage; fractions are thickness, in inches

_____

1. Steel: standard and line pipe. This material shall meet one of the following specifications, including the latest revision thereof:

i. API Std. 5L, Specification for Line Pipe.

ii. API Std. 5LX, Specification for High-Test Line Pipe.

iii. ASTM A53, Standard Specification for Pipe, Steel, Black and Hot-Dipped, Zinc-Coated Welded and Seamless.

iv. ASTM A120, Standard Specification for Pipe, Steel, Black and Hot-Dipped Zinc-Coated (Galvanized) Welded and Seamless, for Ordinary Uses.

v. ASTM A134, Standard Specification for Electric Fusion (Arc)-Welded Steel Pipe (Sizes NPS 16 and over).

vi. ASTM A135, Standard Specification for Electric-Resistance-Welded Steel Pipe.

vii. ASTM A139, Standard Specification for Electric Fusion (Arc)-Welded Steel Pipe (Sizes 4 inches and over).

viii. ASTM A211, Standard Specification for Spiral-Welded Steel or Iron Pipe.

ix. AWWA C200, AWWA Standard for Steel Water Pipe 6 Inches and Larger.

2. Structural steel. This material shall meet one of the following specifications of the American Society of Testing and Materials (ASTM), including the latest revision thereof:

i. ASTM A36, Standard Specification for Structural Steel.

ii. ASTM A242, Standard Specification for High Strength Low Alloy Structural Steel.

iii. ASTM A283, Standard Specification for Low and Intermediate Tensile Strength Carbon Steel Plates of Structural Quality.

iv. ASTM A441, Standard Specification for High-Strength Low Alloy Structural Manganese Vanadium Steel.

v. ASTM A570, Standard Specification for Hot-Rolled Carbon Steel Sheet and Strip, Structural Quality.

3. High strength carbon steel sheets (well casing steel). At present, there are no standard specifications concerning this material. However, the major steel producers market products the chemical and physical properties of which are quite similar. Each sheet of material shall contain mill markings which will identify the manufacturer and specify that the material is well casing steel which complies with the chemical and physical properties published by the manufacturer.

4. Stainless steel. This casing shall meet the provisions of ASTM A409, Standard Specification for Welded Large Diameter Austenitic Steel Pipe for corrosive or High Temperature Service.

5. Plastic casing.

i. Thermoplastics. Thermoplastic well casing shall meet the requirements of ASTM F480, Standard Specification for Thermoplastic Well Casing Pipe and Couplings Made in Standard Dimension Ratios (SDR), SCH 40 and SCH 80, including the latest revision thereof.

Pipe made in schedule 40 and 80 wall thicknesses and pipe designated according to certain pressure classifications are listed in ASTM F480, as well as casing specials referencing the following ASTM specifications:

ABS pipe: ASTM D1527, Standard Specification for Acrylonitrile-Butadiene-Styrene (ABS) Plastic Pipe, Schedules 40 and 80.

PVC pipe: ASTM D1785, Standard Specification for Polyvinyl Chloride (PVC) Plastic Pipe, Schedules 40, 80, and 120.

Pressure-rated PVC pipe: ASTM D2241, Standard Specifications for Polyvinyl Chloride (PVC) Pressure-Rated Pipe (SDR Series).

Thermoplastic well casing that may be subject to significant impact stress during or after installation shall meet or exceed the requirements for impact resistance classification set forth in section 6.5 of ASTM F480. Casing that may be subject to significant impact forces includes but is not limited to casing that is installed in large diameter, deep boreholes; and casing through which drilling tools pass following installation of the casing in a borehole.

ii. Thermoset plastics. Thermoset casing material shall meet the following specifications, as applicable, including the latest revisions thereof:

Filament wound resin pipe: ASTM D2996, Standard Specification for Filament Wound Reinforced Thermosetting Resin Pipe.

Centrifugally cast resin pipe: ASTM D2997, Standard Specification for Centrifugally Cast Reinforced Thermosetting Resin Pipe.

Reinforced plastic mortar pressure pipe: ASTM D3517, Standard Specification for Reinforced Plastic Mortar Pressure Pipe.

Glass fiber reinforced resin pressure pipe: AWWA C950, AWWA Standard for Glass-Fiber-Reinforced Thermosetting-Resin Pressure Pipe.

iii. Drinking water supply. All plastic casing used for drinking water supply wells, including community supply wells and individual domestic wells, shall meet the provisions of National Sanitation Foundation Standard No. 14, Plastic Piping Components and Related Materials, and any revision thereof. The casing shall be marked or labeled following requirements in NSF Standard No. 14, which includes the requirements of ASTM F480.

iv. Storage, handling, and transportation. Plastic casing shall not be stored in direct sunlight or subjected to freezing temperatures for extended periods of time. Plastic casing shall be stored, handled, and transported in a manner that prevents excessive mechanical stress. Casing shall be protected from sagging and bending, severe impacts and loads, and potentially harmful chemicals.

v. Large diameter wells. Because large diameter plastic casing has not been used extensively at depths exceeding 500 feet, special care shall be exercised with its use in deep wells.

6. Concrete casing. Concrete pipe used for casing should conform to the following specifications, including the latest revision thereof:

i. ASTM C14, Standard Specification for Concrete Sewer, Storm Drain, and Culvert Pipe.

ii. ASTM C76, Standard Specification for Reinforced Concrete Culvert, Storm Drain, and Sewer Pipe.

iii. AWWA C300, AWWA Standard for Reinforced Concrete Pressure Pipe Steel Cylinder Type, for Water and Other Liquids.

iv. AWWA C301, AWWA Standard for Prestressed Concrete Pressure Pipe, Steel Cylinder Type, for Water and Other Liquids.

7. Unacceptable casing materials. Galvanized sheetmetal pipe such as downspout, tile pipe, or natural wood shall not be used as well casing.

8. Other materials. Materials in addition to those described in this subsection may be used as well casing, subject to enforcement agency approval.

b. Casing installation. All well casing shall be assembled and installed with sufficient care to prevent damage to casing sections and joints. All casing joints above intervals of perforations or screen shall be watertight. Any perforations shall be below the minimum annular seal depth.

Watertight construction of the cased portion of the well shall be carried into an impervious subsurface formation which caps the aquifer. The casing may penetrate more than one aquifer.

The casing shall extend a minimum distance of 12 inches above grade or 12 inches above the regulatory flood datum, except on prior approval of the enforcement agency.

Casing shall be equipped with centering guides or centralizers to ensure the even radial thickness of the annular seal and filter pack.

1. Metallic casing. Metallic casing may be joined by welds, threads, or threaded couplings. Welding shall be accomplished in accordance with the standards of the American Welding Society or the most recent revision of the American Society of Mechanical Engineers Boiler Construction Code. Metallic casing shall be equipped with a drive shoe at the lower end if it is driven into place.

2. Plastic casing. Plastic casing may be joined by solvent welding or mechanically joined by threads or other means, depending on the type of material and its fabrication. Solvent cement used for solvent welding shall meet specifications for the type of plastic casing used. Solvent cement shall be applied in accordance with solvent and casing manufacturer instructions. Particular attention shall be given to instructions pertaining to required setting time for joints to develop strength.

The following specifications for solvent cements and joints for PVC casing shall be met, including the latest revisions thereof:

i. ASTM D2564, Standard Specification for Solvent Cements for Polyvinyl Chloride (PVC) Plastic Pipe and Fittings.

ii. ASTM D2855, Standard Practice for Making Solvent-Cemented Joints with Polyvinyl Chloride (PVC) Pipe and Fittings.

Plastic casing or screen shall not be subjected to excessive stress during installation and shall not be driven into place. Care shall be taken to ensure that plastic casing and joints are not subjected to excessive heat from cement-based sealing material.

A specifically designed adapter shall be used to join plastic casing to metallic casing or screen.

(6) Sealing-off strata. In areas where a well penetrates more than one aquifer, and one or more of the aquifers contains water that, if allowed to mix in sufficient quantity, will result in a significant deterioration of the quality of water in the other aquifers or the quality of water produced, the strata producing such poor-quality water shall be sealed off to prevent entrance of the water into the well or its migration to other aquifers.

a. Strata producing the undesirable quality water shall be sealed off by placing impervious material opposite the strata and opposite the confining formation (see bulletin 74-81, page 47, figure 8). The seal shall extend above and below the strata no less than ten feet, even should the confining formation be less than ten feet in thickness. For bottom waters, the seal shall extend ten feet in the upward direction. The sealing material shall fill the annular space between the casing and the well of the drilled hole in the interval to be sealed and the surrounding void spaces which might absorb the sealing material. The sealing material shall be placed from the bottom to the top of the interval to be sealed.

In areas where deep subsidence may occur, provision shall be made for maintaining the integrity of the annular seal if subsidence occurs. Such preventative measures may include the installation of a sleeve or a slip joint in the casing, which will allow vertical movement in the casing without its collapse.

b. Sealing material shall consist of neat cement or sand cement, as described in subsection (b)(2)d of this section, which pertains to sealing material.

c. Sealing shall be accomplished by a method approved by the enforcement agency (see bulletin 74-81, appendix B, for suggested methods).

(7) Well development. Development, redevelopment, or reconditioning of a well shall be performed with care, by methods that will not damage the well structure or destroy natural barriers to the movement of poor-quality water, pollutants, and contaminants. Acceptable well development, redevelopment, or reconditioning methods include the following:

a. Overpumping;

b. Surging or swabbing by use of plungers;

c. Surging with compressed air;

d. Backwashing or surging by alternately starting and stopping a pump;

e. Jetting with water;

f. Introducing specifically formulated chemicals into a well; and

g. Combinations of subsection (b)(7)a through (b)(7)f of this section.

Hydraulic fracturing (hydrofracturing) is sometimes an acceptable well development and redevelopment method when properly performed. Good quality water shall be used in hydrofracturing. The water shall be disinfected prior to introduction into a well. Material used as propping agents shall be free of pollutants and contaminants, shall be compatible with the use of the well, and shall be thoroughly washed and disinfected prior to placement in the well.

