Tehama Municipal Code Art. I General Provisions

It is the intent of this chapter to protect the health, safety and general welfare of the people of Tehama County by providing minimum procedures for the proper construction, reconstruction, repair and destruction of wells so that wells constructed or abandoned pursuant to this chapter will not cause the quality of groundwaters within Tehama County to become impaired or polluted. It is also the purpose of this chapter to recognize and define requirements for monitoring well(s) used in environment assessments and site mitigation.

(Ord. 1707 § 1(part), 1999)

The following terms are defined as used in this section:

"Abandoned well" shall mean a well which has not been used for one year or which is not being properly maintained. For purposes of this definition, "proper maintenance" shall include but not be limited to the prevention of conditions which could impair the quality of water in the well or in the water-bearing formations penetrated. A properly maintained out-of-service well shall not be considered to be an abandoned well. "Abandoned wells" shall include a well drilled to secure water but which is a "dry hole" and not to be used for water. Dry holes not cased, sealed and completed as an individual well or public water supply well shall be destroyed under permit prior to abandonment of the site or commencement of a new drill hole by the driller. Observation or test wells used in the investigation or management of groundwater basins by governmental agencies or 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, and preferably shall be locked when measurements are not being made. When these wells are no longer used for this purpose or for supplying water, they shall be considered abandoned.

"Active well" shall mean an operating water well.

"Annular space" shall mean the space between two well casings or between the casing and the wall of the drilled hole.

"Aquifer" shall mean a geologic formation, group of formations or part of a formation that is water-bearing and which transmits water in sufficient quantity to supply springs and wells.

"Artesian well" shall mean a well, which obtains its water from a confined aquifer. The water level in an artesian well stands some distance above the top of the aquifer it taps. Where the pressure is sufficient to force the water level above the surface of the ground, the well is termed a flowing artesian well.

"Bailer" shall mean a long narrow bucket with a valve in the bottom used to remove cuttings or fluids from a well.

"Bentonite" shall mean a highly plastic colloidal clay composed largely of montmorillonite used as a drilling fluid additive or as a sealer.

"Casing" shall mean a tubular retaining structure which is installed in the well bore to maintain the well opening.

"Casing vent" shall mean an opening into the top of the well to minimize the possibility of contamination caused by the creation of a partial vacuum during pumping. "Cathodic protection well" shall mean any artificial excavation in excess of fifty feet constructed by any method for the purpose of installing equipment or facilities for the protection electrically of metallic equipment in contact with the ground.

"Clay" shall mean a uniform fine-grained geologic material (grain size less than 0.004 millimeter in diameter) which has a very low permeability.

"Community water supply wells" shall mean a well used for domestic purposes, regardless of type of ownership, if such system has at least five service connections or regularly serves an average of at least twenty-five individuals daily at least sixty days of the year. These systems are also subject to Chapter 7 of Part I of Division 5 of the California Health and Safety Code and are defined completely in California Administrative Code, Title 22, Section 64411(b). The department of environmental health will determine the classification of water systems.

"Conductor casing" shall mean a tubular retaining structure installed in the upper portion of a well between the wall of the drilled hole and the inner well casing.

"Cone of depression" is a depression in the ground-water table or potentiometric surface that has the shape of an inverted cone and develops around a well from which water is being withdrawn. It defines the area of influence of a well.

"Confined groundwater" shall mean groundwater under pressure whose upper surface is the bottom of an impermeable bed or a bed of distinctly lower permeability than the material in which the confined water occurs. Confined groundwater moves under the difference in head between the intake and discharge areas of the water body.

"Connate water" shall mean water entrapped in the interstices of a sedimentary rock at the time it was deposited. These waters may be fresh, brackish, or saline in character. "Connate water" usually applies only to water found in geologically older formations.

"Consolidated material" shall mean a geologic material whose particles are stratified, cemented, or firmly packed together. "Consolidated material" usually occurs at depth, i.e., sandstone.

"Contamination" shall mean an impairment of the quality of waters of the state by waste to a degree which creates a hazard to the public health through poisoning or through the spread of disease. "Contamination" shall include any equivalent effect resulting from the disposal of waste, whether or not waters of the state are affected.

"Destroyed well" shall mean a well that has been properly filled so that it cannot produce water nor act as a vertical conduit for the movement of groundwater or surface water.

"Deterioration" shall mean an impairment of water quality.

"Driller's mud" means a fluid composed of water and clay used in the drilling (primarily rotary) operation. The mud serves to remove cuttings from the hole, to clean and cool the bit, to reduce friction between the drill stem and the sides of the hole, and to plaster the sides of the hole. Such fluids range from relatively clear water to carefully prepared mixtures of special purpose compounds.

"Drive shoe" shall mean a forged steel collar with a cutting edge fastened onto the bottom of the casing to shear off irregularities in the hole as the casing advances and to protect the lower edge of the casing as it is driven.

