Wyoming Administrative Code, Chapter 12, Section 12-16 - Distribution Systems | Wyoming Administrative Code

(a) 2018 TSS, parts 8.2-8.2.4(b), system design; 8.3, valves; 8.4-8.4.4(d), hydrants; 8.5-8.5.2(c), air relief valves; 8.6, valve, meter, and blow-off chambers; 8.7.3, installation of water mains, cover; 8.7.4, installation of water mains, blocking; 8.7.6, installation of water mains, pressure and leakage testing; 8.7.7, installation of water mains, disinfection; 8.7.8, installation of water mains, external corrosion; 8.7.9, installation of water mains, separation from other utilities; 8.8.2-8.8.2(b), separation distances from contamination sources, parallel installation; 8.8.3-8.8.3(b), separation distances from contamination sources, crossings; 8.8.6, separation distances from contamination sources, sewer manholes, inlets, and structures; 8.9-8.9.1, surface water crossings, above-water crossings; 8.9.2-8.9.2(c); surface water crossings, under water crossings; 8.11.1, water services and plumbing, plumbing; 8.12, service meters; are herein incorporated by reference.

(b) Distribution systems shall be constructed of commercial pipe that conforms to the following standards:

(i) PVC pipe:

(A) Less than four inches diameter, ASTM D 2241; or

(B) Four inches and larger diameter, AWWA C900.

(ii) Ductile iron, AWWA C151;

(iii) Fiberglass pressure pipe, AWWA C950;

(iv) Polyethylene pipe:

(A) 3/4 inch through three inches diameter, AWWA C901;

(B) Four inches through 65 inches diameter, AWWA C906; or

(v) Other material submitted with the permit application and approved by the Administrator.

(c) Flanged piping shall not be allowed for buried pipe except for connection to valves.

(d) New water mains shall be sized after the hydraulic analysis required by Section 9(l)(i) of this Chapter and the design shall demonstrate that:

(i) At maximum day demand plus current State of Wyoming-required fire flow, or the fire flow of an authority having jurisdiction, the pressure in the municipal distribution system will not fall below 20 pounds per square inch (psi); and

(ii) The normal system working pressure shall be greater than 35 psi.

(e) When fire protection is provided, the water main system shall be designed to also serve fire flows.

(f) Hydrants shall:

(i) Have hydrant leads that are a minimum of six inches in diameter;

(ii) Have valves installed;

(iii) Be protected from freezing at hydrant leads and barrels;

(iv) Where groundwater levels are above the gravel drain area, hydrants shall be pumped dry or otherwise dewatered and hydrant weep holes shall not be used; and

(v) Have drains that are not connected to or located within 10 feet of a sanitary sewer or storm drain.

(g) Fire hydrants or active service taps may be substituted for air relief in 6- and 8-inch lines.

(h) Where excavation is performed for distribution systems:

(i) The trench bottom shall be excavated for the bell of the pipe;

(ii) All rock shall be removed within six inches of the pipe; and

(iii) The trench shall be dewatered for all work.

(i) Distribution system bedding for rigid pipe shall be designed in accordance with ASTM C12 Classes A, B, or C. Flexible pipe bedding shall be designed in accordance with ASTM D2321 Class I, II, or III.

(j) Distribution system pipe shall be joined to ensure a watertight fitting and installed in accordance with the following standards, as applicable:

(i) For ductile iron pipe, AWWA C600;

(ii) For PVC pipe, AWWA M23; and

(iii) For HDPE pipe, AWWA M55.

(k) Backfill for distribution systems shall:

(i) Be performed without disturbing pipe alignment;

(ii) Not contain debris, frozen material, unstable material, or large clods;

(iii) Not contain rocks or stones that are greater than three inches in diameter within two feet of pipe; and

(iv) Be compacted to a density equal to or greater than the surrounding soil.