Development, redevelopment, or reconditioning by use of specially designed explosive charges is, in some cases, another acceptable development method. Explosives shall be used with special care to prevent damage to the well structure and to any natural barriers to the movement of poor-quality water, pollutants, and contaminants. Explosives shall only be used by properly trained personnel.

Wells subjected to chemicals or explosives during development, redevelopment, or reconditioning operations shall be thoroughly pumped to remove such agents and residues immediately after the completion of operations. Chemicals, water, and other wastes removed from the well shall be disposed of in accordance with applicable local, state, and federal requirements. The enforcement agency should be contacted regarding the proper disposal of waste.

(8) Water quality sampling. Water quality sampling shall be in accordance with the following:

a. Community water supply wells and certain industrial wells. The water from all community water supply wells and industrial wells which provide water for use in food processing shall be sampled immediately following development and disinfection, and appropriate analysis made.

Rules and regulations governing the constituents to be tested, type of testing, etc., for community water supply systems are contained in chapter 15, Domestic Water Quality and Monitoring, of title 22, California Code of Regulations. Water analysis shall be performed by a laboratory certified by the state department of health services. A copy of the laboratory analysis shall be forwarded to the state department of health services or to the enforcement agency. Approval of the enforcement agency must be obtained before the well is put into use.

Except where there is free discharge from the pump (i.e., no direct connection to the water delivery system such as to a sump), a sample tap (see bulletin 74-81, page 38, figure 7) shall be provided on the discharge line so that water representative of the water in the well may be drawn for laboratory analysis. The tap shall be located so as to prevent backsiphonage to the pump discharge when the pump is shut off (e.g., on the system side of the checkvalve).

b. Other types of wells. To determine the quality of water produced by a new well, it should be sampled immediately following construction and development. Appropriate analyses shall be made based upon the intended uses of the water.

(9) Special provisions for large diameter shallow wells. Special provisions for large diameter shallow wells are as follows:

a. Use as community water supply wells. Because shallow groundwaters are often of poor quality and because they are easily contaminated, the use of bored or dug wells, or wells less than 50 feet deep, to provide community water supplies shall be avoided, unless there is no other feasible means for obtaining water. When used for this purpose, these wells shall be located at least 250 feet from any underground sewage disposal facility.

b. Bored wells. All bored wells shall be cased with concrete pipe or steel casing the joints of which are watertight from six inches above the ground surface to the minimum annular seal depth. Except where corrugated steel pipe is used as casing, the minimum thickness of the surrounding concrete seal shall be three inches. Where corrugated steel pipe is employed, the joints are not watertight, and a thicker annular seal (no less than six inches) shall be installed.

c. Dug wells. All dug wells shall be curbed with a watertight curbing extending from above the ground surface to the minimum annular seal depth. The curbing shall be of concrete poured in place or of casing, either precast concrete pipe or steel, surrounded on the outside by concrete.

If the curbing is to be made of concrete, poured in place, it shall not be less than six inches thick. If precast concrete pipe or steel casing is used as part of the curbing, the space between the wall of the hole and the casing shall be filled with concrete to the minimum annular seal depth. The minimum thickness of the surrounding concrete shall be three inches.

d. Casing material. Either steel, including corrugated steel pipe, or concrete may be used for casing bored or dug wells.

1. Steel used in the manufacture of casing for bored and dug wells should conform to the specifications for casing material described in subsection (b)(5) of this section, which pertains to casing. Minimum thickness of steel casing for bored and dug wells shall be as follows:

Corrugated steel pipe used as casing shall meet the specifications, including the latest revision, of ASTM A444, Standard Specification for Steel Sheet, Zinc Coated (Galvanized) by the HOT-DIP Process for Culverts and Underdrains. The minimum thickness of sheet used shall be 0.109 inch.

2. Concrete casing can consist of either poured-in-place concrete or precast concrete pipe. Poured-in-place concrete should be sufficiently strong to withstand the earth and water pressures imposed on it during, as well as after, construction. It should be properly reinforced with steel to furnish tensile strength and to resist cracking, and it should be free from honeycombing or other defects likely to impair the ability of the concrete structure to remain watertight. Aggregate small enough to place without bridging should be used. Poured-in-place concrete shall be class A (six sacks of Portland cement per cubic yard) or class B (five sacks per cubic yard).

Precast concrete pipe is usually composed of concrete rings from one to six feet in diameter and approximately three to eight feet long. To serve satisfactorily as casing, these rings should be free of blemishes that would impair their strength or serviceability. Concrete pipe shall conform to the specifications listed in subsection (b)(5)a.6 of this section, which pertains to concrete casing.

e. Covers. All bored or dug wells shall be provided with a structurally sound, watertight, cover made of concrete or steel.

(10) Special provisions for driven wells. Special provisions for driven wells (well points) are as follows:

a. If the well is to be used as an individual domestic well, an oversize hole with a diameter at least three inches greater than the diameter of the pipe shall be constructed to a depth of six feet, and the annular space around the pipe shall be filled with neat cement or sand-cement.

b. The minimum wall thickness of steel drive pipe shall be not less than 0.140 inch.

c. Well points made of thermoplastic materials shall not be driven but jetted or washed into place.

(11) Rehabilitation, repair, and deepening of wells. Rehabilitation, repair, and deepening of wells shall be in accordance with the following:

a. Rehabilitation is the treatment of a well by chemical or mechanical means, or both, to recover lost production caused by incrustation or clogging of screens or the formation immediately adjacent to the well. The following methods used for rehabilitating a well, when done with care, are acceptable:

1. Introduction of chemicals designed for this purpose;

2. Surging by use of compressed air;

3. Backwashing or surging by alternately starting or stopping the pump;

4. Jetting with water;

5. Sonic cleaning;

6. Vibratory explosives; and

7. Combinations of subsection (b)(11)a.1—6 of this section.

Methods which produce an explosion, in addition to the use of vibratory explosives mentioned in subsection (b)(11)a.6 of this section, are also acceptable; provided, however, they are used with great care, particularly where aquifers are separated by distinct barriers to the movement of groundwater.

When chemicals or explosives have been used, the well shall be pumped until all traces of them have been removed.

b. In the repair of wells, material used for casing shall meet the requirements specified in subsection (b)(5) of this section, which pertains to casing. In addition, the requirements contained in subsection (b)(4)a of this section, which pertains to disinfection, and subsection (b)(6) of this section, which pertains to sealing-off strata, shall be followed, when applicable.

c. Where wells are to be deepened, the requirements of subsection (b)(4) of this section, which pertains to disinfection and other sanitary requirements; subsection (b)(5) of this section, which pertains to casing; subsection (b)(6) of this section, which pertains to sealing-off strata; subsection (b)(7) of this section, which pertains to well development; and subsection (b)(8) of this section, which pertains to water quality sampling, shall be followed.

(12) Temporary cover. Whenever there is an interruption in work on the well such as overnight shutdown, during inclement weather, or waiting periods required for the setting-up of sealing materials, for tests, for installation of the pump, etc., the well opening shall be closed with a cover to prevent the introduction of undesirable material into the well and to ensure the public safety. The cover shall be held in place or weighted-down in such a manner that it cannot be removed except with the aid of equipment or through the use of tools.

During prolonged interruptions (i.e., one week or more), a semipermanent cover shall be installed. For wells cased with steel, a steel cover, tack-welded to the top of the casing, is adequate.

(c) Destruction of wells. Standards for the destruction of wells shall be as follows:

(1) Purpose of destruction. A well that is no longer useful, including exploration and test holes, must be destroyed in order to:

a. Ensure that the groundwater supply is protected and preserved for further use; and

b. Eliminate the potential physical hazard.

(2) Definition of abandoned well. A well is considered "abandoned" or permanently inactive if it has not been used for one year, unless the owner demonstrates intention to use the well again. In accordance with Health and Safety Code § 115700, the well owner shall properly maintain an inactive well as evidence of intention for future use in such a way that the following requirements are met:

a. The well shall not allow impairment of the quality of water within the well and groundwater encountered by the well.

b. The top of the well or well casing shall be provided with a cover, that is secured by a lock or by other means to prevent its removal without the use of equipment or tools, to prevent unauthorized access, to prevent a safety hazard to humans and animals, and to prevent illegal disposal of wastes in the well. The cover shall be watertight where the top of the well casing or other surface openings to the well are below ground level, as in a vault, or below known levels of flooding. The cover shall be watertight if the well is inactive for more than five consecutive years. A pump motor, angle drive, or other surface feature of a well, when in compliance with such provisions, shall suffice as a cover.

c. The well shall be marked so as to be easily visible and located, and labeled so as to be easily identified as a well.

d. The area surrounding the well shall be kept clear of brush, debris, and waste materials.

If a pump has been temporarily removed for repair or replacement, the well shall not be considered "abandoned" if the conditions of this subsection are met. The well shall be adequately covered to prevent injury to people and animals and to prevent the entrance of foreign material, surface water, pollutants, or contaminants into the well during the pump repair period.

(3) General requirements. General requirements shall be as follows:

a. All abandoned wells and exploratory holes (borings) shall be destroyed. Destruction shall consist of the complete filling of the well or exploratory hole in accordance with the procedures described in subsection (c)(4) of this section, which pertains to requirements for destroying wells.

b. Upon determination that a well is polluted or contaminated, and if reasonable efforts to clear the contamination have been unsuccessful, the enforcement agency shall have the authority to require the permanent destruction of the well.

(4) Requirements for destroying wells. Requirements for destroying wells shall be as follows:

a. Preliminary work. Preliminary work shall be conducted in accordance with the following:

1. Before the well is sealed, it shall be investigated to determine its condition, the details of construction, and whether there are obstructions that will interfere with the sealing process.

2. The well shall be cleaned, as needed, so that all undesirable materials, including obstructions to filling and sealing, debris, oil from oil-lubricated pumps, or pollutants and contaminants that could interfere with well destruction, are removed for disposal.

The enforcement agency should be contacted to determine requirements for proper disposal of materials removed from a well to be destroyed.

If an obstruction is hardware that cannot be removed, a tremie pipe must be passed below the obstruction to place sealing material to the full depth of the well, leaving the obstruction sealed inside the well.

3. When necessary, to ensure that sealing material also fills any voids in the annular space, the casing shall be perforated at the appropriate depth.

