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 12-10 - Design Requirements for Preliminary Treatment and Redundancy

Universal Citation: WY Code of Rules 12-10

Current through September 21, 2024

(a) 2018 TSS, parts 2.9-2.9(c), monitoring equipment; 2.10, sample taps; 2.11, facility water supply; and 2.14, piping color code are herein incorporated by reference.

(b) The proposed design shall demonstrate that the capacity of the water treatment or water production system is designed for the maximum daily demand at the design year based on historical usage records.

(i) Where water use records are not available to establish water use, the design shall include an equivalent per capita water use of at least 125 gallons per day (gpd) for average daily water demand and 340 gpd for maximum daily water demand.

(ii) The plant capacity design shall demonstrate consideration of:
(A) Maximum daily water demand;

(B) Agricultural water use;

(C) Industrial water use; and

(D) Filter backwash quantities. In the absence of data, filter backwash quantity shall be five percent of the maximum daily demand.

(c) The structural design shall demonstrate consideration of:

(i) The seismic zone;

(ii) Groundwater; and

(iii) Soil support that demonstrates:
(A) The applicant has conducted soils investigations or has included documentation of adequate previous soils investigations used to develop the structural design;

(B) Basin slabs have been designed to successfully resist the hydrostatic uplift pressure or include an area dewatering system; and

(C) Consideration of long-span breakage in basins designed to resist uplift.

(d) Proposed treatment facilities locations shall demonstrate that:

(i) No sources of pollution will affect the quality of the water supply or treatment system;

(ii) The facility location is not within 500 feet of landfills, garbage dumps, or wastewater treatment systems; and

(iii) All treatment process structures, mechanical equipment, and electrical equipment will be protected, accessible, and remain fully operational during the maximum flood of record or the 100-year flood, whichever is greater.

(e) Proposed treatment shall demonstrate that the facility will produce potable water that is bacteriologically, chemically, radiologically, and physically safe, as required by 40 CFR Part 141.

(f) Designs for proposed treatment facilities with 100,000 gpd capacity and over shall include duplicate units, as a minimum, for chemical feed, flocculation, clarification, sedimentation, filtration, and disinfection.

(g) Designs for proposed treatment facilities under 100,000 gpd capacity shall include:

(i) Duplicate units as described in paragraph (f) of this Section; or

(ii) Finished water system storage equal to twice the maximum daily demand; and

(iii) Demonstration of consideration of plant design flexibility to account for future changes in source water quality, unexpected need to modify process piping, service area expansion, changing treatment technologies, and equipment life cycles and upgrades.

(h) All treatment facility pumping shall provide the maximum daily demand flow with the largest single-unit not in service. Finished water pumping in combination with finished water storage that floats on the distribution systems shall provide the maximum hourly demand with the largest single-unit not in service. For designs that include fire protection, pumping, and finished water storage that floats on the system shall provide the fire demand plus the maximum daily demand, or the maximum hourly demand, whichever is greater.

(i) Where the finished water storage volume that floats on the distribution system is not capable of supplying the maximum daily demand, the proposed design shall include alternative power for the finished water pumps that demonstrates:

(i) The combined finished water storage volume and pumping capacity supplied by alternative power will be at least adequate to provide the maximum daily demand; and

(ii) The alternative power source will include engine generators, engine drive pumps, or a second independent electrical supply that will provide sufficient power to run the system.

(j) Process equipment, filters and appurtenances, disinfection, chemical feed and storage, electrical and controls, and pipe galleries shall be located in suitable structures.

(k) All equipment not required to be in or on open basins, such as clarifier drives and flocculators, shall be located in heated, lighted, and ventilated structures.

(l) Piping shall be buried below frost level, placed in heated structures, or provided with heat and insulated.

(m) Structure entrances shall be above grade.

(n) Selected construction materials shall provide water tightness, corrosion protection, and resistance to weather variations.

(o) NSF/ANSI/CAN 61-2020/NSF/ANSI/CAN 600-2021 certified coatings used to protect structures, equipment, and piping shall be suitable for atmospheres containing moisture and low concentrations of chlorine.

(p) Surfaces exposed in chemical areas shall be protected from chemical attack.

(q) Paints shall not contain lead, mercury, or other toxic metals or chemicals.

(r) All enclosed spaces shall be provided with forced ventilation, except pumping station wetwells or clearwells that meet the following requirements:

(i) In areas where there are open treatment units exposed to the room, ventilation shall be provided to limit relative humidity to less than 85 percent but not less than six air changes per hour; and

(ii) Ventilation in electrical and equipment rooms shall limit the temperature rise in the room to less than 15 degrees Fahrenheit above ambient with at least six air changes per hour.

(s) Service transformers and other critical electrical equipment shall be located above the 100-year flood and above grade. Transformers shall be located so that they are remote or protected by substantial barriers from traffic. Motor controls shall be located in superstructures and in rooms that do not contain corrosive atmospheres.

(t) All treatment facilities shall have a flow-measuring device provided for raw water influent and clear well effluent and each shall provide totalized flow. The accuracy of the device shall be at least plus or minus two percent of span and shall meet the following requirements:

(i) Automatic controls shall be designed to permit manual override; and

(ii) The meter shall also record the instantaneous flow rate.

(u) Water treatment plants shall be provided with continuous water turbidimeters (including recorders) that demonstrate compliance with the Guidance Manual for Compliance with the Surface Water Treatment Rules, Turbidity Provisions.

Disclaimer: These regulations may not be the most recent version. Wyoming may have more current or accurate information. We make no warranties or guarantees about the accuracy, completeness, or adequacy of the information contained on this site or the information linked to on the state site. Please check official sources.
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