Utah Admin. Code 309-510-7

Current through Bulletin 2024-23, December 1, 2024

Section R309-510-7 - Source Sizing

(1) Peak Day Demand and Average Yearly Demand.

Sources shall legally and physically meet water demands under two conditions:

(a) The water system's source capacity shall be able to meet the anticipated water demand on the day of highest water consumption, which is the peak day demand.

(b) The water system's source capacity shall also be able to provide one year's supply of water, which is the average yearly demand.

(2) Indoor Water Use.

Tables 510-1 and 510-2 shall be used as the minimum sizing requirements for peak day demand and average yearly demand for indoor water use unless a public water system has obtained a reduction per R309-510-5.

TABLE 510-1 Source Demand for Indoor Use

Peak Average Type of Connection Day Demand Yearly Demand Year-round use Residential 800 gpd/conn 146,000 gal./conn Equivalent Residential Connection (ERC) 800 gpd/ERC 146,000 gal./ERC Seasonal/Non-residential use Modern Recreation Camp 60 gpd/person (See Note 1) Semi-Developed Camp a. with pit privies 5 gpd/person (See Note 1) b. with flush toilets 20 gpd/person (See Note 1) Hotel, Motel, and Resort 150 gpd/unit (See Note 1) Labor Camp 50 gpd/person (See Note 1) Recreational Vehicle Park 100 gpd/pad (See Note 1) Roadway Rest Stop 7 gpd/vehicle (See Note 1) Recreational Home Development (i.e., developments with limited water use) (See Note 2) 400 gpd/conn (See Note 1) NOTES FOR TABLE 510-1: Note 1. Average yearly demand shall be calculated by multiplying the number of days in the designated water system operating period by the peak day demand unless a reduction has been granted in accordance with R309-510-5. Note 2. To be considered a Recreational Home Development (i.e., developments with limited water use) as listed in Table 510-1, dwellings shall not have more than 8 plumbing fixture units,in accordance with the state-adopted plumbing code, and shall not be larger than 1,000 square feet. For a new not-yet-constructed development to be considered as a development with limited water use, it must have enforceable restrictions in place that are enforced by the water system or local authority and are accepted by the Director.

TABLE 510-2 Source Demand for Indoor Use - Individual Establishments(Note 1)

Type of Establishment Peak Day Demand (gpd) (Notes 2 and 3) Airports a. per passenger 3 b. per employee 15 Boarding Houses a. for each resident boarder and employee 50 b. for each nonresident boarders 10 Bowling Alleys, per alley a. with snack bar 100 b. with no snack bar 85 Churches, per person 5 Country Clubs a. per resident member 100 b. per nonresident member present 25 c. per employee 15 Dentist's Office a. per chair 200 b. per staff member 35 Doctor's Office a. per patient 10 b. per staff member 35 Fairgrounds, per person 1 Fire Stations, per person a. with full-time employees and food prep. 70 b. with no full-time employees and no food prep. 5 Gyms a. per participant 25 b. per spectator 4 Hairdresser a. per chair 50 b. per operator 35 Hospitals, per bed space 250 Industrial Buildings, per 8 hour shift, per employee (exclusive of industrial waste) a. with showers 35 b. with no showers 15 Launderette, per washer 580 Movie Theaters a. auditorium, per seat 5 b. drive-in, per car space 10 Nursing Homes, per bed space 280 Office Buildings and Business Establishments, per shift, per employee (sanitary wastes only) a. with cafeteria 25 b. with no cafeteria 15 Picnic Parks, per person (toilet wastes only) 5 Restaurants a. ordinary restaurants (not 24 hour service) 35 per seat b. 24 hour service 50 per seat c. single service customer utensils only 2 per customer d. or, per customer served (includes toilet and kitchen wastes) 10 Rooming House, per person 40 Schools, per person a. boarding 75 b. day, without cafeteria, gym or showers 15 c. day, with cafeteria, but no gym or showers 20 d. day, with cafeteria, gym and showers 25 Service Stations a. per vehicle served, or 10 b. per gas pump 250 Skating Rink, Dance Halls, etc., per person a. no kitchen wastes 10 b. Additional for kitchen wastes 3 Ski Areas, per person (no kitchen wastes) 10 Stores a. per public toilet room 500 b. per employee 11 Swimming Pools and Bathhouses, per person 10 (Note 4) Taverns, Bars, Cocktail Lounges, per seat 20 Visitor Centers, per visitor 5 NOTES FOR TABLE 510-2: Note 1. When more than one use will occur, the multiple uses shall be considered in determining total demand. Small industrial plants maintaining a cafeteria or showers and club houses or motels maintaining swimming pools or laundries are typical examples of multiple uses. Uses other than those listed above shall be considered in relation to established demands from known or similar installations. Note 2. Source capacity must at least equal the peak day demand of the system. Determine this by assuming the facility is used to its maximum , e.g., the physical capacity of the facility. Note 3. To determine the average day demand for establishments listed in Table 510-2, divide the peak day demand by 2, unless alternative data are accepted by the Director. Note 4. Or Peak Day Demand = 20 x (Water Area (ft²)/30) + Deck Area (ft²)

(3) Irrigation Use.

If a water system provides water for irrigation, Table 510-3 shall be used to determine the peak day demand and average yearly demand for irrigation water use. The following procedure shall be used:

(a) Determine the location of the water system on the map entitled Irrigated Crop Consumptive Use Zones and Normal Annual Effective Precipitation, Utah as prepared by the Soil Conservation Service (available from the Division). Find the numbered zone, one through six, in which the water system is located (if located in an area described "non-arable" find nearest numbered zone).

(b) Determine the net number of acres which may be irrigated.

(c) Refer to Table 510-3, which assumes direct application of water to vegetation, to determine peak day demand and average yearly demand for irrigation use.

(d) Consider water losses due to factors such as evaporation, irrigation delivery method, overwatering, pipe leaks, etc. Apply a safety factor to the irrigation demand in the design accordingly.

TABLE 510-3

Source Demand for Irrigation

Map Zone Peak Day Demand Average Yearly Demand (gpm/irrigated acre) (AF/irrigated acre) (Note 1) 1 2.26 1.17 2 2.80 1.23 3 3.39 1.66 4 3.96 1.87 5 4.52 2.69 6 4.90 3.26 NOTE FOR TABLE 510-3: Note 1. The average yearly demand for irrigation water use (in acre-feet per irrigated acre) is based on 213 days of irrigation, e.g., April 1 to October 31.

(4) Variations in Source Yield.

(a) Water systems shall consider that flow from sources may vary seasonally and yearly. Where flow varies, the number of service connections supported by a source shall be based on the minimum seasonal flow rate compared to the corresponding seasonal demand.

(b) Where source capacity is limited by the capacity of treatment facilities, the maximum number of service connections shall be determined using the treatment plant design capacity instead of the source capacity.

Utah Admin. Code R309-510-7

Amended by Utah State Bulletin Number 2015-15, effective 7/15/2015