4. A hole, at least one foot larger in diameter than the drilled hole, shall be excavated around the well casing to a depth of five feet below ground surface. The well casing shall be cut off, six inches above the bottom of the excavation, and removed. The sealing material shall spill over into the excavation, forming a cap. After the sealing material has set, the excavation shall be filled with compacted native soil.

5. For dug wells, as much of the lining as possible, or safe, should be removed prior to filling.

6. Alternatively, a water well may be destroyed by removing all material within the original borehole, including the well casing, filter pack, and annular seal, and the created hole completely filled with appropriate sealing material.

b. Filling and sealing conditions. All wells shall be sealed so as to prevent interaquifer flow, either through the well or around the outside of the casing. Following are additional requirements to be observed when certain conditions are encountered:

1. Wells situated in unconsolidated material in an unconfined groundwater zone. In all cases, the upper 50 feet of the well shall be sealed with suitable sealing material, and the remainder of the well shall be filled with suitable fill, or sealing material (see bulletin 74-81, page 55, figure 9A).

2. Wells penetrating several aquifers or formations. In all cases, the upper 50 feet of the well shall be sealed with impervious material.

In areas where the interchange of water between aquifers will result in a significant deterioration of the quality of water in one or more aquifers, or will result in a loss of artesian pressure, the well shall be filled and sealed so as to prevent such interchange. Sand or other suitable inorganic material may be placed opposite the producing aquifers and other formations where impervious sealing material is not required. To prevent the vertical movement of water from the producing formation, impervious material must be placed opposite confining formations above and below the producing formations for a distance of ten feet or more. The formation producing the deleterious water shall be sealed by placing impervious material opposite the formation and opposite the confining formations for a sufficient vertical distance, but no less than ten feet, in both directions or, for bottom waters, in the upward direction (see bulletin 74-81, page 55, figure 9B).

In locations where the interchange is in no way detrimental, suitable inorganic material may be placed opposite the formations penetrated. When the boundaries of the various formations are unknown, alternate layers of impervious and pervious material shall be placed in the well.

3. Wells penetrating creviced or fractured rock. If creviced or fractured rock formations are encountered just below the surface, the portions of the well opposite this formation shall be sealed with neat cement, sand-cement grout, or concrete. If these formations extend to considerable depth, alternate layers of coarse stone (one-fourth to four inches) and cement grout or concrete may be used to fill the well. Fine grained material shall not be used as fill material for creviced or fractured rock formations.

4. Wells in noncreviced, consolidated formations. The upper 50 feet of a well in a noncreviced, consolidated formation shall be filled with impervious material. The remainder of the well may be filled with clay or other suitable inorganic material.

5. Wells penetrating specific aquifers under local conditions. Under certain local conditions, the enforcement agency may require that specific aquifers or formations be sealed off during destruction of the well.

c. Placement of material. Placement of material shall be in accordance with the following:

1. The well shall be filled with the appropriate material from the bottom of the well up.

2. As a minimum, the uppermost 50 feet of sealing material shall be placed in one continuous operation.

3. Sealing material shall be placed in the interval to be sealed by methods that prevent freefall, dilution, and/or separation of aggregates from cementing materials.

4. Where the head (pressure) producing flow is great, special care must be used to restrict the flow while placing the sealing material. In such cases, the casing must be perforated opposite the area to be sealed and the sealing material forced out under pressure into the surrounding formation.

5. In destroying gravel packed wells, the casing shall be perforated or otherwise punctured opposite the area to be sealed. The sealing material shall then be placed within the casing, completely filling the portion adjacent to the area to be sealed and then forced out under pressure into the gravel envelope.

6. When pressure is applied to force sealing material into the annular space, the pressure shall be maintained for a length of time sufficient for the cementing mixture to set.

7. To ensure that the well is filled and there has been no jamming or bridging of the material, the applicant shall verify that the volume of material placed in the well installation at least equals the volume of the empty hole.

d. Materials. Requirements for sealing and fill materials are as follows:

1. Acceptable impervious sealing materials include neat cement, sand cement grout, and concrete, as described in subsection (b)(2)d.2.iii of this section, which pertains to concrete. Up to six percent, by weight of cement used, bentonite may be added to these cement-based mixes.

2. Acceptable filler materials include sand and pea gravel.

3. Drill cuttings or drilling mud shall not be used for any part of the sealing process.

4. Water shall be clean and free of suspended matter and contaminants.

5. Cement shall meet ASTM C150, Standard Specification for Portland Cement.

6. Sand and pea gravel shall be washed and free of organic matter.

7. Bentonite shall be naturally mined (nonpelletized) sodium montmorillonite, listed by NSF, and shall be contained within the original manufacturer's container or sack.

8. Cement-based materials shall be constituted as described in subsection (b)(2)d.2 of this section, which pertains to cement.

e. Temporary cover. During periods when no work is being done on the well, such as overnight or while waiting for sealing material to set, the well and surrounding excavation, if any, shall be covered. The cover shall be sufficiently strong and well enough anchored to prevent the introduction of foreign material into the well and to protect the public from a potentially hazardous situation. During prolonged interruptions (i.e., one week or more), a semipermanent cover shall be installed.

(d) Pump standards. All pumps shall be constructed and installed so as to provide protection against contamination and pollution of the aquifers.

(1) Externally mounted pumps. Standards for externally mounted pumps shall be as follows:

a. The pump head shall be mounted on a concrete pedestal which slopes away from the pump head.

b. The pump head shall be sealed to the pedestal.

c. A concrete slab shall be poured to slope away from the pedestal. It shall extend at least two feet laterally in all directions from the outside of the well boring. The slab shall be a minimum of four inches thick and shall be continuous to the pedestal.

d. An air relief vent, when needed, shall be constructed of metal tubing or pipe. The vent shall extend at least six inches above the pump base. The end of the vent shall open downward and be protected by 16 or greater mesh screen.

e. A chlorination tube shall be installed into the casing with a continuous welded bead. This tube shall not protrude into the casing and shall have a screw cap at the exposed end.

f. A sampling tap shall be installed on the discharge line within three feet of the pump and between the checkvalve and well so that water representative of the water in the well may be drawn for laboratory analysis. A sample tap need not be installed on a single-family residence installation.

g. Any blowoff or drain lines from the pump discharge shall be so located that there is no hazard to the safety of the underground aquifers by reason of flooding or backsiphonage.

(2) Internally located pumps. Standards for internally located pumps shall be as follows:

a. The top of the casing shall be covered by a steel plate or other fixture which may be secured to the casing with a watertight seal. The openings in this plate or fixture, through which the water conductor pipe and electrical wires may enter the well, shall also have a watertight seal.

b. A chlorination port with screw plug shall be located in the plate or fixture, or a chlorination tube with a screw cap shall be installed in the casing.

c. A sampling tap shall be installed on the discharge line within three feet of the well and between the checkvalve and well so that water representative of the water in the well may be drawn for laboratory analysis. A sample tap need not be installed on a single-family residence installation.

d. A concrete slab shall be poured to slope away from the casing. It shall extend at least two feet laterally in all directions from the casing. The slab shall be a minimum of four inches thick and shall be continuous to the casing.

e. Any blowoff or drain lines from the pump discharge shall be so located that there is no hazard to the safety of the underground aquifers by reason of flooding or backsiphonage.

(Ord. No. 97-01, § 2(6.28.040), 1-2-1997; Ord. No. 97-13, § 2, 3-26-1997; Ord. No. 97-17, § 2, 9-24-1997)

(a) General requirements. General requirements for monitoring wells are as follows:

(1) Application to well type. The standards in this section apply to all types of monitoring wells, as well as to vapor extraction wells, where applicable, and any other well installed in an area where special precautions are necessary to protect groundwater quality, except as prescribed in subsection (a)(2) of this section, which pertains to exemptions for unusual conditions, and subsection (a)(3) of this section, which pertains to exclusions. Before a change in use of a well is made, any standards for the new use must be complied with.

(2) Exemptions for unusual conditions. Under certain circumstances, the enforcement agency may waive compliance with these standards and prescribe alternate requirements. These standards may be waived where they are impractical or ineffective because of unusual conditions or would result in an unsatisfactory condition or well function. In waiving any of these standards, the enforcement agency shall, if at all possible, require measures be implemented to provide the same or greater level of water quality protection that would otherwise be provided by these standards.

(3) Exclusions. Most standards in subsection (b) of this section, which pertains to monitoring well construction, do not apply to exploration holes. However, subsection (c) of this section, which pertains to destruction of monitoring wells, and section 98-62, which pertains to well completion reports, do apply directly to exploration holes.

(4) Special standards. The enforcement agency may prescribe measures more stringent than standards presented in this section, where needed to protect public safety or protect water quality.

(b) Monitoring well construction. Construction standards for monitoring wells are as follows:

(1) Well location with respect to pollutants and contaminants, and structures. Standards for well location, with respect to pollutants and contaminants, and structures are as follows:

a. Separation. Monitoring wells shall be located an adequate distance from known or potential sources of pollution and contamination, including those listed in section 98-55(b)(1)a, which pertains to separation, of the water well standards, unless regulatory or legitimate data requirements necessitate they be located closer.

b. Flooding and drainage. Monitoring wells should be located in areas protected from flooding, if possible. Provisions for locating monitoring wells in areas of flooding and drainage are contained in section 98-55(b)(1), which pertains to flooding and drainage, of the water well standards.

c. Accessibility. All monitoring wells shall be located an adequate distance from buildings and other structures to allow access for well maintenance, modification, repair, and destruction, unless otherwise approved by the enforcement agency.

d. Disposal of wastes when drilling in contaminated or polluted areas. Drill cuttings and wastewater from monitoring wells or exploration holes in areas of known or suspected contamination or pollution shall be disposed of in accordance with all applicable federal, state, and local requirements. The enforcement agency should be contacted to determine requirements for the proper disposal of cuttings and wastewater.

