Fresno County Municipal Code Ch. 14.08 Well Construction, Pump Installation and Well Destruction Standards

A. All wells shall be located a safe horizontal distance from potential sources of contamination and pollution, as determined by the health officer. The following horizontal distances are presumed to be safe, in the absence of specific information to the contrary, where dry upper unconsolidated formations less permeable than sand are encountered:

* If the well is a radial collector well, these distances apply to the furthest extended points of the well.

** Community wells with an annular seal of less than fifty feet in depth shall be located at least two hundred fifty feet from any source of potential contamination.

Because of the many variables involved in the determination of the safe horizontal distance of a well from potential sources of contamination and pollution, no one set of distances will be adequate and reasonable for all conditions. In areas where adverse conditions exist, the distances listed should be increased. Conversely, where especially favorable conditions exist or where special means of protection, particularly in construction of the well are provided, lesser distances may be acceptable if approved by the Environmental Health System.

B. If possible, the well shall be located upstream of the groundwater gradient from potential sources of contamination.

C. The top of the casing shall be extended a minimum of six inches above ground level to prevent flooding by drainage or runoff from the surrounding land.

D. A well near a building shall be far enough from the building to be accessible for repair and maintenance.

E. All pump discharge pipes not discharging to the atmosphere shall be equipped with an approved check valve to prevent backflow or back-siphonage into the well when the pump shuts down. The check valve shall be installed between the pump head and the connection to the distribution system or standpipe.

(Ord. 0-83-008, § 5; Ord. 470-A-39, § 2, 1974)

The space between the well casing and the wall of the drilled hole (the annular space) shall be effectively sealed as determined by the health officer to protect against contamination or pollution by surface or shallow subsurface waters. The following minimum standards of construction shall be presumed to be adequate in the absence of specific information necessitating a higher standard.

A. Depth of Seal. Following is the minimum depth of seal below ground surface for various uses of wells.

* Exceptions are shallow wells where the water to be developed is at a depth less than twenty feet. In this instance, the depth of seal may be reduced but in no case less than ten feet and special precautions shall be taken in locating the well with respect to possible sources of contamination.

B. Sealing Conditions. The following requirements shall be met in sealing the annular space:

1. Wells Drilled Unconsolidated Caving Material.

a. For a cable-tool well, the outer casing (conductor casing), may function as the seal provided the length of the conductor casing corresponds to the depth of seal specified in subsection A of this section.

b. For a rotary well, the annular space shall be filled with sealing material to the depth specified in subsection A of this section. When a temporary conductor casing is used to hold out the caving material during placement of the seal, it may be left in place or withdrawn as the sealing material is placed. (See Figure 1.)

2. Wells That Penetrate Stratified Formations. Where a clay stratum can be encountered within five feet of where the bottom of the seal described in subsection A of this section would terminate, the seal shall be extended into the clay. (See Figure 1.)

3. Gravel Packed Wells. In gravel packed wells constructed without a conductor casing, the gravel pack shall terminate at the base of the seal. Gravel fill pipes may be installed in the seal. In wells constructed with a conductor casing (which allows the gravel pack to extend to the top of the well), the annular space between the conductor casing and the wall of the drilled hole shall be sealed to the depth specified in this section. (See Figure 1)

4. Wells in Consolidated Rock. A two-inch over-sized hole shall be constructed to the depth and diameter required for the seal and casing installed to retain the seal. (See Figure 1.)

5. Convert wells. Wells which are converted to community wells, particularly those constructed in prior years without annular seals, shall have annular seals installed to the depth specified for community water supply wells as required in subsection A and at the thickness described in subsection E, both of this section. Wells converted to domestic wells must have a concrete surface pad.

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 Section 14.08.050.

D. Sealing Material. The sealing material shall consist of neat cement, cement grout, bentonite clay or concrete.

E. Thickness of Seal. The thickness of the seal shall be not less than two inches, except as indicated in Section 14.08.020B4 and not less than three times the size of the largest course aggregate used in the sealing material except where equivalent protection is provided in a manner approved by the health officer.

