§ 34-116. Construction criteria.

(a)

Location. Water supplies shall be protected from surface contamination through complying construction and adequate grading of the adjacent area. No surface runoff shall be allowed to cover, accumulate over, or pass within ten feet of the wellhead. Wells shall be located at the maximum distance from potential sources of contamination, and in compliance as set forth in [section 34-120] Table C, "Well Separation Distance Requirements". No water supply shall be located in a floodplain unless adequate provisions are made to prevent submergence of well casing, pumps, appurtenances, etc., as approved by the department. The top of the well casing shall be a minimum of two feet above the highest flood level of record. Water supplies shall be located to be accessible for cleaning, testing, inspection, and maintenance.

(b)

Materials. All materials used in the construction (refer to diagrams of a bored and/or drilled well) of a water supply shall be capable of excluding groundwater, as applicable, for the expected life of the well. No materials shall be used which may be toxic or have an objectionable odor or taste. All materials, equipment, and appurtenances shall be required and installed in accordance with this article, applicable building and plumbing codes, the Georgia Safe Drinking Water Act of 1977 (O.C.G.A. § 12-5-170 et seq.) and other standards as determined by the board of health. The following requirements apply to construction of a new well:

(1)

Casing. All permanent casing, liners, and other material must be new and adequate to protect the well against entrance of pollutants or contaminants during the expected life of the well. The casing material shall be of steel, plastic, or concrete and must meet nationally accepted standards and specifications for well casing. Authorities include, but are not limited to, American Society for Testing and Materials (ASTM); American Water Works Association, (AWWA); and National Sanitation Foundation, (NSF). No sewer pipe shall be used for private or semi-public water supply systems.

(2)

Sealants. Grout, when used as a sealant, shall consist of neat cement grout, bentonite clay, or concrete. Cement used in grout shall meet the requirements of the current "Standard Specification for Portland Cement" (ASTM) C150, types I (common construction cement), III (high early strength) and V (for high sulfate resistance, i.e., corrosive waters). Water used in sealant mixtures shall be potable. Materials used as additives in Portland cement mixtures shall meet the requirements of the current "Standard Specification for Chemical Admixtures for Concrete."

a.

Neat cement grout shall be composed of one sack of Portland cement (94 pounds) to six to seven gallons of water, depending on the cement type and additives used.

b.

Concrete shall be class A, (six sacks of Portland cement per cubic yard) or class B (five sacks per cubic yard). Aggregates shall meet the requirements of the current (ASTM) C33 "Standard Specification for Concrete Aggregates."

c.

Special quick-setting cement, retardants to setting, and other additives may be used. Hydrated lime (maximum ten percent of the volume of cement) may be added to make the mix more fluid. Bentonite (maximum five percent of the volume of cement) may be added to make the mix more fluid and to reduce shrinkage.

(3)

Well screen. Multi-screened wells shall not connect aquifers, which have differences in water quality that would result in deterioration of the water quality in any aquifer or zone. The well screen, when used, shall:

a.

Be of a standard design and manufactured specifically for the purpose of the well construction;

b.

Be of a strength to satisfactorily withstand chemical and physical forces applied to it during and after installation;

c.

Be designed to permit optimum development of the aquifer with minimum head loss consistent with the intended use of the well; and

d.

Have openings designed to prevent clogging or jamming.

(4)

Gravel. Gravel shall consist of properly sized siliceous, well-rounded, smooth, uniform grain particles to prevent the formation material from entering the well.

(c)

Construction. Criteria for construction of new water supplies shall be in accordance with applicable building and plumbing codes, DNR regulations and other standards as determined by the department.

(1)

Casing. The casing shall meet the following criteria:

a.

Watertight. In bored or driven wells and for the entire length of casing in drilled wells, the casing (and liner) pipe joints shall be watertight to the point of maximum drawdown.

b.

Alignment. The alignment shall be such that the installation and operation of the pump will not be impaired.

c.

Material removal. All drill cuttings and other materials, including drilling fluids and additives, shall be removed from the entire depth of the well, and the well shall be disinfected in accordance with this article.

d.

Sanitary seal. The top of the well casing shall be protected by a sanitary seal or cover to exclude pollutants to the well.

e.

Minimum depth. The well casing shall extend at least 12 inches above the ground surface and to a minimum depth of 20 feet below the ground surface unless bedrock is encountered at a lesser depth.

f.

Contamination. During excavation or drilling, provisions shall be taken to prevent contamination to any aquifer.

g.