(2) Sealing the upper annular space. General discussion of sealing methods and requirements for monitoring wells is contained in section 98-55(b)(2), which pertains to sealing the upper annular space, of the water well standards. Special requirements for monitoring wells include the following:

a. Minimum depth of annular seal. The minimum depth of annular seal shall be in accordance with the following:

1. Water quality monitoring wells and monitoring wells constructed in areas of known or suspected pollution or contamination. The annular space shall be sealed from the top of the filter pack or monitoring zone to ground surface, unless otherwise approved by the enforcement agency. The top of the filter pack or monitoring zone shall not extend into another water-bearing unit above the single water-bearing unit being monitored unless otherwise approved by the enforcement agency. The filter pack or monitoring zone shall not extend into any confining layers that overlie or underlie the unit to be monitored, unless otherwise approved by the enforcement agency. The annular surface seal shall be no less than 50 feet in length.

Seal lengths less than 50 feet are permissible only if shallow zones will be monitored and approval has been obtained from the enforcement agency.

2. Other monitoring wells. The upper annular seal shall extend from the ground surface to a minimum depth of 50 feet. An annular seal less than 50 feet in length is permissible if provisions in subsection (b)(2)a.1 of this section, which pertains to water quality monitoring wells and monitoring wells constructed in areas of known or suspected pollution or contamination, are followed.

3. Sealing-off strata. Additional annular sealing material shall be placed below the minimum depth of the upper annular seal, as is needed, to prevent the movement of poor-quality water, pollutants, and contaminants through the well to zones of good quality water. Requirements for sealing off zones are in section 98-55(b)(6), which pertains to sealing-off strata, of the water well standards.

4. Vaults. At the approval of the enforcement agency, the top of the annular seal and well casing can be below ground surface where traffic or other conditions require. In no case shall the top of the annular seal be more than four feet below ground surface.

The top of the annular seal shall contact a suitable, watertight, structurally sound subsurface vault, or equivalent feature, that encloses the top of the well casing in accordance with subsection (b)(3)e of this section, which pertains to vaults. The vault shall extend from the top of the annular seal to at least ground surface.

b. Sealing conditions. Sealing conditions are as follows:

1. Temporary conductor casing. If temporary conductor casing is used during drilling, it shall be removed during the placement of the casing and annular seal materials, as described in section 98-55(b)(2), which pertains to sealing the upper annular space, of the water well standards. If the temporary conductor casing cannot be removed, as defined in section 98-55(b)(2), sealing material shall be placed between the conductor casing and borehole wall and between the well casing and conductor casing, in accordance with methods described in section 98-55(b)(2). Sealing material shall extend to at least the depths specified in subsection (b)(2)a of this section, which pertains to minimum depth of annular seal.

2. Permanent conductor casing. If a permanent conductor casing is to be installed, the monitoring well borehole diameter shall be at least four inches greater than the outside diameter of the conductor casing. The inner diameter of the permanent conductor casing shall in turn be at least four inches greater than the outside diameter of the well casing.

Sealing material shall be placed between the permanent conductor casing and the borehole wall and the conductor casing and the well casing. The sealing material shall extend to at least the depths specified in subsection (b)(2)a of this section, which pertains to minimum depth of annular seal.

c. Radial thickness of seal. A minimum of two inches of sealing material shall be maintained between all casings and the borehole wall, within the interval to be sealed, except as noted in section 98-55(b)(2), which pertains to sealing the upper annular space, of the water well standards. At least two inches of sealing material shall also be maintained between all casings in a borehole, within the interval to be sealed, unless otherwise approved by the enforcement agency. Additional space shall be provided, where needed, to allow casings to be properly centralized and spaced and allow the use of a tremie pipe during well construction, if required, especially for deeper wells.

d. Sealing material. Sealing material shall consist of neat cement or sand cement. Concrete shall be used only with the approval of the enforcement agency.

Sealing material shall be selected based on required structural, handling, and sealing properties, and the chemical environment into which it is placed. Used drilling mud or cuttings from drilling shall not be used for any part of the sealing material.

1. Water. Water used for sealing mixtures should generally be of drinking water quality, shall be compatible with the type of sealing material used, shall be free of petroleum and petroleum products, and shall be free of suspended matter. Only drinking-quality water of known composition should be used for preparing sealing mixtures for monitoring wells to be used for sensitive water-quality determinations.

2. Cement-based sealing materials. Standards for cement-based sealing materials are contained in section 98-55(b)(2), which pertains to sealing the upper annular space, of the water well standards. Special considerations that apply to monitoring wells are as follows:

i. Additives. Care should be exercised in the use of special additives for cement-based sealing materials, such as those used for modifying cement setting times. Some additives could interfere with sensitive water quality determinations.

ii. Cooling water. For water quality monitoring wells, care should be exercised in the use of circulating cooling water to protect plastic casing from heat buildup during setting of cement-based sealing materials. Water introduced and/or circulated in a well for cooling could interfere with water quality determinations.

e. Transition seal. A bentonite-based or fine sand transition seal, up to five feet in length, must be placed in the annular space to separate filter pack and cement-based sealing materials, as described in section 98-55(b)(2)f.3, which pertains to foundation and transition seals, of the water well standards.

f. Placement of annular seal material. All loose cuttings and other obstructions shall be removed from the annular space before sealing materials are placed. Sealing may be accomplished by using pressure grouting techniques, a tremie pipe, or equivalent. Sealing materials shall be installed as soon as possible during well construction operations. Sealing materials shall not be installed by freefall from the surface unless the interval to be sealed is dry and less than 30 feet deep.

Casing spacers shall be used within the interval to be sealed to separate individual well casing strings from one another in a borehole of a nested monitoring well. The spacers shall be placed at intervals along the casing to ensure a minimum separation of two inches between individual casing strings. Spacers shall be constructed of corrosion-resistant metal, plastic, or other nondegradable material. Wood shall not be used as spacer material.

Any metallic component of a spacer used with metallic casing shall consist of the same material as the casing. Metallic spacer components shall meet the same metallurgical specifications and standards as the casing to reduce the potential for galvanic corrosion of the casing.

The spacing of casing spacers is normally dictated by casing materials used, the orientation and straightness of the borehole, and the method used to install the casing. Spacers shall not be more than 12 inches in length and shall not be placed closer than ten feet apart along a casing string within the interval to be sealed, unless otherwise approved by the enforcement agency.

Casing spacers shall be designed to allow the proper passage of a tremie and distribution of sealing material around casing within the interval to be sealed.

Additional discussion and standards for placement of the annular seal are contained in section 98-55(b)(2), which pertains to sealing the upper annular space, and section 98-55(b)(6), which pertains to sealing-off strata, of the water well standards, and appendix B of bulletin 74-81.

(3) Surface construction features. Additional requirements for surface construction features are in section 98-55(b)(3), which pertains to surface construction features, of the water well standards.

a. Locking cover. The top of a monitoring well shall be protected by a locking cover or equivalent level of protection to prevent unauthorized access.

b. Casing cap. The top of a monitoring well casing shall be fitted with a cap or sanitary seal to prevent surface water, pollutants, or contaminants from entering the well bore. Openings or passages for water level measurement, venting, pump power cables, discharge tubing, and other access shall be protected against entry of surface water, pollutants, and contaminants.

c. Flooding. The top of the well casing shall terminate above ground surface and above the regulatory flood datum (RFD), except where site conditions, such as vehicular traffic, will not allow.

d. Bases. Unless otherwise approved by the enforcement agency, a concrete base or pad shall be constructed around the top of a monitoring well casing at ground surface and contact the annular seal, unless the top of the casing is below ground surface as provided by subsection (b)(3)e of this section, which pertains to vaults. The base shall be at least four inches thick and shall slope to drain away from the well casing. The base shall extend at least two feet laterally in all directions from the outside of the well boring, unless otherwise approved by the enforcement agency.

The base shall be free of cracks, voids, and other significant defects likely to prevent water tightness. Contacts between the base and the annular seal and the base and the well casing must be watertight and must not cause the failure of the well casing or annular seal.

Where cement-based annular sealing material is used, the concrete base shall be poured before the annular seal has set, unless otherwise approved by the enforcement agency.

e. Vaults. At the approval of the enforcement agency, the top of the well casing may be below ground surface because of traffic or other critical considerations. A structurally sound watertight vault, or equivalent feature, shall be installed to house the top of a monitoring well that is below ground surface. The vault shall extend from the top of the annular seal to at least ground surface. In no case shall the top of the annular seal be more than four feet below ground surface.

The casing shall extend at least six inches above the top of the annular seal.

The vault shall contact the annular seal in a manner to form a watertight and structurally sound connection. Contacts between the vault and the annular seal and the vault and the well casing, if any, shall not fail or cause the failure of the well casing or annular seal.

The vault shall be set into or contact the annular seal material before it sets, unless otherwise approved by the enforcement agency.

Cement-based sealing material shall be placed between the outer walls of the vault and the excavation into which it is placed to form a proper, structurally sound foundation for the vault and to seal the space between the vault and excavation.

Sealing material surrounding a vault shall extend from the top of the annular seal to the ground surface. If cement-based sealing material is used for both the annular seal and the space between the excavation and vault, the sealing material shall be placed between the vault and excavation and contact the cement-based annular seal before the annular seal has set.

The vault cover or lid shall be watertight. Any vents shall meet the specifications contained in section 98-55(b)(3)a, which pertains to openings, of the water well standards. The lid shall be fitted with a security device to prevent unauthorized access. The lid shall be clearly and permanently marked "monitoring well." The vault and its lid shall be strong enough to support vehicular traffic where such traffic might occur.

The top of the vault shall be set at or above grade so drainage is away from the vault. The top of the well casing contained within the vault shall be covered in accordance with requirements under subsection (b)(3)a of this section, which pertains to locking cover, and subsection (b)(3)b of this section, which pertains to casing cap, so that water, contaminants, or pollutants that may enter the vault will not enter the well casing.

f. Protection from vehicles. Protective steel posts, or the equivalent, shall be installed around a monitoring well casing where it is terminated above ground surface in areas of vehicular traffic. The posts shall be easily seen and shall protect the well from vehicular impact.

(4) Filter pack. Monitoring well filter pack material shall consist of nonreactive, smooth, rounded, spherical, granular material of highly uniform size and known composition. Filter pack material shall not degrade or consolidate after placement. The grain size of the filter pack shall be matched to the grain size of the aquifer, so that aquifer materials do not enter the filter pack, and the slot size of the screen shall then be matched to the grain size of the filter pack so the filter pack materials do not enter the well.