F. Placement of Seal. The sealing material shall be applied, if possible, in one continuous operation from the bottom of the interval to be sealed to the top. If the annular seal depth is beyond twenty feet (6 meters) a tremie or grout pipe shall be used to deliver sealing material from the bottom of the annular space to the top.

[Figure]

(Ord. 0-83-008, § 6; Ord. 470-A-39, § 2, 1974)

A. Openings. Openings into the top of the well shall be sealed except openings designed to provide access to agricultural wells. All wells shall have an opening from the surface into the casing of sufficient diameter as determined by the health officer which will permit measurement of water depth or the addition of gravel. Such openings shall be protected against the entrance of surface waters by the installation of watertight caps and against entrance of foreign matter by the installation of caps, plugs, screens, or downturned U bends.

1. Except for agricultural wells, where the pump is installed directly over the casing, an annular watertight seal gasket shall be placed between the pump head and the pump base (slab), or a watertight seal gasket shall be placed between the pump base and the rim of the casing, or a seal or "well cap" shall be installed to close the annular opening between the casing and the pump column pipe.

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.

3. All holes in the base of the pump which open into the well shall be sealed on all domestic, industrial and commercial wells.

4. If the pump is not installed immediately upon completion of the well or if there is a prolonged interruption in construction of the well, a watertight cap shall be provided at the top of the casing.

5. Pump discharge piping shall be located above the ground where possible; however, in the event of a below-ground discharge (below pump base), there shall be a watertight seal or gasket between the discharge pipe and well casing.

6. A concrete surface slab shall be constructed around the top of the casing on all domestic water supply wells, and it shall be free from cracks or other defects likely to detract from its watertightness. The slab shall be monolithically poured on thoroughly compacted earth and shall have a minimum thickness of four inches for individual domestic systems. The slab shall be extended at least two feet in all directions from the casing and four feet or more in one direction if the storage tank is to be at the well location. The slab shall be graded away from the casing in all directions at a fall of at least one-fourth inch per foot.

7. Where the well is to be gravel packed, a watertight cover shall be installed between the conductor pipe and the inner casing at the top of the well.

B. Well Pits. Because of their susceptibility to contamination and pollution, well pits shall be permitted only upon approval of the health officer. When a pit is authorized, the following requirements shall be observed:

1. The bottom of the pit shall not extend below the water table.

2. The casing shall extend at least six inches above the pit floor.

3. The pit shall be constructed and protected so that rain, flood or seepage waters cannot enter it.

4. The pit shall be provided with a drainage sump and an automatic sump pump (or, if topography permits, a "gravity" discharge). The discharge pipe from the sump shall not be connected to any sewer or pipe drain. The outlet of the discharge pipe shall be above ground level, above known conditions of flooding and protected against entry of small animals.

5. The top of the pit shall be provided with a watertight cover such as a concrete slab, metal cover or house of equivalent watertight construction.

6. Each pit shall have easy access for proper operation, maintenance and inspection of the equipment, and shall have a locked door or hatch to insure the public safety.

7. The pump air vent pipe and the casing vent shall be installed above the flood level and opening shall be screened.

C. Enclosure of Well and Appurtenances. For community water supply wells, the well and pump shall be located in a locked enclosure a minimum of six feet in height to exclude access by unathorized persons.

D. Pump Blow-Off. When there is any blow-off or drainage from the pump, it shall be so located that there is no hazard to the safety of the water supply by reason of flooding, back siphonage or back pressure. The blow-off or drainage shall not be connected to any sewer.

E. Air Vents. In community water supply wells a casing vent and an air release vent shall be installed.

(Ord. 0-83-008, § 7; Ord. 470-A-39-a1, § 1, 1975; Ord. 470-A-39, § 2, 1974)

A. Disinfection. All community water supply, individual domestic, and industrial wells shall be disinfected following construction, repair or when work is done on the pump, before the well is placed in service.

B. Gravel. Gravel used in gravel-packed wells shall came from clean sources and, except for agricultural wells, shall be thoroughly washed before being placed in the well. Gravel purchased from a supplier shall be washed at the pit or plant prior to delivery to the well site. Gravel shall be treated with hypochlorite tablets at time of well construction.

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.

