020-12 Wyo. Code R. §§ 12-11 - Source Development

(a) 2018 TSS, parts 2.10, sample taps; 3.1.4.1-3.1.4.1(i), surface water, structures, design of intake structures; 3.1.4.3-3.1.4.3(f) surface water, structures, offstream raw water storage reservoir; 3.1.6-3.1.6.3, surface water, impoundments and reservoirs; 3.2.3.2, groundwater, location, continued sanitary protection; 3.2.4-3.2.4.14(b)(4), groundwater, general well construction; 3.2.5-3.2.5.4, groundwater, testing and records; 3.2.6.1-3.2.6.1(c), groundwater, aquifer types and construction methods--special conditions, sand or gravel wells; 3.2.6.2-3.2.6.2(b)(7), groundwater, aquifer types and construction methods--special conditions, gravel pack material; 3.2.6.4-3.2.6.4(d),groundwater, aquifer types and construction methods--special conditions, infiltration lines; 3.2.6.5-3.2.6.5(b), groundwater, aquifer types and construction methods--special conditions, limestone or sandstone wells; 3.2.7.3-3.2.7.3(c)(3), groundwater, well pumps, discharge piping and appurtenances, discharge piping; 3.2.7.4-3.2.7.4(d), groundwater, well pumps, discharge piping and appurtenances, pitless well units; 3.2.7.6, groundwater, well pumps, discharge piping and appurtenances, casing vent; 3.2.7.7-3.2.7.7(b), groundwater, well pumps, discharge piping and appurtenances, water level measurement; 3.2.7.8-3.2.7.8(b), groundwater, well pumps, discharge piping and appurtenances, observation wells; are herein incorporated by reference.

(b) Surface water intake structures that operate in the winter shall be capable of minimizing the formation of ice on the intake.

(c) Transmission lines and interconnecting process piping shall be capable of withstanding the forces and conditions they will be subject to and comply with the following specifications for water service, as applicable:

(i) AWWA C200;

(ii) AWWA C207;

(iii) AWWA C208;

(iv) AWWA C220;

(v) AWWA C228;

(vi) AWWA C300;

(vii) AWWA C301;

(viii) AWWA C302;

(ix) AWWA C303;

(x) AWWA C304;

(xi) AWWA C900;

(xii) AWWA C901;

(xiii) AWWA C903;

(xiv) AWWA C904;

(xv) AWWA C906;

(xvi) AWWA C907;

(xvii) AWWA C909;

(xviii) AWWA C950;

(xix) ASTM A53;

(xx) ASTM A134;

(xxi) ASTM A135;

(xxii) ASTM A139;

(xxiii) ASTM D2846;

(xxiv) ASTM F480;

(xxv) ASTM F645;

(xxvi) ASTM F877;

(xxvii) ASTM F23891;

(xxviii) ASTM F2806;

(xxix) ASTM F2855;

(xxx) ASTM F2969;

(xxxi) API 5L:

(A) Grade B;

(B) Grade X42;

(C) Grade X46;

(D) Grade X52;

(E) Grade X56;

(F) Grade X60;

(G) Grade X65;

(H) Grade X70; or

(I) Grade X80.

(d) Designs shall not include any customer service connection from the raw water transmission line to the treatment plant unless there are provisions to treat the water to meet the requirements of this Chapter, or the sole purpose of the service is for irrigation or agricultural water use. For irrigation agricultural services, applicants shall conduct a hazard classification and implement appropriate backflow prevention.

(e) Designs that include groundwater source development shall comply with the following requirements:

(i) Proposed designs shall have a water sample tap installed on groundwater sources prior to treatment or water storage and shall include:

(A) Two wells that are each capable of supplying the average daily demand with the largest producing well out of service; or

(B) One well and finished water storage that together equal twice the maximum daily demand; or

(C) For public water supplies that, as determined by the Administrator, are neither community water systems nor nontransient noncommunity water systems, one well that is capable of supplying the maximum daily demand.