(l) Distribution systems shall meet the following requirements for separation of water mains from sanitary and storm sewers:

(i) Where the minimum vertical or horizontal separation distances required by incorporation by reference of 2018 TSS parts 8.8.2 and 8.8.3 of paragraph (a) of this Section cannot be met, the sewer or water line shall be placed in a separate conduit pipe or meet the flow-fill requirements of paragraphs (ii) and (iii) of this Paragraph (l);

(ii) Flow-fill for pipelines shall comply with the following:

(A) Cement-treated fill, non-shrink backfill, low-density concrete backfill, or structural backfill may be used as flow-fill when the material has a 28-day compressive strength of 30-60 psi;

(B) The pipe to be encased shall be laid on a four to six-inch bed of washed gravel that has been widened, with the walls of the trench benched away from the center-line of the trench, so the pipe is uniformly supported over the length or supported on blocks no further than 10 feet apart;

(C) The flow-fill and washed gravel or blocks shall rest on an undisturbed trench bottom;

(D) The pipe shall not move laterally or float during placement of the flow-fill and the line and grade of the pipe shall be maintained; and

(E) The flow-fill shall extend from trench sidewall to trench sidewall and extend at least two inches above the top of the pipe.

(iii) Flow-fill for pipe crossings shall comply with the following:

(A) To the extent possible, there shall be no joints or taps within nine feet of the crossing;

(B) The flow-fill shall extend from undisturbed earth at the bottom of the lower pipe to at least two inches above the top of the upper pipe;

(C) The block of flow-fill shall be wide enough to ensure the structural integrity of the installation; and

(D) Pipes that cross one another shall be separated by a minimum of two inches when encased in flow-fill.

(m) Cross-connections shall comply with the following requirements:

(i) There shall be no water service connection installed or maintained between a public water supply and any water user whereby unsafe water or contamination may backflow into the public water supply.

(A) To protect all public water supplies from the possibility of the introduction of contamination due to cross-connections, the water supplier shall:

(I) Require backflow prevention devices for each water service connection in accordance with Table 4 of this Section, with the exception of (B)(I) residential water service connections and (B)(II) domestic non-residential water service connections;

(II) Take appropriate actions that may include:

1. Immediate disconnection for any water user that fails to maintain a properly installed backflow prevention device; or

2. Compliance with other measures as identified in this Section.

(III) Any high hazard non-residential connection to any public water supply shall be protected by the backflow prevention device required by Table 4.

(IV) Water suppliers shall establish record keeping and management procedures to ensure that requirements of this regulation for installation and maintenance of backflow prevention devices are being met.

(B) The method of backflow control, selected from Table 4, shall be determined based upon the degree of hazard of the cross-connection and the cause of the potential backflow. Hazards shall be classified as high hazard or low hazard. The potential cause of the backflow shall be identified as being back-siphonage or back-pressure.

(I) Residential water service connections shall be considered to be low hazard back-siphonage connections unless determined otherwise by a Hazard Classification.

(II) Domestic non-residential water service connections (such as schools without laboratories, churches, office buildings, warehouses, and motels) shall be considered to be low hazard back-pressure connections unless determined otherwise by a Hazard Classification conducted by the water supplier.

(III) Any water user's system with an auxiliary source of supply shall be considered to be a high hazard, back-pressure cross-connection. A reduced pressure principle backflow device shall be installed at the water service connection to any water user's system with an auxiliary source of supply.

(IV) All water loading stations shall be considered high hazard connections. A device, assembly, or method consistent with Table 4 shall be provided.

(V) Non-domestic commercial or industrial water service connections (such as restaurants, refineries, chemical mixing facilities, sewage treatment plants, mortuaries, laboratories, laundries, dry cleaners, irrigation systems, and facilities producing or using hazardous substances) shall be considered to be high hazard back-pressure connections unless determined otherwise by a Hazard Classification. For some of these service connections, a Hazard Classification may result in a determination of a back-siphonage or low hazard classification. The backflow prevention device required shall be appropriate to the degree of hazard established by the Hazard Classification. Where potential high hazards exist within the non-residential water user's system, even though such high hazards may be isolated at the point of use, an approved backflow prevention device shall be installed and maintained at the water service connection.