Filter pack material shall be obtained from clean sources. Filter pack material should be washed and properly packaged for handling, delivery, and storage, if used in monitoring wells constructed for sensitive water quality determinations.

Care should be exercised in the storage of filter pack materials at a drilling site to ensure the material does not come into contact with pollutants or contaminants. Care should also be exercised to prevent the introduction of foreign substances, such as clay or vegetative matter, that might interfere with the placement and function of the filter pack.

Filter pack material shall be placed in the well boring by use of a tremie pipe or equivalent. The depth of the top of the filter pack shall be carefully checked and the volume of emplaced filter pack material verified to determine that filter pack materials have not bridged during installation.

(5) Casing. For the purpose of these standards, the term "casing" applies to screens, collars, risers, and blank casing, and other specialized products used to maintain the well bore. Additional standards for casing materials are contained in section 98-55(b)(5), which pertains to casing, of the water well standards. Special considerations that apply to monitoring well casing are described as follows:

a. Casing material. Casing material shall be in accordance with the following:

1. Chemical compatibility. Special consideration shall be given to the selection of casing materials for monitoring wells installed in environments that are chemically hostile. The selected casing shall resist chemical attack and corrosion.

Special consideration should be given to the selection of casing materials for wells to be used for sensitive water-quality determinations.

2. Plastic and steel casing. Standards for thermoplastic well casing are in section 98-55(b)(5), which pertains to casing, of the water well standards. Fluorocarbon casing materials include fluorinated ethylene propylene (FEP) and polytetra- fluoroethylene (PTFE). Fluorocarbon casing materials shall meet the following specifications, including the latest revisions thereof:

i. ASTM D3296, Standard Specification for FEP-Fluorocarbon Tube.

ii. ASTM D3295, Standard Specifications for PTFE Tubing.

Stainless steel casing shall meet the provisions of ASTM A312, Standard Specification for Seamless and Welded Austenitic Stainless Pipe, and shall meet general requirements for tubular steel products in section 98-55(b)(5), which pertains to casing, of the water well standards.

b. Multiple screens. Monitoring well casing strings shall not have openings in multiple water-bearing units (multilevel monitoring wells), if poor-quality water, pollutants, or contaminants in units penetrated by the well could pass through the openings and move to other units penetrated by the well and degrade groundwater quality, unless otherwise approved by the enforcement agency.

c. Bottom plugs. The bottom of a monitoring well casing shall be plugged or capped to prevent sediment or rock from entering the well.

d. Casing installation. Discussion and standards for the installation of casing materials are in section 98-55(b)(5), which pertains to casing, of the water well standards. Special considerations for monitoring wells are:

1. Cleanliness. Casing, couplings, centralizers, and other components of well casing shall be clean and free of pollutants and contaminants at the time of installation.

2. Joining plastic casing. Plastic casing shall be joined (threaded or otherwise coupled) in a manner that ensures its water tightness. Organic solvent welding cements or glues should not be used for joining plastic casing if glues or cement compounds could interfere with water-quality determinations.

3. Impact. Casing shall not be subjected to significant impact during installation that may damage or weaken the casing.

(6) Well development. Monitoring well development, redevelopment, and reconditioning shall be performed with care so as to prevent damage to the well and any strata surrounding the well that serve to restrict the movement of poor-quality water, pollutants, and contaminants. Development, redevelopment, and reconditioning operations shall be performed with special care where a well has been constructed in an area of known or suspected pollution or contamination.

Water, sediment, and other waste removed from a monitoring well for development operations shall be disposed of in accordance with applicable federal, state, and local requirements. The enforcement agency should be contacted concerning the proper disposal of waste from development operations.

Development methods that may be acceptable under certain circumstances include mechanical surging, overpumping and pump surging, air development, water jetting, and chemical development. The following standards shall be followed where applicable:

a. Mechanical surging. Plungers, bailers, surge blocks, and other surging devices shall incorporate safety valves or vents to prevent excessive pressure differentials that could damage casing or screen.

b. Water jetting. Water used in jetting operations shall be free of pollutants and contaminants.

c. Chemical development. Extreme care shall be exercised in the use of chemicals for monitoring well development. It is often unacceptable to use chemicals for developing monitoring wells to be used for water-quality determinations. Chemicals introduced for development shall be completely removed from the well, filter pack, and water-bearing strata accessed by the well immediately after development operations are completed.

The various methods described in this subsection are sometimes used in combination.

(7) Rehabilitation and repair of monitoring wells. For the purpose of these standards, the term "well rehabilitation" includes the treatment of a well to recover loss in yield caused by incrustation or clogging of the screen, filter pack, and/or water-bearing strata adjoining the well. Well rehabilitation methods that may, in certain cases, be acceptable for monitoring wells include mechanical surging, backwashing or surging by alternately starting or stopping a pump, surging with air, water jetting, sonic cleaning, chemical treatment, or combinations of these.

Rehabilitation methods shall be performed with care to prevent damage to the well and any barriers that serve to restrict the movement of poor-quality water, pollutants, or contaminants. Chemicals used for rehabilitation shall be completely removed from the well, filter pack, and water-bearing strata accessed by the well immediately after rehabilitation operations are completed. Chemicals, water, and other waste shall be disposed of in accordance with applicable federal, state, and local requirements. The enforcement agency should be contacted regarding the proper disposal of waste from rehabilitation operations.

Rehabilitation methods should be compatible with the use of the monitoring well. Special care should be given to the selection of rehabilitation methods for water-quality monitoring wells.

Materials used for repairing well casing shall meet the requirements of section 98-55(b)(5), which pertains to casing, of the water well standards.

(8) Temporary cover. The well or borehole opening and any associated excavations shall be covered at the surface to ensure public safety and to prevent the entry of foreign material, water, contaminants, and pollutants whenever work is interrupted by such events as overnight shutdown, poor weather, and required waiting periods to allow setting of sealing materials and the performance of tests. The cover shall be held in place or weighted down in such a manner that it cannot be removed except by equipment or tools.

During prolonged interruptions (i.e., one week or more), a semipermanent cover shall be installed. For wells cased with steel, a steel cover, tack-welded to the top of the casing, is adequate.

(c) Destruction of monitoring wells. Procedures for the destruction of monitoring wells are as follows:

(1) General requirements. All permanently inactive or abandoned monitoring wells and exploration holes subject to these requirements shall be properly destroyed.

(2) Requirements for destroying monitoring wells and exploration holes. General requirements for destroying monitoring wells and exploration holes are contained in section 98-55(c), which pertains to destruction of wells, of the water well standards. Special considerations for monitoring wells and exploration holes are as follows.

a. Monitoring wells. Monitoring wells shall be destroyed in accordance with the following requirements and section 98-55(c), which pertains to destruction of wells, of the water well standards, irrespective of their original date of construction:

1. The monitoring well casing, and any other significant voids within the well, shall, at a minimum, be completely filled, under pressure, with sealing material, if the following conditions exist:

i. The monitoring well is located in an area of known or potential pollution or contamination; and

ii. The well was constructed and maintained in accordance with these standards.

Casing left in place may require perforation or puncturing to allow proper placement of sealing materials.

2. A monitoring well shall be destroyed by removing all material within the original borehole, including the well casing, filter pack, and annular seal, and the created hole completely filled with appropriate sealing material, if the following conditions exist:

i. The well is located in an area of known or potential pollution or contamination; and

ii. The well's annular seal, casing, screen, filter pack, or other components were not constructed or maintained according to these standards.

3. Monitoring wells shall, at a minimum, be destroyed in accordance with the requirements of section 98-55(c), which pertains to destruction of wells, of the water well standards, if located in an area free of any known or potential contamination or pollution.

b. Exploratory borings. Exploratory borings shall be completely filled with appropriate sealing material from bottom to top.

The boring shall be inspected immediately prior to filling and sealing operations. All obstructions and pollutants and contaminants that could interfere with filling and sealing operations shall be removed prior to filling and sealing. The enforcement agency shall be notified as soon as possible if pollutants or contaminants are known or suspected to be in a boring to be destroyed. Well destruction operations may then proceed only at the approval of the enforcement agency. The enforcement agency should be contacted to determine requirements for proper disposal of removed materials.

c. Placement of material. The placement of sealing material for monitoring wells and exploratory borings is generally described in section 98-55(c), which pertains to destruction of wells, of the water well standards. The following additional requirements shall be observed when placing sealing material for monitoring well or exploratory boring destruction:

1. Placement method. The well or exploratory boring shall be filled with appropriate sealing material using a tremie pipe or equivalent, proceeding upward from the bottom of the well or boring.

Sealing material shall be placed by methods, such as the use of a tremie pipe or equivalent, that prevent freefall, bridging, and dilution of sealing materials, and/or prevent separation of aggregate from sealants. Sealing material may be placed by freefall only where the interval to be sealed is dry and no more than 30 feet in depth.

2. Timing of placement. Sealing material shall be placed in one continuous operation, or "pour," from the bottom to the top of the well or boring, unless conditions in the well or boring dictate that sealing operations be conducted in a staged manner, and prior approval is obtained from the enforcement agency.

3. Groundwater flow. Special care shall be used to restrict the flow of groundwater into a well or boring while placing sealing material, if subsurface pressure producing the flow is significant.

4. Sealing pressure. Pressure required for the placement of cement-based sealing materials shall be maintained long enough for cement-based sealing materials to properly set.

5. Verification. It shall be verified that the volume of sealing material placed during destruction operations equals or exceeds the volume to be sealed.

d. Sealing materials. Materials used for sealing exploratory borings and monitoring wells shall have low permeabilities so that the volume of water and possible pollutants and contaminants passing through them will be of minimal consequence. Sealing material shall be compatible with the chemical environment into which it is placed and shall have mechanical properties consistent with present and future site uses.