(ii) Wells shall maintain the following minimum isolation distances:

(A) If domestic wastewater is the only wastewater present and the design domestic sewage flow is less than 2,000 gpd, the following minimum isolation distance shall be maintained:

Table 1. Isolation Distances for Domestic Sewage Flows Less than 2,000 gpd

Source of Domestic Wastewater	Minimum Distance to Well
Storm and Sanitary Sewer Collection Systems	50 feet
Septic tank	100 feet
Absorption system	200 feet

(B) If domestic wastewater is the only wastewater present and the design domestic sewage flow is greater than 2,000 gpd but less than 10,000 gpd, the following minimum isolation distances shall be maintained:

Table 2. Isolation Distances for Domestic Sewage Flows Greater than 2,000 gpd

Source of Domestic Wastewater	Minimum Distance to Well
Storm and Sanitary Sewer Collection Systems	0 feet
Septic tank	100 feet
Absorption system	500 feet

(C) If domestic wastewater is the only wastewater present and the design domestic sewage flow is greater than 10,000 gallons per day or non-domestic wastewater is present the required isolation distance shall be determined by a subsurface study, in accordance with the requirements of Water Quality Rules Chapter 3, Section 4, but shall not be less than those required in Tables 1 and 2 of this Section.

(iii) Wells shall maintain the following minimum isolation distances from buildings and property lines:

(A) When a well is outside of a building, the well shall be located so that the surface casing has a clearance radius of a minimum of 10 feet horizontally and will clear any projection from the building;

(B) When a well is located inside a building:

(I) The top of the casing and any other well opening shall not terminate in the basement of the building, or in any pit or space that is below natural ground surface unless the well is completed with a properly protected submersible pump or provided with provisions for drainage to the ground surface that is not subject to flooding by surface water;

(II) Wells located in a structure shall be accessible to pull the casing, pipe, or pump; and

(III) The structure shall have overhead access.

(C) Wells shall be located at least 50 feet from any property line.

(iv) Applicants for wells shall complete testing and maintain records as follows:

(A) Yield and drawdown tests shall be performed on every production well after construction or subsequent treatment and prior to placement of the permanent pump. The test methods shall be clearly indicated in the specifications. The test pump capacity, at maximum anticipated drawdown, shall be at least 1.5 times the design rate anticipated. The well shall be test pumped at the desired yield (design capacity) of the well for at least 24 consecutive hours after stabilized drawdown. Alternatively, the well may be pumped at a rate of 150 percent of the desired yield for at least six continuous hours after stabilized drawdown.

(B) Every well shall be tested for plumbness and alignment in accordance with AWWA A100.

(v) In addition to meeting the requirements of Section 8 of this Chapter, plans for wells developed through acidizing activities shall also include the following elements:

(A) Information on the geology of the area that contains descriptions of:

(I) Known or potential faults, fractures, springs, karst features (such as sinkholes and other similar features) within a one-mile radius of the proposed well; and

(II) Faults and fractures that may extend from the acidized zone into overlying and underlying geologic formations and a description of any measures that will be taken to ensure that the acidized solution does not migrate into any of those geologic formations.

(B) For wells developed within a radius of one mile of existing wells, applicants shall submit plans that analyze the risk and mitigation measures to be taken to prevent impacts to those wells and the risk and mitigation measures for any potential effects to each existing well;

(C) Existing information on the location of other wells (such as water supply, oil and gas, mineral development wells) within a one-mile radius of the proposed well, including any wells that intercept the acidized zone, and for wells that intercept the acidized zone:

(I) An analysis of whether or not those wells that intercept the acidized zone have been properly plugged and abandoned;

(II) An analysis of whether or not those wells have been properly cased and cemented; and

(III) A description of what measures will be or have been taken to prevent the acidized solution from migrating vertically in the annular space or casing of the existing wells into overlying or underlying geologic formations.

(D) A description of the borehole drilling phase and what measures will be taken to minimize the introduction of lost circulation materials into aquifers when encountering under-pressured geologic formations or other factors that may lead to a loss of circulation;

(E) A description of the acid injection process and the measures that will be taken to ensure that injection pressures do not create fractures in the overlying and underlying geologic formations and through which the acidized solution may migrate;

(F) A description of the volume and content of the acid and any other chemical compounds to be used during acidizing activities, including the management of the acid and chemical compounds prior to acidizing and final disposition of any acid, water, or chemical mixtures recovered from the well after acidizing activities are completed;

(G) A description of the measures that will be or have been taken to ensure that the recovery of the acidized solution is of sufficient duration and volume to eliminate the potential for acidic impacts to other wells completed within the injection zone; and

(H) A description of the methods to be performed to establish the placement and integrity of the annular seal and casing prior to acidization of the well.

