DAR File No. 28422

Environmental Quality, Drinking Water

R309-550-5

Water Main Design

NOTICE OF PROPOSED RULE

DAR File No.: 28422
Filed: 12/15/2005, 01:25
Received by: NL

RULE ANALYSIS

Purpose of the rule or reason for the change:

The reason for the change is to change wording to refer to minimum water pressure described in Section R309-105-9. (DAR NOTE: The proposed amendment to Section R309-105-9 is under DAR No. 28416 in this issue.)

Summary of the rule or change:

The change makes reference to Section R309-105-9 so that minimum pressures associated with existing systems will not be confused with minimum pressures required for new Public Water Systems designed and constructed after March 1, 2006.

State statutory or constitutional authorization for this rule:

Section 19-4-104

Anticipated cost or savings to:

the state budget:

None--Since this amendment only clarifies this portion of rule and the additional water pressure requirements for new Public Water Systems, it will not require additional personnel or other funds from the state budget.

local governments:

Little to None--Most, if not all, well functioning Public Water Systems operated by local government currently meet or exceed the current minimum water pressure minimums, as well as the proposed additional minimums. The design of new Public Water Systems will only require initial planning concerning storage location and distribution pipeline sizing which should not add significant cost or time.

other persons:

Little to None--Most engineering companies currently look to typical textbook design standards, as well as standards of other agencies such as the American Water Works Association (AWWA), the American Society of Civil Engineers (ASCE), and other nearby states when designing Public Water Systems so there should not be any additional cost or time involved.

Compliance costs for affected persons:

New Public Water Systems designed and constructed after March 1, 2006, should not see any costs over and above that if their system were designed with the typical capacity for anticipated growth and expansion. Some increased cost may be expected if storage tank location for adequate pressure requires additional length of transmission line.

Comments by the department head on the fiscal impact the rule may have on businesses:

The department agrees that the proposed changes to this rule will have little to no detrimental impact on existing water systems nor on new public water systems. Dianne R. Nielson, Executive Director

The full text of this rule may be inspected, during regular business hours, at the Division of Administrative Rules, or at:

Direct questions regarding this rule to:

Bill Birkes at the above address, by phone at 801-536-4201, by FAX at 801-536-4211, or by Internet E-mail at bbirkes@utah.gov

Interested persons may present their views on this rule by submitting written comments to the address above no later than 5:00 p.m. on:

01/31/2006

This rule may become effective on:

02/01/2006

Authorized by:

Kevin Brown, Director

RULE TEXT

R309. Environmental Quality, Drinking Water.

R309-550. Facility Design and Operation: Transmission and Distribution Pipelines.

R309-550-5. Water Main Design.

(1) Distribution System Pressure.

The distribution system shall be designed to maintain [a ]minimum [pressure of 20 psi]pressures as required in R309-105-9 (at ground level) at all points of connection, under all conditions of flow, but especially during peak day flow conditions, including fire flows.

(2) Assumed Flow Rates.

Flow rates to be assumed when designing or analyzing distribution systems shall be as given in R309-510 of these rules.

(3) Computerized Network Analysis.

(a) All water mains shall be sized after a hydraulic analysis based on flow demands and pressure requirements. If the calculations needed to conduct this hydraulic analysis are complex, a computerized network analysis shall be performed to verify that the distribution system will be capable of meeting the requirements of this rule.

(b) Where improvements will upgrade more than 50% of an existing distribution system, or where a new distribution system is proposed, a hydraulic analysis of the entire system shall be prepared and submitted for review prior to plan approval.

(c) In the analysis and design of water distribution systems, the following Hazen-William coefficients shall be used: PVC pipe = 140; Ductile Iron Pipe = 120; Cement-Mortar Lined Ductile Iron Pipe = 130 to 140.

(4) Minimum Water Main Size.

For water mains not connected to fire hydrants, the minimum line size shall be 4-inch diameter. Minimum water main size serving a fire hydrant lateral shall be 8-inch diameter unless a hydraulic analysis indicates that required flow and pressures can be maintained by smaller lines.

(5) Fire Protection.

If a public water system is required to provide water for fire suppression by the local fire authority, or if the system has installed fire hydrants on existing distribution mains for that purpose:

(a) The design of the distribution system shall be consistent with Appendix [III-A and III-]B of the 2003 International[1991 Uniform] Fire Code. As specified in this code, minimum fire-flow requirements are:

(i) 1000 gpm for one- and two-family dwellings with an area of less than 3600 square feet.

(ii) 1500 gpm or greater for all other buildings.

(b) The location of fire hydrants shall be consistent with Appendix [III-B]C of the 2003 International[1991 Uniform] Fire Code. As specified in this code, average spacing between hydrants must be no greater than 500 ft.

(c) An exception to the fire protection requirements of (a) and (b) may be granted if a suitable statement is received from the local fire protection authority.

(d) Water mains not designed to carry fire flows shall not have fire hydrants connected to them.

(e) The design engineer shall verify that the pipe network design permits fire-flows to be met at representative locations while [a ]minimum pressures as required in R309-105-9 are[ of 20 psi is ] maintained at all times and at all points in the distribution system.

(f) As a minimum, the flows to be assumed during a fire-flow analysis shall be the "peak day demand" plus the fire flow requirement.

(6) Geologic Considerations.

The character of the soil through which water mains are to be laid shall be considered. This information shall accompany any submittal for a pipeline project.

(7) Dead Ends.

(a) In order to provide increased reliability of service and reduce head loss, dead ends shall be minimized by making appropriate tie-ins whenever practical.

(b) Where dead-end mains occur, they shall be provided with a fire hydrant if flow and pressure are sufficient, or with an approved flushing hydrant or blow-off for flushing purposes. Flushing devices shall be sized to provide flows which will give a velocity of at least 2.5 fps in the water main being flushed. No flushing device shall be directly connected to any sewer.

(8) Valves.

Sufficient valves shall be provided on water mains so that inconvenience and sanitary hazards will be minimized during repairs. Valves shall be located at not more than 500 foot intervals in commercial districts and at not more than one block or 800 foot intervals in other districts. Where systems serve widely scattered customers and where future development is not expected, the valve spacing shall not exceed one mile.

(9) Corrosive Soils.

The design engineer shall consider the materials to be used when corrosive soils or waters will be encountered.

(10) Special Precautions in Areas of Groundwater Contamination by Organic Compounds.

Where distribution systems are installed in areas of groundwater contaminated by organic compounds:

(a) pipe and joint materials which are not subject to permeation of the organic compounds shall be used.

(b) non-permeable materials shall be used for all portions of the system including water main, service connections and hydrants leads.

(11) Separation of Water Mains from Other Sources of Contamination.

Design engineers shall exercise caution when locating water mains at or near certain sites such as sewage treatment plants or industrial complexes. Individual septic tanks shall be located and avoided. The engineer shall contact the Division to establish specific design requirements for locating water mains near any source of contamination.

KEY: drinking water, transmission and distribution pipelines, connections, water hauling

[August 15, 2001]

Notice of Continuation September 16, 2002

19-4-104

ADDITIONAL INFORMATION

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For questions regarding the content or application of this rule, please contact Bill Birkes at the above address, by phone at 801-536-4201, by FAX at 801-536-4211, or by Internet E-mail at bbirkes@utah.gov

For questions about the rulemaking process, please contact the Division of Administrative Rules (801-538-3764). Please Note: The Division of Administrative Rules is NOT able to answer questions about the content or application of these administrative rules.