Suitable sealing materials include neat cement and sand cement, as described in section 98-55(b)(2), which pertains to sealing the upper annular space, of the water well standards. Drilling mud or drill cuttings are not acceptable as any part of sealing material for well destruction. Concrete may be used as a sealing material at the approval of the enforcement agency.

e. Additional requirements for monitoring wells and exploratory borings in urban areas. The following additional requirements shall be met for destroying monitoring wells and exploratory borings in urban areas, unless otherwise approved by the enforcement agency:

1. The upper surface of the sealing material shall end at a depth of five feet below ground surface; and

2. If the well casing was not extracted during destruction and sealing operations, a hole shall be excavated around the well casing to a depth of five feet below ground surface after sealing operations have been completed and the sealing material has adequately set and cured. The exposed well casing shall then be removed by cutting the casing at the bottom of the excavation. The excavation shall be backfilled with clean, native soil or other suitable material.

f. Temporary cover. The well or borehole opening and any associated excavations shall be covered at the surface to ensure public safety and to prevent the entry of foreign material, water, pollutants, and contaminants whenever work is interrupted by such events as overnight shutdown, poor weather, and required waiting periods to allow setting of sealing materials and the performance of tests. The cover shall be held in place or weighted down in such a manner that it cannot be removed, except by equipment or tools.

During prolonged interruptions (i.e., one week or more), a semipermanent cover shall be installed. For wells cased with steel, a steel cover, tack-welded to the top of the casing, is adequate.

(d) Recovery well pumps. All permanent recovery well pumps shall be constructed and installed so as to provide protection against contamination and pollution of the aquifers. Applicable provisions of section 98-55(d), which pertains to pump standards, of the water well standards, shall be followed.

(Ord. No. 97-01, § 2(6.28.050), 1-2-1997; Ord. No. 97-13, § 2, 3-26-1997; Ord. No. 97-17, § 2, 9-24-1997)

(a) General requirements. General requirements for cathodic protection wells are as follows:

(1) Exemptions due to unusual conditions. Under certain circumstances, the enforcement agency may waive compliance with the standards in this section and prescribe alternate requirements. These standards may be waived only where they are impractical or ineffective because of unusual conditions or would result in unsatisfactory condition or well function. In waiving any of these standards, the enforcement agency shall, if at all possible, require that measures be implemented to provide the same or greater level of water-quality protection that would otherwise be provided by these standards.

(2) Special standards. The enforcement agency may prescribe measures more stringent than standards described in this section, where needed to protect public safety or protect water quality.

(3) Responsible parties. Corrosion control engineers are normally responsible for the design and supervision of corrosion control facilities incorporating cathodic protection wells. Pursuant to Water Code § 13750.5, construction, alteration, and destruction of cathodic protection wells shall be performed by contractors licensed in accordance with the Contractors' State License Law, Business and Professions Code § 7000 et seq., except where exempted by law. Aboveground electrical facilities for cathodic protection wells should be installed by an appropriately licensed contractor.

(b) Cathodic protection well construction. Standards for construction of cathodic protection wells shall be as follows:

(1) Well location with respect to pollutants and contaminants, and structures. The standards contained in section 98-56(b)(1)a, which pertains to separation, section 98-56(b)(1)b, which pertains to flooding and drainage, and section 98-56(b)(1)c, which pertains to accessibility, of the monitoring well standards, shall apply to all cathodic protection wells, unless otherwise approved by the enforcement agency.

(2) Sealing the upper annular space. General discussion of sealing requirements and methods is contained in section 98-55(b)(2), which pertains to sealing the upper annular space, and section 98-55(b)(6), which pertains to sealing-off strata, of the water well standards. Special requirements for sealing cathodic protection wells are as follows:

a. Minimum depth of annular seal. The minimum depth of the annular seal shall be in accordance with the following:

1. Minimum depth. The annular space shall be filled with appropriate sealing material from ground surface to a depth of at least 50 feet below land surface. The annular space shall be sealed to a depth of at least 50 feet below land surface in congested urban areas or where a cathodic protection well is within 100 feet of any potential source of pollution or contamination. Additional annular sealing material shall be installed to greater depths where adverse conditions exist that increase the risk of pollution or contamination of groundwater.

2. Fill. Any annular space existing between the base of the annular surface seal and the top of the anode and conductive fill interval shall be filled with appropriate fill or sealing material. Fill material should consist of washed granular material such as sand, pea gravel, or sealing material. Fill material shall not be subject to decomposition or consolidation after placement and shall be free of pollutants and contaminants. Fill material shall not contain drill cuttings or drilling mud.

3. Sealing-off strata. Additional annular sealing material shall be placed below the minimum depth of the annular surface seal, as needed, to prevent the movement of poor-quality water, pollutants, and contaminants through the well to zones of good quality water. Requirements for sealing off zones are in subsection (b)(5) of this section, which pertains to sealing-off strata.

b. Sealing conditions. Requirements for sealing the annular space under varied conditions are detailed in section 98-55(b)(2)b, which pertains to sealing conditions, of the water well standards.

c. Radial thickness of seal. A minimum of two inches of sealing material shall be maintained between all casings and the borehole wall within the interval to be sealed, except where temporary conductor casing cannot be removed as noted in section 98-55(b)(2), which pertains to sealing the upper annular space, of the water well standards. At least two inches of sealing material shall be maintained between all casings in a borehole, within the interval to be sealed unless otherwise approved by the enforcement agency. Additional space shall be provided, where needed, to allow casings to be properly centralized and spaced and allow the use of a tremie pipe during well construction, if required, especially for deeper wells.

d. Sealing material. Sealing material shall consist of neat cement, sand cement, or concrete, as discussed in section 98-55(b)(2), which pertains to sealing the upper annular space, of the water well standards. Concrete shall only be used at the approval of the enforcement agency. Drill cuttings and used drilling mud shall not be used as any part of sealing material.

e. Placement of seal. Standards for the placement of annular seals are described in section 98-55(b)(2), which pertains to sealing the upper annular space, of the water well standards.

(3) Surface construction features. Surface construction features of a cathodic protection well shall serve to prevent physical damage to the well; prevent the entry of surface water, pollutants, and contaminants; and prevent unauthorized access.

a. Locking cover. The top of a cathodic protection well shall be protected by a locking cover or equivalent level of protection to prevent unauthorized access. All such covers shall allow the venting of gases.

b. Casing cap. The top of a cathodic protection well casing shall be fitted with a watertight cap, cover, U-bend, or equivalent device to prevent the entry of water, pollutants, and contaminants into the well bore. All such covers shall allow venting of gases from the well.

c. Flooding. The top of the well casing shall terminate above ground surface and above the regulatory flood datum (RFD), except where site conditions, such as vehicular traffic, will not allow.

d. Bases. A concrete base or pad shall be constructed around the top of a cathodic protection well casing at ground surface and contact the annular seal, unless the top of the casing is to be below ground surface as provided by subsection (b)(3)e of this section, which pertains to vaults. The base shall be at least four inches thick and shall slope to drain away from the well casing. The base shall extend at least two feet laterally in all directions from the outside of the well boring, unless otherwise approved by the enforcement agency. The base shall be free of cracks, voids, and other significant defects likely to prevent water tightness. Contacts between the base and the annular seal and the base and the well casing must be watertight and must not cause the failure of the well casing or annular seal.

Where cement-based annular sealing material is used, the concrete base shall be poured before the annular seal has set, unless otherwise approved by the enforcement agency.

e. Vaults. At the approval of the enforcement agency, the top of a cathodic protection well may be below ground surface because of traffic or other critical considerations. A watertight, structurally sound vault, or equivalent feature, shall be installed to house the top of the well casing if it terminates below ground surface.

The vault shall extend from the top of the annular seal to at least ground surface. In no case shall the top of the annular seal be more than four feet below ground surface.

The vault shall contact the annular seal in a manner to form a watertight and structurally sound connection. Contacts between the vault and the annular seal, and the vault and the well casing, if any, shall not fail or cause the failure of the well casing or annular seal.

Where cement-based annular sealing materials are used, the vault shall be set into or contact the annular sealing material before it sets, unless otherwise approved by the enforcement agency.

Cement-based sealing material shall be placed between the outer walls of the vault and the excavation into which it is placed to form a proper, structurally sound foundation for the vault and to seal the space between the vault and excavation.

Sealing material surrounding the vault shall extend from the top of the annular seal to ground surface, unless precluded in areas of freezing. If cement-based sealing material is used for both the annular seal and the space between the excavation and vault, the sealing material shall be emplaced between the vault and excavation and contact a cement-based annular seal before the annular seal has set.

The vault cover or lid shall be watertight, and venting of gases is required. Vent openings must be above the regulatory flood datum (RFD) and must meet the specifications contained in section 98-55(b)(3)a, which pertains to openings, of the water well standards. The lid shall be fitted with a security device to prevent unauthorized access and shall be clearly and permanently labeled "cathodic protection well." The vault and its lid shall be strong enough to support vehicular traffic where such traffic might occur.

The top of the vault shall be set at grade, or above, so that drainage is away from the vault. The top of the casing contained within the vault shall be capped in accordance with requirements of subsection (b)(3)b of this section, which pertains to casing cap, so that water, contaminants, and pollutants that may enter the vault will not enter the well casing.

f. Protection from vehicles. Protective steel posts, or the equivalent, shall be installed around a cathodic protection well casing where it is terminated above ground surface in areas of vehicular traffic. The posts shall be easily seen and shall protect the well from vehicular impact.

Additional requirements for surface construction features are contained in section 98-55(b)(3), which pertains to surface construction features, of the water well standards.

(4) Casing. Vent pipe, anode access tubing, and any other tubular materials that pass through the interval to be filled and sealed are all considered casing for the purpose of these standards. Materials used for cathodic protection well casing generally shall meet the requirements for casing materials and their installation in section 98-55(b)(5), which pertains to casing, of the water well standards. Variance from the standards shall be at the approval of the enforcement agency. It is recommended that practices prescribed by the National Association of Corrosion Engineers also be followed in the design and installation of gas vents and electrical conduit.

Cathodic protection well casing should be at least two inches in internal diameter to facilitate eventual well destruction.

(5) Sealing-off strata. If a cathodic protection well penetrates a stratum or strata below the minimum required annular surface seal depth specified in subsection (b)(2)a of this section, which pertains to minimum depth of annular seal, and that stratum contains poor-quality water, pollutants, or contaminants that could mix with and degrade water contained in other strata penetrated by the well, additional annular sealing material shall be placed below the minimum required annular surface seal to prevent mixing and water quality degradation.