(vi) During any well construction or modification, the well and surrounding area shall be adequately protected to prevent any groundwater contamination. Surface water shall be diverted away from the construction area.

(vii) All wells shall comply with the following construction standards:

(A) Dug wells shall be constructed according to the State Engineer's standards;

(B) Drilled, driven, jetted, or bored wells shall have an unperforated casing that extends from a minimum of 12 inches above the concrete surface and 18 inches above natural ground surface and the design shall demonstrate compliance with Water Quality Rules, Chapter 26, Section 8;

(C) In gravel-packed wells or artificial filter-packed wells, aquifers containing inferior quality water shall be sealed by pressure grouting, or with special packers or seals, to prevent such water from moving vertically in gravel-packed portions of the well. Gravel-packed wells shall meet the following sealing requirements:

(I) If a permanent surface casing is not installed, the annular opening between the casing and the drill hole shall be sealed in the top 10 feet with concrete or cement grout; or

(II) If a permanent surface casing is installed, it shall extend to a depth of at least 10 feet. The annular opening between this outer casing and the inner casing shall be covered with a metal or cement seal.

(D) When naturally flowing water is encountered in a well, unperforated casing shall extend into the confining layer overlying the water-bearing zone. This casing shall be adequately sealed with cement grout into the confining zone and shall extend at least 10 feet into the target aquifer to prevent both surface and subsurface leakage from the water-bearing zone. The method of construction shall be such that during the placing of the grout and the time required for it to set, no water shall flow through or around the annular space outside the casing, and no water pressure sufficient to disturb the grout prior to final set shall occur. Drilling operations shall not be continued into the water-bearing zone until the grout has set completely. If leakage occurs around the well casing or adjacent to the well, the well shall be recompleted with any seals, packers, or casing necessary to eliminate the leakage completely.

(I) Flowing wells shall be constructed to control the flow of water from the well. The well grouting shall be engineered to prevent the movement of water along the well casing and to prevent the migration of pressurized water into upper aquifers. A flow control device shall be installed into the wellhead to control the flow of water from the well. The well discharge or overflow line installations must connect to the well casing at least 12 inches above ground and be valved. The size of the air gap between the overflow line from the well to drainage structure shall be twice the diameter of the well overflow pipe. Overflow water must be drained and diverted to prevent ponding around the well casing.

(II) There shall be no direct connection between any discharge pipe and a sewer or other source of pollution and all terminations shall provide for an air gap of 3 pipe diameters for drain or overflow above an opening to a sanitary or storm sewer.

(E) If mineralized water or water known to be polluted is encountered during the construction of a well, the aquifer or aquifers containing such inferior quality of water shall be adequately cased or sealed off to prevent water from entering the well and to prevent water from moving up or down the annular space.

(I) For wells that penetrate multiple aquifers, mineralized water shall be excluded from the well if water is taken from other, non-mineralized aquifers.

(II) Applicants that propose to use mineralized water as a public water supply shall demonstrate that any necessary treatment will comply with the drinking water quality standards required by 40 CFR Part 141.

(F) Existing oil or gas wells, private water wells, or exploration test holes that can be completed to conform to all minimum construction standards required by this Chapter may be converted for use as a public water supply well. The permit application shall identify all actions to be completed to achieve compliance with this Chapter.

(viii) The minimum grout thickness for public water supply wells shall be determined in accordance with AWWA Standard A100, part 4.7.8.3.

(ix) Well seals shall meet the following requirements:

(A) The annular space shall be sealed to protect against contamination or pollution by the entrance of surface or shallow subsurface waters; and

(B) Annular seals shall be installed to provide protection for the casing against corrosion, to ensure the structural integrity of the casing, and to stabilize the upper formation.

(x) Upper terminal well designs that include a concrete floor shall demonstrate a slope of one inch per foot away from the casing.

(xi) Well pumps shall be located at a point above the top of the well screen.

(xii) An accessible check valve that is not located in the pump column shall be installed in the discharge line of each well between the pump and the shut-off valve. Additional check valves shall be located in the pump column as necessary to prevent negative pressures on the discharge piping.

