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

More documents

Recommendations

Info

fluoride feed line when a metering pump is used. These antisiphondevices should have a diaphragm that is spring-loaded in the closedposition. One device should be located at the fluoride injection pointand one device shall be located at the metering pump head on thedischarge side. Metering pump antisiphon devices should be selectedto provide the backpressure required by the pump manufacturer.8. Operation of a fluoridation system without a functional antisiphondevice can lead to an overfeed that exceeds 4 mg/L. Therefore,maintenance manuals, tools and repair parts must be provided to thesystem operators so that all antisiphon devices can be dismantled andvisually inspected at least once a year. Schedules of repairs orreplacements should be based on the manufacture's recommendations.Equipment for semiannual vacuum testing of all antisiphon devicesshould be provided.9. Fluoride metering pumps should be located on a shelf not more than 4feet (1.2 m) higher than the lowest normal level of liquid in the carboy,day tank, or solution container. A flooded suction line is notrecommended in water fluoridation.10. For greatest accuracy, metering pumps should be sized to feed fluoridenear the midpoint of their range. Pumps should always operatebetween 30%-70% of capacity. Metering pumps that do not meet thesesize specifications should not be installed. Oversized metering pumpsshould not be used because serious overfeeds (i.e., an overfeed thatexceeds 4 mg/L) can occur if they are set too high. Conversely,undersized metering pumps can cause erratic fluoride levels.11. Priming switches on the metering pumps shall be spring-loaded toprevent pumps from being started erroneously with switches in thepriming position.12. Flow meter-paced systems should not be installed unless the rate ofwater flow past the point of fluoride injection varies by more than20%.13. A master meter on the water service line must be provided so thatcalculations can be made to confirm that the proper amounts offluoride solution are being fed.14. Fluoride solutions shall not be injected in a point of negative pressure.15. The fluoride feed line(s) should be either color-coded, when practical,or clearly identified by some other means. Color-coding helps preventpossible errors when taking samples or performing maintenance. Thepipes for all fluoride feed lines should be painted light blue with redbands. The word "fluoride" and the direction of the flow should beprinted on the pipe or, for small piping, on the wall beside the pipe.16. The dilution water pipe shall end at least two pipe diameters above thehighest water level in the solution tank, or an adequate backflowprevention device must be provided. All hose connections withinreach of the fluoride feed equipment should be provided with a hosebibvacuum breaker.Aug. 29, 2003Page 114
17. Cross-connection controls must be provided that conforms to stateregulations in 10 CSR 60-11.010.18. Hose bibs and water supply piping to supply potable water for clean upof spills shall be provided in both the chemical feed and storage areas.The number of hose bibs and their location depend upon the size of theareas served.c. Sodium Fluoride Saturator Systems. Sodium fluoride systems are notrecommended but may be considered on a case-by-case basis with thedepartment’s written approval.d. Fluorosilicic Acid Systems.1. To reduce the hazard to the water plant operator, fluorosilicic acid(hydrofluosilicic acid) must not be diluted. Instead, the metering pumpspecified shall permit the use of undiluted fluorosilicic acid for waterplants of any size.2. No more than a 30-hour supply of fluorosilicic acid should beconnected at any time to the suction side of the chemical feed pump.All systems using bulk storage tanks must have a day tank.3. Day tanks or direct acid-feed carboys/drums shall be located on scales;daily weights shall be measured and recorded. Volumetricmeasurements, such as marking the side of the day tank, are notadequate for monitoring acid feed systems.4. Full spill containment shall be provided for bulk storage tanks.Furthermore, bulk storage facilities cannot be located over planttreatment basins, pumping wells, transfer wells or clearwells.5. Bulk storage tanks inside buildings; day tanks and unsealed carboysshall be vented to the outside with a vent approved by the department.e. Dry Fluoride Feed Systems.1. Dry feeders (both volumetric and gravimetric) must be provided with asolution tank.2. Solution tanks shall be sized according to Water Fluoridation: AManual for Engineers and Technicians published by the Centers forDisease Control and Prevention.3. A mechanical mixer should be used in every solution tank of a dryfeeder when sodium fluorosilicate is used.4. Scales must be provided for weighing the amount of chemicals used inthe dry feeder.f. Testing Equipment.1. Surface water plants should use the ion electrode method of fluorideanalysis.2. A magnetic stirrer should be used in conjunction with the ion electrodemethod of fluoride analysis.3. The colorimetric method (SPADNS) of fluoride analysis can be usedwhere no interference occurs or where the interferences are consistent(e.g., from iron, chloride, phosphate, sulfate, or color).g. Secondary controls. Secondary control systems for fluoride chemical feeddevices may be required by the department as a means of reducing theAug. 29, 2003Page 115