(C) Determination of the hazard classification of a water service connection is the responsibility of the water supplier. The water supplier may require the water user to furnish a Hazard Classification Survey to be used to determine the Hazard Classification.

(D) Hazard Classification Surveys that have been conducted by Hazard Classification Surveyors that have been certified by another state certification program shall include the following information for Administrator approval:

(I) Documentation that indicates the Hazard Classification Surveyor has received certification from the regulatory agency that issued the current certification that states the name of the Hazard Classification Surveyor, the status of their certification, the date originally issued, the expiration date, and the classification for which the Hazard Classification Surveyor is certified; and

(II) Any disciplinary action imposed against the applicant; if any.

(E) All backflow prevention devices shall be in-line serviceable (repairable), in-line testable except for devices meeting ASSE 1024, and installed in accordance with manufacturer instructions and applicable plumbing codes.

(F) All backflow prevention devices must have a certification by an approved third-party certification agency. Approved certification agencies are:

(I) American Society of Sanitary Engineers (ASSE);

(II) International Association of Plumbing/Mechanical officials (IAPMO); and

(III) Foundation for Cross-Connection Control and Hydraulic Research, University Of Southern California (USC-FCCCHR).

(G) Backflow prevention devices at water service connections shall be inspected and certified by a certified backflow assembly tester at the time of installation. Certification of the assembly tester shall be by one of the following:

(I) The American Society of Sanitary Engineers (ASSE); or

(II) American Backflow Prevention Association (ABPA).

(H) Backflow prevention devices installed at high hazard non-residential cross-connections shall be inspected and tested on an annual basis by a certified backflow assembly tester.

(I) If any device is found to be defective or functioning improperly, it shall be immediately repaired or replaced. Failure to make necessary repairs to a backflow prevention device will be cause for the water service connection to be terminated.

(J) All public water suppliers shall report any high hazard backflow incident within seven days to the Division. The backflow incident shall be reported on a form provided by the Administrator.

(ii) Neither steam condensate nor cooling water from engine jackets or other heat exchange devices shall be returned to the public water supply after it has passed through the water service connection.

Table 4. Backflow Prevention Devices, Assemblies and Methods

	Degree of Hazard
Device, Assembly, or Method	Low Hazard		High Hazard		Notes
Device, Assembly, or Method	Back-Siphonage	Back-Pressure	Back-Siphonage	Back-Pressure	Notes
Airgap	X	X	X	X	See Note 1 and Note 2
Atmospheric Vacuum Breaker	X		X		Not allowed under continuous pressure
Spill-proof Pressure-type Vacuum	X		X
Double Check Valve Backflow Preventer	X	X
Pressure Vacuum Breaker	X		X
Reduced Pressure Principal Backflow	X	X	X	X	See Note 2,
Dual Check	X				Restricted to residential services

Note 1: Minimum Airgap for Water Distribution. For spouts with an effective opening diameter of 1/2 inch or less, the minimum airgap when the discharge is not affected by side walls shall be one inch. The minimum airgap when the discharge is affected by sidewalls shall be 1 1/2 inches. For effective openings greater than 1/2 inch, the minimum airgap shall be two times the effective opening diameter when the discharge is not affected by sidewalls. The minimum airgap when the discharge is affected by sidewalls shall be three times the effective opening diameter.

Note 2: Extreme Hazards. In the case of any water user's system where, in the opinion of the water supplier or the Administrator, an undue health threat is posed because of the presence of extremely toxic substances or potential back pressures in excess of the design working pressure of the device, the water supplier may require an airgap at the water service connection to protect the public water system.

Wyoming Administrative CodeAgency 020 - Environmental Quality, Dept. ofSub-Agency 0011 - Water QualityChapter 12 - DESIGN AND CONSTRUCTION STANDARDS FOR PUBLIC WATER SUPPLIESSection 12-16 - Distribution Systems

Wyoming Administrative Code
Agency 020 - Environmental Quality, Dept. of
Sub-Agency 0011 - Water Quality
Chapter 12 - DESIGN AND CONSTRUCTION STANDARDS FOR PUBLIC WATER SUPPLIES
Section 12-16 - Distribution Systems