(Ord. 0-83-008, § 8; Ord. 470-A-39, § 2, 1974)

In areas where a well penetrates more than one water bearing stratum and any of the stratum contains water of a quality such that, if allowed to mix with water of another stratum, will in the judgment of the health officer result in a significant deterioration, the stratum producing such inferior water shall be sealed off to prevent entrance of the water into the well or its vertical migration to other strata.

A. The undesirable water bearing stratum shall be sealed off by placing impervious material opposite the stratum and opposite the confining bed for a sufficient vertical distance (but not less than ten feet) in either direction to prevent the vertical movement of water from the producing formation. Sufficient sealing material shall be applied to fill the annular space between the casing and the wall of the drilled hole in the interval to be sealed, and to fill the voids which might absorb the sealing material.

B. Sealing material shall consist of neat cement, cement grout, or other suitable impervious material (Section 14.08.160-E-1).

C. Sealing shall be accomplished by a method approved by the health officer.

D. In areas of Fresno County underlain by Corcoran Clay, wells which extend through this clay shall not be perforated both above and below the clay except in the following instances:

1. Where the Corcoran Clay is less than twenty feet in thickness;

2. In areas where the difference in water quality above and below the clay is approximately seven hundred micromhos (five hundred ppm TDS) or less;

3. In the area east of the Fresno Slough and south of the Murphy Slough.

E. In all wells which penetrate the Corcoran Clay, the following regulations shall apply:

1. A spontaneous potential and electrical resistivity log shall be made for the entire depth of the well, except for cable tool constructed wells. The log and a written analysis shall be immediately made available to the health officer. For rotary drilled wells where there is an indication from the E log that the water in a water bearing stratum exceeds a value of three thousand five hundred micromhos, the casing in such areas shall not be perforated.

2. In cable tool wells, a measurement of the electrical conductivity (at twenty-five degrees centigrade) of the bailed water shall be made and recorded at thirty for intervals of well depth throughout construction. If separate unsampled water bearing strata are identified during construction, the electrical conductivity of bailed water for that water bearing strata shall be measured. If the electrical conductivity of the water in a water bearing stratum exceeds a value of three thousand five hundred micromhos, the casing in such areas shall not be perforated. All electrical conductivity measurements shall be submitted to the health officer.

3. Wells which penetrate the clay shall be constructed with provisions which allow for the vertical movement of the casing without casing collapse. Such provisions may include a slip joint or a weak point in the casing.

4. Well casing shall not be perforated opposite the Corcoran Clay nor shall gravel a placed opposite the clay.

F. On new or reconstructed wells which are perforated above and/or below the Corcoran Clay, the following monitoring criteria shall be followed:

1. Within ninety days after the well is placed into use, and after seven days of continuous pumping, a complete chemical analysis, including electrical conductivity, and a water temperature determination shall be made and the results submitted to the health officer.

G. Wells which penetrate perched waters shall meet the following requirements:

1. Perched waters, including those retained on the A Clay, shall be excluded from all wells except when the well is drilled expressly for the extraction of perched waters for ground water level control, or water quality control, or where it can be demonstrated that the transfer of such water will not in the judgment of the health officer cause a significant deterioration of the quality of water in underlying water strata.

2. Wells drilled for extraction of perched waters for ground water level control or for water quality control shall not penetrate any usable ground water body lying below the perched water.

3. In rotary type wells penetrating the A Clay, a positive seal at least twenty feet or at least the thickness of the A Clay shall be provided in the annular space of each well.

(Ord. 470-A-39, § 2, 1974)

Developing, redeveloping or conditioning of a well shall be done with care and by methods which will not cause damage to the well or cause adverse subsurface conditions that may destroy barriers to the vertical movement of water between aquifers. The following methods used in developing, redeveloping or conditioning a well when done with care are acceptable:

A. Overpumping;

B. Surging by use of a plunger or compressed air;

C. Backwashing or surging by alternately starting and stopping the pump, pouring water in the well or jetting with water;

D. Introduction of chemicals designed for this purpose; and

E. A combination of the above. Methods which produce an explosion are not prohibited; however, they should be used with care, particularly where two or more distinct aquifers have been penetrated. Where chemicals or explosives have been used, the well shall be pumped until all traces of these agents have been removed.