The following minimum requirements shall be observed for isolating zones containing poor-quality water, pollutants, or contaminants for various cases:

a. If a stratum containing poor-quality water, pollutants, or contaminants lies above a stratum to be protected, annular seal material shall extend from the top of the stratum containing the poor-quality water, pollutants, or contaminants down to at least ten feet into the confining layer separating the two strata or through the entire thickness of the confining layer, whichever is least.

b. If a stratum containing poor-quality water, pollutants, or contaminants lies below a stratum to be protected, the annular space opposite the stratum to be protected shall be sealed along its full length. The seal shall extend at least ten feet into the confining layer separating the two strata or through the entire thickness of the confining layer, whichever is least.

c. Where two or more strata containing poor-quality water, pollutants, or contaminants are adjacent to one another and overlie a stratum to be protected, the annular space opposite the strata containing poor-quality water, pollutants, or contaminants and opposite all interbedded confining layers shall be sealed. The annular seal shall extend at least ten feet down into, or completely through, whichever is least, the confining layer separating the strata containing poor-quality water, pollutants, or contaminants and the underlying stratum to be protected.

d. Where two or more strata containing poor-quality water, pollutants, or contaminants underlie a stratum to be protected, the annular space opposite the stratum to be protected shall be sealed. The seal shall continue down at least ten feet into, or completely through, whichever is least, the confining layer separating the stratum to be protected and the underlying strata containing poor-quality water, pollutants or contaminants.

e. Where two strata containing poor-quality water, pollutants, or contaminants are separated by a stratum to be protected, the annular space opposite the stratum to be protected, the confining strata underlying and overlying the stratum to be protected, and the upper stratum containing poor-quality water, pollutants, or contaminants shall be sealed off.

The supplementary seals described in the cases in this subsection shall be extended up to and contact the base of the required minimum annular surface seal described in subsection (b)(2)a of this section, which pertains to minimum depth of annular seal, if they are otherwise required to be within ten feet of the surface seal. Sealing the entire annulus above the anode interval will often economically fulfill the conditions outlined in this subsection.

Requirements for sealing materials and their placement are described in subsection (b)(2)a of this section, which pertains to minimum depth of annular seal.

(6) Repair of cathodic protection wells. Materials used for repairing cathodic protection well casing shall meet the requirements of subsection (b)(4) of this section, which pertains to casing.

(7) Temporary cover. The well or borehole opening and any associated excavations shall be covered at the surface to prevent the entry of foreign material, water, pollutants, and contaminants, and to ensure public safety whenever work is interrupted by such events as overnight shutdown, poor weather and required waiting periods to allow setting of sealing materials and the performance of tests. The cover shall be held in place or weighted down in such a manner that it cannot be removed except by equipment or tools.

(c) Destruction of cathodic protection wells. General requirements for well destruction are contained in section 98-55(b), which pertains to destruction of wells, of the water well standards. Special considerations for cathodic protection wells are as follows:

(1) Filling and sealing conditions. Filling and sealing conditions shall be in accordance with the following:

a. Wells that only penetrate unconsolidated material and a single zone of groundwater. At a minimum, the upper 50 feet of the well casing and the annulus between the well casing and borehole wall, if not already sealed, shall be completely sealed with suitable material. Sealing material shall extend to a minimum depth of 50 feet below land surface if the well to be destroyed is located in an urban area or is within 100 feet of any potential source of pollution or contamination. Additional sealing material may be needed if adverse conditions exist. The remainder of the well below the minimum surface seal shall be filled with suitable granular fill material, such as clean sand or pea gravel, or with sealing material.

b. Wells that penetrate several water-bearing strata. The upper portion of the well casing and annular space shall be filled with sealing material as described in subsection (c)(1)a of this section, which pertains to wells that only penetrate unconsolidated material and a single zone of groundwater. Strata encountered below the surface seal that contain poor-quality water, pollutants, or contaminants that could mix with and degrade water in other strata penetrated by the well shall be effectively isolated by sealing the well bore and annulus within intervals specified in subsection (b)(5) of this section, which pertains to sealing-off strata. The remainder of the well shall be filled with suitable granular fill or sealing material.

c. Wells penetrating fractured rock. Sealing material shall be installed as outlined in subsections (c)(1)a and (c)(1)b of this section. Cement-based sealing material shall be used opposite fractured rock. The remainder of the well shall be filled with fill or sealing material, as appropriate.

d. Wells in nonfractured consolidated strata. Sealing material shall be installed as outlined in subsections (c)(1)a and (c)(1)b of this section. The remainder of the well shall be filled with fill or sealing material, as appropriate.

e. Wells penetrating water-bearing zones or aquifers of special significance. The enforcement agency may require that specific water-bearing zones be sealed off for well destruction.

(2) Placement of material. The placement of sealing materials for cathodic protection well destruction is generally described in section 98-55(b), which pertains to destruction of wells, and appendix B of the water well standards. The following additional requirements shall be observed in destroying cathodic protection wells:

Casing, cables, anodes, granular backfill, conductive backfill, and sealing material shall be removed as needed, by redrilling, if necessary, to the point needed to allow proper placement of sealing materials within required sealing intervals. Removal of some or all well materials will likely be required for cathodic protection wells that were not constructed in accordance with these standards or standards adopted by the Southern State Cathodic Protection Committee in December 1969.

Casing that cannot be removed shall be adequately perforated or punctured at specific intervals to allow pressure injection of sealing materials into granular backfill and all other voids that require sealing.

The following requirements shall be observed in placing fill and sealing material in cathodic protection wells to be destroyed:

a. Placement method. The well shall be filled and sealed with appropriate material upward from the bottom of the well using a tremie pipe or equivalent.

Sealing material shall be placed by methods, such as by the use of a tremie pipe or equivalent, that prevent freefall, bridging, or dilution of the sealing materials or separation of aggregates from sealants. Sealing materials shall not be installed by freefall unless the interval to be sealed is dry and no deeper than 30 feet below ground surface.

b. Timing of placement. Sealing material shall be placed in one continuous operation, or "pour," from the bottom to the top of the well unless conditions in the well dictate that sealing operations be conducted in a staged manner and prior approval is obtained from the enforcement agency.

c. Groundwater flow. Special care shall be used to restrict the flow of groundwater into a well while fill and sealing material is being placed, if subsurface pressure causing the flow of water is significant.

d. Sealing pressure. Pressure required for placement of cement-based sealing material shall be maintained long enough for the cement-based sealing material to set.

e. Verification. Verification shall be made that the volume of sealing and fill material placed in a well during destruction operations equals or exceeds the volume to be filled and sealed.

(3) Sealing materials. Materials used for sealing cathodic protection wells for destruction shall have low permeabilities so that the volume of water and possible pollutants and contaminants passing through them will be of minimal consequence. Sealing material shall be compatible with the chemical environment into which it is placed and shall have mechanical properties compatible with present and future site uses.

Suitable sealing materials include neat cement, sand cement, and concrete, as described in section 98-55(b)(2), which pertains to sealing the upper annular space, of the water well standards. Sealing materials used for isolating zones of fractured rock shall be cement-based, as described in subsection (c)(1) of this section, which pertains to filling and sealing conditions. Drilling mud or drill cuttings shall not be used as any part of a sealing material for well destruction. Concrete may be used as a sealing material at the approval of the enforcement agency.

(4) Additional requirements for destruction of cathodic protection wells in urban areas. The following additional requirements shall be met at each well site in urban areas, unless otherwise approved by the enforcement agency:

a. The upper surface of the sealing material shall end at a depth of five feet below ground surface; and

b. If the casing was not extracted during destruction and sealing operations, a hole shall be excavated around the well casing to a depth of five feet below ground surface after sealing operations have been completed and sealing materials have adequately set and cured. The exposed well casing shall then be removed by cutting the casing at the bottom of the excavation. The excavation shall then be backfilled with clean, native soil or other suitable material.

(5) Temporary cover. The well borehole and any associated excavations shall be covered at the surface to prevent the entry of foreign material, water, pollutants, and contaminants and to ensure public safety whenever work on the well is interrupted by such events as overnight shutdown, poor weather, and required waiting periods to allow setting of sealing materials and performance of tests. The cover shall be held in place or weighted down in such a manner that it cannot be removed except by equipment or tools.

(Ord. No. 97-01, § 2(6.28.060), 1-2-1997; Ord. No. 97-13, § 2, 3-26-1997; Ord. No. 97-17, § 2, 9-24-1997)

The enforcement agency shall have the power under the following specified conditions to grant a variance from any of the standards referenced in sections 98-55 through 98-57 and to prescribe alternative requirements in their place:

(1) Special circumstances. The enforcement agency may, under special circumstances, allow a variance from strict interpretation and enforcement of any standard where practical difficulties make it impossible to comply with the standard. Written evidence must be submitted showing that the proposed variance will not impair, contaminate or pollute the groundwater or endanger the health and safety of the public and that strict compliance with this division would be unreasonable in light of all circumstances.

(2) Purpose of division not compromised. The granting of such a variance must be consistent with the purposes of this division.

(Ord. No. 97-01, § 2(6.28.070), 1-2-1997; Ord. No. 97-13, § 2, 3-26-1997; Ord. No. 97-17, § 2, 9-24-1997)

The enforcement agency may designate areas where groundwater quality problems are known to exist and where a well will penetrate more than one aquifer. The enforcement agency may require in these designated areas special well seals to prevent mixing of water from several aquifers. Where an applicant proposes well construction, modification, repair, or destruction work in such an area, the enforcement agency may require the applicant to provide a report prepared by a registered geologist or registered civil engineer (Business and Professions Code §§ 7850 and 6762, respectively) that identifies all strata containing poor-quality water and recommends the location and specifications of the seal needed to prevent the entrance of poor-quality water or its migration into other aquifers.

