DAR File No. 28419

Environmental Quality, Drinking Water

R309-510-9

Distribution System Sizing

NOTICE OF PROPOSED RULE

DAR File No.: 28419
Filed: 12/15/2005, 01:24
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.

R309-510. Facility Design and Operation: Minimum Sizing Requirements.

R309-510-9. Distribution System Sizing.

(1) General Requirements.

The distribution system shall be designed to insure that [a ]minimum [of 20 psi exists]water pressures as required in R309-105-9 exist at all points within the system[ during peak instantaneous demand conditions]. If the distribution system is equipped with fire hydrants, the Division will require a letter from the local fire authority stating the fire flow and duration required of the area to insure the system shall be designed [to insure that a minimum of 20 psi exists]to provide minimum pressures as required in R309-105-9 to exist at all points within the system when needed fire flows are imposed upon the peak day demand flows of the system.

(2) Indoor Use, Estimated Peak Instantaneous Demand.

(a) For community water systems and large non-community systems, the peak instantaneous demand for each pipeline shall be assumed for indoor use as:

Q = 10.8 x N^0.64

where N equals the total number of ERC's, and Q equals the total flow (gpm) delivered to the total connections served by that pipeline.

For Recreational Vehicle Parks, the peak instantaneous flow for indoor use shall be based on the following:

TABLE 510-6

Peak Instantaneous Demand for Recreational Vehicle Parks



Number of Connections                     Formula

      0 to 59                             Q = 4N

     60 to 239                            Q = 80 + 20N0.5

    240 or greater                        Q = 1.6N



     NOTES FOR TABLE 510-6:

     Q is total peak instantaneous demand (gpm) and N is the

maximum number of connections.  However, if the only water use

is via service buildings the peak instantaneous demand shall

be calculated for the number of fixture units as presented in

Appendix E of the 2000 International Plumbing Code.

(b) For small non-community water systems the peak instantaneous demand to be estimated for indoor use shall be calculated on a per-building basis for the number of fixture units as presented in Appendix E of the 2000 International Plumbing Code.

(3) Outdoor Use, Estimated Peak Instantaneous Demand.

Peak instantaneous demand to be estimated for outdoor use is given in Table 510-7. The procedure for determining the map zone and irrigated acreage for using Table 510-7 is outlined in Section R309-510-7(3).

TABLE 510-7

Peak Instantaneous Demand for Outdoor Use



Map Zone                      Peak Instantaneous Demand

                                 (gpm/irrigated acre)

   1                                     4.52

   2                                     5.60

   3                                     6.78

   4                                     7.92

   5                                     9.04

   6                                     9.80

(4) Fire Flows.

(a) Distribution systems shall be designed to deliver needed fire flows if fire hydrants are provided. The design engineer shall consult with the local fire suppression authority regarding needed fire flows in the area under consideration. This information shall be provided to the Division. Where no local fire suppression authority exists, needed fire flows shall be assumed to be 1000 gpm unless the local planning commission provides a letter indicating that the system will not be required to provide any fire flows, in which case fire hydrants will not be allowed to be installed on any mains.

(b) If a distribution system is equipped with fire hydrants, the system shall be designed to insure that [a ]minimum pressures required by R309-105-9 exist[of 20 psi exists] at all points within the system when fire flows are added to the peak day demand of the system. Refer to Section R309-510-7 for information on determining the peak day demand of the system.

KEY: drinking water, minimum sizing, water conservation

[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.