(Ord. 470-A-39, § 2, 1974)

The requirements to be met with respect to water quality sampling are as follows:

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 shall be made. Approval of the health officer shall be obtained before the well is used.

1. Sample Tap. A sample tap shall be provided on the discharge line beyond the check valve so that water representative of the water in the well may be drawn for laboratory analysis.

2. Laboratory Analysis. The appropriate analysis shall be performed by the Fresno County department of health or by a laboratory certified by the California Department of Health. A copy of the laboratory analysis shall be forwarded to the health officer.

3. Bacterial Quality. Where the water is to be used for domestic purposes, samples shall be collected for bacteriological analysis after all traces of development and disinfectant chemicals have been removed from the well.

4. Chemical (Mineral) Quality. Where the water is to be used for domestic purposes or for food processing, samples shall be collected and a chemical analysis made.

B. Individual Domestic Wells.

1. The water from an individual domestic well may be sampled by the health officer for bacteriological analysis after all traces of development or disinfectant chemicals have been removed from the well.

2. A determination may be made by the health officer of the mineral quality of the water produced by such wells.

(Ord. 470-A-39, § 2, 1974)

A. Use as Community Water Supply Wells. The use of bored or dug wells, or wells less than fifty feet deep, to provide community water supplies shall be avoided unless in the opinion of the health officer there is no other feasible means for obtaining water. When used for this purpose, these wells shall be located at least two hundred fifty feet from any underground sewage disposal facility.

B. Bored Wells. All bored wells shall be cased with concrete pipe or steel casing whose joints are watertight from six inches above surface to the depths specified in Section 14.08.020. The space between the wall of the hole and the casing shall be filled with concrete to the depths specified in said section. The minimum thickness of the surrounding concrete seal shall be three inches.

C. Dug Wells. All dug wells shall be curbed with a watertight curbing extending from the surface to the depths specified in Section 14.08.020. The curbing shall be of concrete poured-in-place or of casing, either 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 depths specified in Section 14.08.020. The minimum thickness of the surrounding concrete shall be four inches.

D. Casing Material. Either steel or concrete shall be used for casing bored or dug wells.

1. Steel used in the manufacture of casing for bored and dug wells shall conform to the specifications for casing material described in Section 14.08.050. The minimum thickness of steel casing for dug wells shall be in accordance with the following table:

Minimum Thickness of Steel Casing for Bored and Dug Wells

2. Concrete casing can consist of either poured-in-place concrete or precast concrete pipe. Poured-in-place concrete shall be sufficiently strong to withstand the earth and water pressure imposed on it. It shall be reinforced with steel to furnish tensile strength and to resist cracking, and it shall be free from honeycombing or other defects likely to impair the ability of the concrete structure to remain watertight. Aggregate small enough to insure proper placement without bridging shall be used.

Precast concrete pipe shall be composed of concrete rings from one to six feet in diameter and approximately three to eight feet long, and shall be free of any blemishes that would impair their strength or service ability. In the portion of the well that is to be sealed (see subsections B and C of this section), the joints shall be made watertight. Concrete pipe shall conform to the specifications listed in Section 14.08.050.

E. Covers. Every bored and dug well shall be provided with a structurally sound, watertight cover made of concrete or steel.

(Ord. 0-83-008, § 10; Ord. 470-A-39, § 2, 1974)

A. If a driven well is to be used as an individual domestic well, an oversize hole with a 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, cement grout or a bentonite mud.

B. The minimum wall thickness of steel drive pipe shall be not less than 0.140 inches.

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

(Ord. 0-83-008 11; Ord. 470-A-39, § 2, 1974)

A. All casing used in the deepening or repair of wells shall meet the requirements of Section 14.08.050.

B. If the old casing is removed, the well shall be recased and sealed in accordance with the requirements of Section 14.08.050.

(Ord. 470-A-39, § 2, 1974)

A. Whenever there is an interruption in work on the well (i.e., overnight shutdown during inclement weather, or waiting periods required for the setting up of sealing materials, testing or the installation of the pump), the well opening shall be closed with a cover to prevent the introduction of undesirable material into the well and to protect the public safety.