(xiii) A pitless adaptor or well house shall be used where needed to protect the water system from freezing.

(xiv) A frost pit may be used only in conjunction with a properly protected pitless adaptor.

(xv) Wells with diameters that are greater than four inches shall be equipped with an air line for water level measurements or, in the case of a flowing artesian well, with a pressure gauge that will indicate pressure.

(xvi) An instantaneous and totalizing flow meter equipped with nonvolatile memory shall be installed on the discharge line of each well in accordance with the manufacturer's specifications. Meters installed on systems with variable frequency drives shall be capable of accurately reading the full range of flow rates.

(xvii) Test wells and groundwater sources that are sealed for plugging and abandonment in accordance with requirements of Water Quality Rules Chapter 26, Section 11 shall be sealed by filling with neat cement grout. The filling materials shall be applied to the well hole through a pipe, or tremie.

(xviii) Designs for groundwater sources that are subject to 40 CFR 141.402(a)(1)(i) and either 40 CFR 141.402(a)(1)(ii) or 40 CFR 141.402(a)(1)(iii) shall demonstrate compliance with 40 CFR 141.402(e).

(f) Facilities that include spring development shall meet the following requirements:

(i) Spring collection systems shall be constructed to collect spring water while preventing contamination of the source from the ground surface or other contaminant sources.

(ii) Seepage springs shall have a trench for the collection site that extends at least six inches into the impervious layer, but not entirely through the impervious layer. Concentrated springs shall be developed down to bedrock.

(iii) A bed of clean and disinfected rock that extends the width of the spring from which water is being collected shall be installed at the collection site.

(iv) The collection site shall:

(A) Be covered with 60 mil plastic sheeting or an equivalent puncture-proof and water-proof barrier; and

(B) Be protected from damage during back-fill and re-grading of the site to the original surface elevation with protective fabric or sand.

(v) Collecting walls shall be:

(A) Constructed immediately downstream of the collection site; and

(B) Made of concrete, or other material that meets the requirements of Section 15(b)(ii) of this Chapter;

(vi) The spring water collection pipe shall be installed in accordance with the USDA NRCS Part 631 National Engineering Handbook, Chapter 32, part 631.3201(b)(iii) for delivery pipes and shall meet the following requirements:

(A) The size of the collection pipe shall be sufficient to convey the flow of the spring; and

(B) Pipe material and appurtenances shall comply with allowable well construction material for water distribution in accordance with the standards listed in paragraph (c) of this Section.

(vii) Appropriate bedding and cover material shall protect the spring collection system from damage and freezing.

(viii) The Administrator shall determine the spring protection area, based on the information submitted in the engineering design report required by Section 8 of this Chapter, which shall be no less than the isolation distances in (e)(ii) of this Section. The Administrator may require additional setback distances if the engineering design report demonstrates the additional distance is required to prevent contamination of the source from the ground surface or other contaminant sources.

(ix) All potential sources of contamination shall be removed from the spring protection area.

(x) The spring collection site shall include fencing or other protective features that are constructed and secured to exclude large animals and unauthorized persons from entering the protection area.

(A) Fencing shall be designed to withstand animals and snow loading. Other protective systems may be proposed.

(B) Fencing shall include an entry point to allow access by authorized persons for inspection and maintenance activities.

(xi) The spring collection site shall include a diversion ditch that is constructed on the upstream side of the spring collection site to route surface water flows away from the collection area. The diversion ditch shall be located a minimum of 10 feet away from the collection wall.

(xii) The spring collection site shall be equipped to disinfect water prior to distribution and shall include sampling ports before and after the disinfection application point. The equipment shall be maintained and available to operate for its intended use.

(xiii) Spring box designs shall comply Section 15(a), (b), (f-j), and (l) of this Chapter. Combined spring box and finished water storage designs shall comply with Section 15 of this Chapter.

(xiv) All designs for the spring collector box and collecting walls shall be performed by a Wyoming registered professional engineer. The plans or contractor furnished information shall be signed and sealed by a Wyoming registered professional engineer.

Notes

020-12 Wyo. Code R. §§ 12-11

Amended, Eff. 7/26/2023.