Design Guide for Community Water Systems - The Water, Sanitation ...

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7.5.2. Fire Suppression Rating Schedule.Public water supplies that provide fire protection should determine designneeded fire flow and design supply works capacity in accordance with thelatest Fire Suppression Rating Schedule published by Insurance ServicesOrganization Inc. (ISO). Ideally, design supply works capacity shouldequal or exceed design needed fire flow.7.5.3. Storage for Fire FlowStorage for fire flow is only one of many components that must beassessed in the engineering design of public water supplies’ firesuppression capability. Many other factors not related to water supply,including emergency communications capability, fire departmentcapability, building code requirements, and zoning departments, influencefire suppression capability and ISO rating. All of these factors and localfire district requirements should be assessed in the engineering design forpublic water supply facilities that will support fire suppression. Ingeneral, public water supplies with populations greater than 250 personsand with service connection densities greater than 16 service connectionsper 160 acres should consider providing at least the levels of fire flow inthe Table below.Figure 6 - Population and Fire FlowPopulationFire Flow inResidential AreasFire Flow inCommercial Areas250-999 250 gpm for 2 hours 250 gpm for 2 hours1,000 to 9,999 1000 gpm for 2 hours 2,500 gpm for 2 hours10,000 and greater 1,500 gpm for 2 hours 3,500 gpm for 3 hoursAug. 29, 2003Page 148
Chapter 8 - Dist ribution Systems8.0. Materials.8.0.1. Standards and materials selection.Pipes shall conform to the latest edition of the AWWA, ASTM, Plastic PipeInstitute (PPI), or UniBell Plastic Pipe Association standards orrecommendations. Fittings, valves, and fire hydrants shall conform to thelatest standards issued by the AWWA and shall be certified by NSF for use indrinking water. Special attention shall be given to selecting pipe materialsthat will protect against both internal and external pipe corrosion. PVC pipesthat are less than three inches in diameter must be at least Class 200 andconform to SDR-21. PVC pipes three inches through 12 inches in diametershall be no less than Class 160 and conform to SDR-26. Pipes, fittings, andappurtenances containing more than 8 percent lead shall not be used.8.0.2 Permeation of pipe walls.In areas that are contaminated with organic chemicals, permeation of organicchemicals into the water system shall be prevented by using non-permeablematerials for all portions of the water system including pipe, fittings, serviceconnections, and hydrant leads.8.0.3. Used materialsOnly water mains that been used previously for conveying potable water maybe reused, and must meet the above standards and have been practicallyrestored to their original condition.8.0.4. Joints.Packing and jointing materials used in the joints of pipe shall conform to thelatest edition of the AWWA standards. Pipe having mechanical joints orslip-on joints with rubber gaskets is preferred.8.1. Water Main Design8.1.1. Pressure.All water mains shall be sized in accordance with a hydraulic analysis basedon flow demands and pressure requirements. The system shall be designed tomaintain a minimum pressure of 35 psi at ground level at all points in thedistribution system under all conditions of design flow not including fire flow,except that the department may approve a minimum design pressure of 20 psiAug. 29, 2003Page 149
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Design GuideforCommunity Water Syst
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2.18. AUTOMATION. .................
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4.3.11. Waste Disposal. ...........
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CHAPTER 6 -- MINIMUM CONSTRUCTION R
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Maximum Hour Demand -- The amount o
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and deviations are subject to indiv
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(blank)Aug. 29, 2003Page viii
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a. A description of the nature and
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a. Hydrological data, stream flow,
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4. Be conducted under the same oper
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maintaining the new technology and
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1.2.1. Plans shall include:a. Suita
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name, number, effective date, publi
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e. The site will provide all-weathe
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chlorine residual by methods in "St
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etween them, a six-inch band of con
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a. Regulated recreational activitie
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e done to determine the degree and
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1. Pumping rate;2. Pumping water le
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sieve analyses of the water bearing
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e circulated in the annular space s
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emoved. Therefore, every well shoul
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3.2.6.4. Pitless well units.a. The
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SIZE (inches)6 id.8101214 od.161820
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Chapter 4 -- Tre atment4.0. General
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settling basins shall be not less t
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3. Shall have valves located outsid
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d. Be automatic. Timers on automati
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2. Uniformity coefficient not great
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j. During air scour, the backwash w
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. An easily readable meter or flow
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4.3.4. Design Pressure Drop or Tran
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4.3.9. Flow Meters.Totaling rate of
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utilized, shall be 1.0 milligrams p
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. Removal of precursors prior to ch
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5. Consideration shall be given to
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. Pre-treatment requirements. Iron,
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t. Housing. Bagged salt and dry bul
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4.7. Iron and Manganese ControlIron
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Where phosphate treatment is used,
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3. Series and parallel flow piping
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approval of the department before u
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contact time must be provided to co
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a. Sanitary sewers with the approva
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1. Obtain a letter of approval from
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6. The provisions for the final dis
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a. Missouri River or Mississippi Ri
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5.0.3. General equipment design.Gen
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Page 126 and 127: 5.4.2. Acids.a. Acids shall be kept
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Page 148 and 149: 6.4.2.2. Suction lines.Suction line
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Page 172 and 173: 8.6.5. Force mains.There shall be a
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