B. During interruptions of 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 permitted.

C. Observation and monitoring wells must meet all standards with exception of the cement surface pad requirement.

(Ord. 0-83-008, § 12; Ord. 470-A-39, § 2, 1974)

The board of supervisors declares and finds that abandoned wells must be destroyed as hereinafter provided in this chapter to promote and protect the public welfare as follows:

A. To prevent the pollution of the groundwater; and

B. To prevent physical injury to persons or damage to property.

(Ord. 470-A-39, § 2, 1974)

A well is considered "abandoned" when it has not been used for a period of one year, unless the owner declares his intention to use the well again for supplying water or other associated purpose (such as an observation well or injection well). As evidence of his intentions for continued use, the owner shall maintain the well in such a way that:

A. The well has no defects which will facilitate the impairment of quality of water in the well or in the waterbearing formations penetrated;

B. The well is covered with a locked watertight cap or other secured means;

C. The well is marked so that it can be clearly seen;

D. The area surrounding the well is kept clear of brush or debris;

E. An abandoned well shall not be used for the disposal of any liquid or solid waste.

If the pump has been removed for repair or replacement, the well shall not be considered abandoned, provided that evidence of repair can be shown. During the repair period, the well shall be adequately covered to prevent injury to people and to prevent the entrance of undesirable water or foreign matter. Observation or test wells used in the investigation or management of groundwater basins by governmental agencies or other appropriate engineering or research organizations are not considered abandoned so long as they are maintained for this purpose. However, such wells shall be covered with an appropriate cap, bearing the label, "Observation Well," and the name of the agency or organization. When these wells are no longer used for this purpose or for supplying water, they shall be considered abandoned.

(Ord. 0-83-008, § 13; Ord. 470-A-39, § 2, 1974)

All abandoned wells shall be destroyed in such a way that they will not produce water or act as a channel for the interchange of waters, when such interchange will, in the judgment of the health officer, result in significant deterioration of the quality of water in any or all water-bearing formations penetrated, or present a hazard to the safety and well being of people or animals.

Destruction of a well shall consist of the complete filling of the well in accordance with the procedures described in Section 14.08.160.

(Ord. 470-A-39, § 2, 1974)

A. Objective. The objective of the requirements described in this section is to maintain or, if practicable, to restore as nearly as feasible those subsurface conditions affecting movement of water which existed before the well was constructed, also taking into account changes, if any, which have occurred since the time of well construction.

B. Preliminary Work. Before the hole is filed, the well shall be investigated to determine its condition, details of construction and whether there are obstructions that will interfere with the process of filling and sealing.

1. If there are any obstructions, they shall be removed if in the judgment of the health officer it is economically feasible.

2. In dug wells, as much of the lining as possible shall be removed prior to filling.

C. Filling and Sealing Conditions. Abandoned wells of the type or condition hereinafter designated shall be filled or sealed as follows:

1. Well wholly situated in unconsolidated material in an unconfined groundwater zone. If the groundwater supplies are within fifty feet of the surface, the upper twenty feet shall be sealed with impervious material and the remainder of the well shall be filled with clay, sand or other suitable inorganic material.

2. Well penetrating several distinct groundwater zones. In all cases, the upper twenty feet of the well shall be sealed with impervious material. In areas where the interchange of water between aquifers will in the judgment of the health officer result in a significant deterioration of the quality of water in one or more aquifers, or in areas where the well penetrates the Corcoran Clay except as indicated in Section 14.08.060(D)(1), (2) or (3), 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 aquifer where impervious sealing material is not required. Impervious material shall be placed opposite confining formations for a sufficient vertical distance (but in no case less than ten feet) in either direction to prevent the vertical movement of water from the producing formation. 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 either direction or, in the case of bottom waters, in the upward direction. In locations where interchange is in no way detrimental, suitable inorganic material shall be placed opposite the formations penetrated.

3. Well penetrating fractured rock. If fractured rock formations are encountered immediately below the surface, the portions of the well opposite this formation shall be sealed with neat cement, cement grout or concrete. When authorized by the health officer, alternate layers of coarse stone and cement grout or concrete may be used to fill the well when these formations extend to a sufficient depth to safely permit its use. Fine grained material shall not be used as fill material for creviced or fractured rock formations.