(Ord. No. 97-01, § 2(6.28.080), 1-2-1997; Ord. No. 97-13, § 2, 3-26-1997; Ord. No. 97-17, § 2, 9-24-1997)

(a) Required. The enforcement agency shall make an inspection of the annular seal construction work performed pursuant to this division. The enforcement agency may also make an initial inspection of each proposed drilling site, an inspection at the completion of the work, and inspections at such other times as it deems appropriate.

(b) Initial inspection. Upon receipt of an application, the enforcement agency may make an inspection of the drilling site prior to the issuance of a well permit. The purpose of this inspection is to determine whether there are any site conditions such that the enforcement agency shall require the following:

(1) Relocation of drilling site. Require relocation of the drilling site should the location shown on the permit application be too close to known or potential sources of pollution or contamination.

(2) Additional conditions. Set additional conditions, if needed to remediate any previously unknown groundwater quality protection problems.

(3) Prohibition of drilling. If the proposed well location will create a hazard or nuisance, drilling will be prohibited.

(c) Inspection of well seal and other operations. The enforcement agency shall inspect the annular space grout depth prior to the sealing of the well. The enforcement agency may also inspect the placement of the well seal, the destruction of a well, or any other operation necessary to fulfill the provisions of the permit or this division.

(1) Required notice. The enforcement agency shall be notified by the applicant, during normal business hours, a minimum of 48 hours prior to seal placement, well destruction, or completion of other operations imposed by special permit conditions. These inspections shall be scheduled to be conducted during normal business hours, unless otherwise negotiated.

(2) Enforcement agency's failure to be present. No grout seal shall be placed until permission to proceed is given by the enforcement agency. The enforcement agency may allow a grout seal to be placed in its absence provided that the placement of the seal is performed under the supervision of a state-registered geologist, a state-registered professional engineer in the appropriate discipline as defined by Business and Professions Code §§ 7803 and 6701, respectively, a state-registered environmental health specialist, or a certified engineering geologist who submits, within 30 days from the date of sealing, a statement, signed under penalty of perjury, detailing the seal depth, thickness, material and method of placement.

(d) Final inspection and well completion. Final inspection and well completion shall be in accordance with the following:

(1) The applicant shall notify the enforcement agency within five working days of the completion of the work so that the enforcement agency may make a final inspection to determine whether the work was completed in accordance with this division. No applicant shall be deemed to have complied with this division until such inspection has been performed.

(2) Upon completion of the drilling process, the applicant shall be responsible for placement of the casing, grouting of the annular space, and either the installation of a pump or the securing of a watertight cap or plug on the casing.

(3) No well shall be placed into use until final approval is granted by the enforcement agency. This shall not apply to monitoring wells.

(Ord. No. 97-01, § 2(6.28.090), 1-2-1997; Ord. No. 97-13, § 2, 3-26-1997; Ord. No. 97-17, § 2, 9-24-1997)

(a) If the deputy, with reasonable cause, believes that a well is causing a nuisance or that a violation of this division has occurred, the deputy may investigate the situation to determine whether such a nuisance or violation does in fact exist. The deputy shall have the power, as described in this section, to enter the premises to inspect for any violation or condition that may cause or constitute a nuisance. The deputy is authorized to collect samples and perform testing as needed, and the deputy may take any other steps reasonably necessary for determination of whether a violation or nuisance exists.

(b) If any such premises are occupied, the deputy shall first present proper credentials and request entry.

(c) If the premises are unoccupied, the deputy shall, prior to entering the property, make a reasonable effort to locate the owner or other person having charge or control of the premises and request entry. If no person is found in control of the property, the deputy may enter the property.

(d) If such entry is refused, the deputy shall have recourse to such remedies as are provided by law to secure entry.

(Ord. No. 97-01, § 2(6.28.100), 1-2-1997; Ord. No. 97-13, § 2, 3-26-1997; Ord. No. 97-17, § 2, 9-24-1997)

(a) Submittal of state well completion report. A copy of the well completion report (Water Well Driller's Report, Department of Water Resources Form 188) required by Water Code § 13751 shall be submitted by the applicant to the enforcement agency within 30 days of construction, modification, repair, or destruction of any well. This report shall document that the work was completed in accordance with the standards in this division and all additional permit conditions. This section shall not be deemed to release any person from the requirement to file such report with the department of water resources.

(b) Confidentiality of report. In accordance with Water Code § 13752, reports shall not be made available for inspection by the public but shall be made available for inspection by governmental agencies for use in making studies. Reports shall be made available to any person who obtains written authorization from the owner of the well.

(c) Other requirements. Nothing in this division shall be deemed to excuse any person from compliance with Water Code §§ 13750—13755 relating to notices and reports of completion or any other federal, state, or local reporting regulations.

(Ord. No. 97-01, § 2(6.28.110), 1-2-1997; Ord. No. 97-13, § 2, 3-26-1997; Ord. No. 97-17, § 2, 9-24-1997)

(a) Criminal enforcement. Criminal enforcement of this division shall be in accordance with the following:

(1) Infractions. Notwithstanding section 1-21, a violation of any of the sections of this division, or failure to comply with any of the regulatory requirements of this division, is an infraction or a misdemeanor as set forth in subsection (a)(3) of this section, subject to the procedures described in Penal Code §§ 19.6 and 19.7.

(2) Penalty for infraction. Unless otherwise specified by this division, an infraction is punishable by the following:

a. A fine not exceeding $100.00 for a first violation;

b. A fine not exceeding $200.00 for a second violation of the same section of this division within one year; and

c. A fine not exceeding $500.00 for each additional violation of the same section of this division within one year.

(3) Elevation to misdemeanor. Any offense which would otherwise be an infraction is a misdemeanor if the defendant has been convicted of the same offense three or more times within the 12-month period immediately preceding the commission of the offense and such convictions are alleged in the accusatory pleadings. For this purpose, a bail forfeiture shall be deemed to be a conviction of the offense charged.

(4) Penalty for misdemeanor. Unless otherwise specified by this division, a misdemeanor is punishable by a fine not exceeding $1,000.00, imprisonment for a term not exceeding six months, or by both such fine and imprisonment.

(b) Civil enforcement. Civil enforcement shall be in accordance with the following:

(1) Violations. Violation of any of the sections of this division may in the alternative be remedied through civil action filed in a court of competent jurisdiction for injunctive relief or other appropriate remedy.

(2) Nuisance. Whenever the deputy determines that a nuisance exists, the deputy may take action to abate the nuisance.

(c) Continuing violation. Each and every day a violation of this division continues shall constitute a separate offense. The person committing or permitting such offenses may be charged with a separate offense for each such violation and punished accordingly.

(d) Remedies cumulative. The remedies available to enforce this division are in addition to any other remedies available under ordinance or statute and do not replace or supplant any other remedy but are cumulative thereto.

(Ord. No. 97-01, § 2(6.28.120), 1-2-1997; Ord. No. 97-13, § 2, 3-26-1997; Ord. No. 97-17, § 2, 9-24-1997)

(a) Generally. Under this division, any person whose application for a permit has been denied or granted conditionally or whose variance request has been denied may make an appeal to the hearing officer. Any such appeal shall be in writing, shall state the specific reasons therefor and grounds asserted for relief, and shall be filed with the deputy not later than 15 days after the date of service of the notice of denial. If an appeal is not filed within the time or in the manner prescribed in this subsection, the right to review of the action against which complaint is made shall be deemed to have been waived.

At the time of filing, the appeal and as a condition precedent to the legal effectiveness of the appeal, the appellant shall pay an appeal filing fee, in the amount specified by section 6.99.095 of the Sacramento County Code.

(b) Appeal hearing. Not later than 30 days following the date of filing an appeal within the time and in the manner prescribed in subsection (a) of this section, the hearing officer shall conduct a hearing for the purpose of determining whether the appeal should be granted. Written notice of the time, date, and place of the hearing shall be mailed to the appellant not fewer than ten days preceding the date of the hearing.

During the hearing, the burden of proof shall rest with the appellant. The provisions of the State Administrative Procedure Act, Government Code § 11500 et seq., shall not be applicable to such hearing, nor shall formal rules of evidence in civil or criminal judicial proceedings be so applicable. At the conclusion of the hearing, the hearing officer shall prepare a written decision which either grants or conditionally grants or denies the appeal and contains findings of fact and conclusions. Notice of the written decision, including a copy thereof, shall be filed with the deputy and mailed to the appellant not later than ten days following the date on which the hearing is closed. The decision by the hearing officer shall become final upon the date of filing and mailing.

(c) Hearing officer. The city manager shall be authorized to assign hearing responsibilities from time to time to either:

(1) Management personnel whom the city manager finds are qualified by training and experience to conduct such hearings;

(2) Any person, qualified by training or experience, who the city manager may employ or who is retained by contract to conduct such hearings; or

(3) Administrative law judges assigned to the state office of administrative hearings.

The city manager is hereby authorized to contract in the name of the city for the retention of hearing services at rates which do not exceed the financial limitations established by the city's annual budget.

(d) Continuances. The hearing may be delayed once for a period of time, not to exceed 30 days, to allow the appellant additional time to prepare for the hearing.

(e) Appeal to the council. An appeal, if any, of the final decision of the hearing officer must be made within 30 days to the city council.

(Ord. No. 97-01, § 2(6.28.130), 1-2-1997; Ord. No. 97-13, § 2, 3-26-1997; Ord. No. 97-17, § 2, 9-24-1997)

Pursuant to Water Code § 13225(c), the enforcement agency shall submit a report, not less than annually, to the California Regional Water Quality Control Board, Central Valley Region, which has jurisdiction in the county. This report shall contain the following data, unless the regional board determines a lesser amount of information is necessary:

(1) Wells constructed or destroyed. The number of wells constructed or destroyed.

(2) Abatement actions. Descriptions of all well destructions undertaken by the enforcement agency using its regulatory authority under nuisance abatement powers.

(3) Variances granted. A description of each specific case where variances were granted and the circumstances that made a variance necessary.

(4) Grout placement inspections by nonenforcement agency personnel. A description of each specific case where an inspection of the placement of the annular seal was conducted by nonenforcement agency personnel and the circumstances that made this action necessary.

(Ord. No. 97-01, § 2(6.28.140), 1-2-1997; Ord. No. 97-13, § 2, 3-26-1997; Ord. No. 97-17, § 2, 9-24-1997)