"Gravel-packed well" shall mean a well in which filter material (sand, gravel, etc.) is placed in the annular space between the casing and the bore-hole to increase the effective diameter of the well and to prevent fine-grained material from entering the well during pumping.

"Groundwater" shall mean that part of the subsurface water which is in the zone of saturation.

"Groundwater basin" is a basin consisting of an area underlain by permeable materials, which are capable of storing or furnishing a significant water supply; the basin includes both the surface area and the permeable materials beneath it.

"Grout" shall mean a fluid mixture of cement and water of a consistency that can be forced through a pipe and placed as required. Various additives, such as sand, bentonite, and hydrated lime, are used to meet certain requirements. For example, sand is added when a considerable volume of grout is needed.

"Horizontal wells" shall mean water wells drilled horizontally or at an angle with the horizon (as contrasted with the common vertical well). This definition does not apply to horizontal drains or "wells" constructed to remove subsurface water from hillsides, cuts, or fills.

"Impairment" shall mean a change in quality of water which makes it less suitable for beneficial use.

"Impermeable" shall mean that property of a geologic material that renders it incapable of allowing water to move through it perceptibly under the pressure differences ordinarily found in subsurface water.

"Impervious strata" shall mean a geologic unit which will not transmit water in sufficient quantity to furnish an appreciable supply to wells or springs.

"Inactive or standby well" shall mean a well not routinely operating but capable of being made operable with a minimum of effort.

"Individual well" shall mean a well used to supply domestic water to an individual residence and all other wells not defined as a community water supply well.

"Monitoring wells" shall mean any artificial excavation by any method for the purpose of monitoring fluctuations in groundwater levels, quality of groundwaters, or the concentration of contaminants in underground water or vadose zones.

"Packer" shall mean of device used to plug or seal a well at a specific depth; frequently used as retainers to keep grout in position until it sets.

"Perforations" shall mean openings in a well casing to allow the entrance of groundwater into the well. Perforations may be made either before or after installation of the casing.

"Permeability" shall mean the capacity of a geologic material for transmitting fluid. The degree of permeability depends upon the size and shape of the openings and extent of the interconnections.

"Pollution" shall mean an alteration of the quality of the waters of the state by waste to a degree which unreasonably affects such waters for beneficial uses, or affects facilities which serve such beneficial uses. "Pollution" may include "contamination."

"Pressure grouting" shall mean a method of forcing grout into specific portions of a well, such as the annular space, for sealing purposes. Pressure is maintained for a length of time sufficient for the cementing mixture to set.

"Quality of water or water quality" shall mean chemical, physical, biological, bacteriological, radiological, and other properties and characteristics of water, which affects is use.

"Recharge and injection wells" shall mean wells constructed to introduce water into the ground as means of replenishing groundwater basins, repelling the intrusion of seawater, or disposing of wastewater.

"Rehabilitation" shall mean 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.

"Sanitary seal" shall mean a grout, mastic, or mechanical device to make a watertight joint between the pump and the casing or the concrete base or around wires extending into the casing.

"Screen or well screen" shall mean a factory-perforated casing used in a well that maximizes the entry of water from the producing zone and minimizes the entrance of sand.

"Surface seal" shall mean a monolithically poured concrete platform constructed around the top of the well casing on thoroughly compacted earth (four feet by four feet by four inches).

"Test wells" shall mean wells constructed for the purpose of obtaining the information needed to design a well prior to its construction. Such wells are not to be confused with "test holes" or "exploration holes" which are temporary in nature (i.e., uncased excavations whose purpose is the immediate determination of existing geologic and hydrologic conditions). Test wells are cased and can be converted to monitoring or production wells.

"Tremie" shall mean a tubular device or pipe used to place grout in the annular space.

"Unconfined (free) groundwater" shall mean groundwater that has a free water table, i.e., water not confined under pressure beneath relatively impermeable rocks.

"Unconsolidated material" shall mean a sediment that is loosely arranged or unstratified or whose particles are not cemented together occurring either at the surface or at depth.

"Waste" shall mean sewage, and/all other waste substances, liquid, solid, gaseous, or radioactive, associated with human habitation, or of human or animal origin, or from any producing, manufacturing, or processing operation of whatever nature, including such waste placed within containers of whatever nature prior to, and for purposes of disposal.

"Water well" shall mean any artificial excavation constructed by any method for the purposes of extracting water from, or injecting water into, the underground. This definition shall not include oil and gas wells, or geothermal wells constructed under the jurisdiction of the department of conservation, except those wells converted to use as water wells; or wells used for the purpose of dewatering excavations during construction or stabilizing hillsides or earth embankments.

"Well pit" shall mean an excavation in which the top of the well casing is below the ground surface.

(Ord. 1707 § 1(part), 1999)