4. Well in nonfractured, consolidated formation. The upper twenty feet of a well in a nonfractured, consolidated formation shall be filled with impervious material. The remainder of the well may be filled with clay or other suitable inorganic material.

5. Well penetrating specific aquifers, local conditions. Under certain local conditions, the health officer shall require that specific aquifers or formations be sealed off during destruction of the well when he determines that the chemical composition of the water may degrade other groundwater.

D. Placement of Material. The following requirements shall be observed in placing fill or sealing material in wells to be destroyed:

1. The well shall be filled with the appropriate material (as described in subsection E of this section).

2. Where neat cement, cement grout or concrete is used, it shall be poured in one continuous operation.

3. Sealing material shall be placed in the interval or intervals to be sealed by methods that prevent free fall, dilution or separation of aggregates from cementing materials except as amended in subsection 5.

4. To assure that the well is filled and that there has been no jamming or "bridging" of the material, verification shall be made that the volume of material placed in the well installation at least equals the volume of the empty hole.

5. Providing that the conditions imposed in subsections 1 and 4 above are fully met, these standards shall not preclude the backfilling of abandoned well casings with a mixture of water and fine grain inorganic material, introduced in the upper elevation of the casing.

6. Wells to be destroyed which penetrate through Corcoran Clay shall be sealed for the entire thickness of this clay member. Casing above the Corcoran Clay may be backfilled, using the procedure permitted in subsection 5 above.

7. Wells to be destroyed which penetrate through the A Clay shall be effectively sealed for the entire thickness of the clay member. Casing above and below the A Clay may be backfilled, using the procedure permitted in subsection 5 above.

8. Open bottom agricultural wells not in excess of four hundred feet in depth which are wholly situated in unconsolidated material in an unconfined groundwater zone may be sealed at a depth of fifty feet, and the upper part of the casing filled in the manner described in subsection 5 above to an elevation of six feet below ground level, at which point the casing shall be cut and removed, and the balance of the hole filled with native soil.

9. Wells located on land that is being subdivided shall be identified on the tentative subdivision map. Prior to the recording of the final map, all such wells shall either be brought into compliance with these standards or be destroyed.

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

1. Sealing Materials. Suitable materials include neat cement, cement grout, concrete, bentonite clay (muds), silt and clays, well proportioned mixes of silts, sands and clays (or cement), and native soils and natural material that have a coefficient of permeability of less than ten feet per year. Used drilling muds are not acceptable.

A neat cement mixture shall be composed of one bag of Portland cement to five to seven gallons of clean water. Cement grout shall be composed of not more than two parts of sand and one part of cement (per bag of cement) to five to seven gallons of clean water. Concrete used shall be class A (six sacks of Portland cement per cubic yard) or class B (five sacks per cubic yard).

2. Fill Material. The following materials are suitable for use as a filler in destroying wells: Clay, silt, sand, gravel, crushed stone, native soils, mixture of the aforementioned types and those described in the preceding paragraph. Organic matter shall not be used.

F. Additional Requirements for Wells in Urban Areas. In urban areas zoned for residential uses, the following additional requirements must be met:

1. A hole shall be excavated around the well casing to a depth of six feet below the ground surface and the well casing removed to within six inches of the bottom of the excavation.

2. The sealing material used for the upper portion of the well shall be allowed to spill over into the excavation to form a cap at least one foot thick.

3. After the well has been properly filled, including sufficient time for sealing material in the excavation to set, the excavation shall be filled with native soil.

G. 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 strong and well enough anchored to prevent the introduction of foreign material into the well and to protect the public from a hazardous situation.

(Ord. 0-83-008, § 14; Ord. 470-A-39, § 2, 1974)

All cathodic protection wells shall be constructed in accordance with the cathodic protection well standards adopted by the Department of Water Resources and set forth in Bulletin No. 74-1 entitled "Cathodic Protection Well Standards," dated March 1973, which standards are incorporated herein by reference.

(Ord. 470-A-39, § 2, 1974)