Page 1:
Design GuideforCommunity Water Syst
Page 4 and 5:
2.18. AUTOMATION. .................
Page 6 and 7:
4.3.11. Waste Disposal. ...........
Page 8:
CHAPTER 6 -- MINIMUM CONSTRUCTION R
Page 12 and 13:
Maximum Hour Demand -- The amount o
Page 14 and 15:
(This page is intentionally blank.)
Page 16 and 17:
and deviations are subject to indiv
Page 18 and 19:
(blank)Aug. 29, 2003Page viii
Page 20 and 21:
a. A description of the nature and
Page 22 and 23:
a. Hydrological data, stream flow,
Page 24 and 25:
4. Be conducted under the same oper
Page 26 and 27:
maintaining the new technology and
Page 28 and 29:
1.2.1. Plans shall include:a. Suita
Page 30 and 31:
name, number, effective date, publi
Page 32 and 33:
Page 34 and 35:
e. The site will provide all-weathe
Page 36 and 37:
chlorine residual by methods in "St
Page 38 and 39:
etween them, a six-inch band of con
Page 40:
Page 46 and 47:
a. Regulated recreational activitie
Page 48:
e done to determine the degree and
Page 51:
1. Pumping rate;2. Pumping water le
Page 55 and 56:
sieve analyses of the water bearing
Page 57 and 58:
e circulated in the annular space s
Page 59 and 60:
emoved. Therefore, every well shoul
Page 61 and 62:
3.2.6.4. Pitless well units.a. The
Page 63 and 64:
SIZE (inches)6 id.8101214 od.161820
Page 65 and 66:
Chapter 4 -- Tre atment4.0. General
Page 67 and 68:
settling basins shall be not less t
Page 69 and 70:
3. Shall have valves located outsid
Page 71:
d. Be automatic. Timers on automati
Page 76 and 77:
2. Uniformity coefficient not great
Page 78 and 79:
j. During air scour, the backwash w
Page 80 and 81:
. An easily readable meter or flow
Page 82 and 83: 4.3.4. Design Pressure Drop or Tran
Page 84 and 85: 4.3.9. Flow Meters.Totaling rate of
Page 86 and 87: utilized, shall be 1.0 milligrams p
Page 88 and 89: . Removal of precursors prior to ch
Page 90 and 91: 5. Consideration shall be given to
Page 92 and 93: . Pre-treatment requirements. Iron,
Page 94 and 95: t. Housing. Bagged salt and dry bul
Page 96 and 97: 4.7. Iron and Manganese ControlIron
Page 98 and 99: Where phosphate treatment is used,
Page 100 and 101: 3. Series and parallel flow piping
Page 102 and 103: approval of the department before u
Page 104 and 105: contact time must be provided to co
Page 106 and 107: a. Sanitary sewers with the approva
Page 108 and 109: 1. Obtain a letter of approval from
Page 110 and 111: 6. The provisions for the final dis
Page 112 and 113: a. Missouri River or Mississippi Ri
Page 114 and 115: 5.0.3. General equipment design.Gen
Page 116 and 117: minimize chemical dust created by t
Page 118 and 119: 1. At least 30 days of chemical sup
Page 120 and 121: e. Hand pumps shall be provided for
Page 122 and 123: 5.2. Chemicals.5.2.1 Shipping conta
Page 124 and 125: outside atmosphere, above grade and
Page 126 and 127: 5.4.2. Acids.a. Acids shall be kept
Page 128 and 129: 4. Anhydrous ammonia contact with c
Page 130 and 131: combustible material.2. Powdered ac
Page 134 and 135: possibility for overfeed.h. Protect
Page 136 and 137: caution.d. Where taste and odor con
Page 138 and 139: e installed to monitor the flow of
Page 140 and 141: the generator dielectrics. Sufficie
Page 142 and 143: published by the National Fire Prot
Page 144 and 145: g. Water from pump gland drainage s
Page 146 and 147: 6.3. Pumps.6.3.1.Pumps shall be siz
Page 148 and 149: 6.4.2.2. Suction lines.Suction line
Page 150 and 151: cessation of minimum essential serv
Page 152 and 153: parameters: average winter (Decembe
Page 154 and 155: a. Overflows shall be sized to perm
Page 156 and 157: additional shielding to prevent the
Page 158 and 159: largest pump out of service shall b
Page 160 and 161: 7.1.4. CostsAs part of the final en
Page 162 and 163: 7.4. Hydropneumatic Storage7.4.1. H
Page 164 and 165: provided on larger tanks as needed
Page 166 and 167: 7.5.2. Fire Suppression Rating Sche
Page 168 and 169: in areas served by rural water dist
Page 170 and 171: connected directly to any sewer. Su
Page 172 and 173: 8.6.5. Force mains.There shall be a
Page 174: 8.11.2. Filling device.A filling de
show all

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

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?