Drilling process water. Water for drilling purposes shall be obtained from a source and in a manner, which will not result in contamination of any aquifer.

(2)

Grout. The grout shall meet the following criteria:

a.

Thickness of the grout seal. The thickness of the grout seal shall be at least two inches, and not less than three times the size of the largest coarse aggregate used in the sealing material.

b.

Cleaning annular space. All loose cuttings, drilling mud, or other obstructions shall be flushed from the annular space before placing the seal.

c.

Optional packer. A packer, or similar retaining device, or a small quantity of sealant may be placed and permitted to set at the bottom of the portion before grouting begins, to form a foundation for the seal.

d.

Minimum grout depth. Unless otherwise approved by the department, grouting must be placed in a continuous fashion to a minimum depth of 20 feet or to the bedrock seal.

e.

Grout placement. When emplacing the grouting material, the tremie pipe shall be lowered to the bottom of the zone to be sealed and raised slowly as the grout is introduced.

f.

Gravity installation. Gravity installation of grout (i.e., without the aid of a tremie or grout pipe) will not be allowed unless the portion to be sealed is dry. In no case will it be allowed for a depth of more than 30 feet.

g.

Time frame. Grouting must take place within the five days following completion of a well, except that for a bored well, it shall take place within 24 hours of completion of a well.

(3)

Gravel. All gravel placed in a well shall be clean, washed, free of organic matter disinfected prior to emplacement, or provisions must be made for disinfection in place.

(4)

Vent. Well vents shall be protected with a screen and terminate downward at least 12 inches above the slab or adjacent ground surface.

(5)

Pumps and pumping equipment. Pumps and pumping equipment must include the following criteria:

a.

Pump capacity. Pump capacity shall be consistent with the intended use and yield characteristics of the well.

b.

Easy access. The well pump and related equipment shall be conveniently located to permit easy access and removal for repair and maintenance.

c.

Watertight seal. The base plate of any pump placed directly over a well shall form a watertight seal with the well casing or pump foundation.

d.

Annular space. When the pump is not located directly over the well, the annular space between the casing and pump intake or discharge piping shall be closed with a watertight seal designed specifically for this purpose.

e.

Vent. Proper venting must be provided at the wellhead to allow for pressure changes within the well, except when a suction lift type pump is used.

f.

Hose bibb for sampling. A hose bibb shall be installed at the pressure tank by the pump installer for obtaining water samples.

g.

Priming tee. For an offset-jet pump installations, a priming tee must be installed at the wellhead.

h.

Drop piping/electrical wiring. The drop piping and electrical wiring used in connection with the pump shall meet Underwriters Laboratories (UL) specifications acceptable to the department and current applicable local codes.

i.

Pump priming/potable water. Only potable water shall be used for priming pumps.

(6)

Disinfection. Wells must be disinfected after construction and repair as follows:

a.

Initial disinfection. A well contractor constructing or repairing a well is responsible to ensure that the well is disinfected by properly chlorinating the water supply at the time construction is completed. Subsequent disinfection of any system shall be the owner's responsibility.

b.

Procedure. During an initial or subsequent disinfection of a water supply, the following criteria shall be adhered to:

1.

Chlorine quantity. Chlorine shall be placed in the well in sufficient quantities to produce a chlorine residual of at least 100 parts per million (ppm). A chlorine disinfecting solution may be prepared by adding a stock solution or compound containing chlorine in the proportion shown in Table E, "Chlorination".

2.

Chlorine addition. Chlorine solutions shall be placed in the well only after the pump is installed. The well casing and drop pipe shall be flushed with the well water and the chlorine solution. The pump shall be operated until the solution is detected at the sampling point (hose bibb) to ensure that all parts of the system are exposed to the disinfecting process.

3.

Disinfecting system. The well casing, pump column, and any other equipment above the water level in the well shall be thoroughly rinsed with the chlorine solution as a part of the disinfecting process.

4.

Disinfecting time. The chlorine solution shall remain undisturbed in the well for a period of at least 24 hours.

5.

Chlorine removal. The well shall be operated until the discharge of water is free of the chlorine odor before the system is tested.

6.

Test sample/approval. A bacteriological sample of the water shall be taken by the department. The sample shall be analyzed and determined to be free of E. coli bacteria and otherwise satisfactory for human consumption before final approval is granted.

(Res. No. 05-0616, 5-18-05; Ord. No. 18-0340, Att. A, 5-16-18)