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

More documents

Recommendations

Info

5.0.3. General equipment design.General equipment design shall be such that:a. Feeders will be able to supply, at all times, the necessary amounts ofchemicals at an accurate rate throughout the range of feed;b. Chemical-contact materials and surfaces are resistant to the aggressivenessof the chemical solution;c. Corrosive chemicals are introduced in such a manner as to minimizepotential for corrosion and damage to water piping, treatment basins, andthe water treatment facilities;d. Chemicals that are incompatible are not fed, stored, or handled together;e. All chemicals are conducted from the feeder to the point of application inseparate conduits;f. Chemical feeders are as near as practical to the feed point;g. Chemical feeders and pumps operate at no lower than 20 percent of thefeed range;h. Chemicals are fed by gravity where practical; andi. Adequate space is provided around each chemical feeder to safely load,operate, clean, and maintain each feeder.5.1. FACILITY DESIGN.5.1.1. Number of feeders.a. Where chemical feed is necessary for the production of safe drinking water,such as chlorination, coagulation, or other essential processes:1. A minimum of two feeders shall be provided or a standby unit or acombination of units of sufficient capacity shall be available to replacethe largest unit during shut-downs; and2. Where a booster pump or a transfer pump is required, duplicateequipment shall be provided and, when necessary, standby power.b. A separate feeder shall be used for each chemical applied and should beused for each application point. Only one solution pump should draw froma solution tank, day tank, barrel, or carboy.c. Spare parts shall be available for all feeders to replace parts that aresubject to wear and damage.5.1.2. Control.a. Feeders may be manually or automatically controlled. Automatic controlsshall be designed to allow override by manual controls and to allowadjustment of each control parameter.b. When automatic controls are used, they shall include devices that preventfeeders from operating unless water is being produced.c. When automatic controls are used, they shall include devices so thatchemical feed rates shall be proportional to flow.Aug. 29, 2003Page 96
d. A means to measure all appropriate water flows must be provided in orderto determine chemical feed rates.e. Provision shall be made for measuring the volume or weight of chemicalsused.f. Weighing scales:1. Shall be provided for weighing all active gas cylinders at all plantsutilizing chlorine gas, carbon dioxide, or ammonia gas. Scales forweighing all gas cylinders smaller than one ton in size shall be lowprofile for ease in manually loading cylinders onto the scales.Otherwise, electric hoists, hoist tracks, and properly sized cylinderclamps shall be provided;2. May be required for fluoride solution feed;3. Shall be provided for each active chemical solution day tank;4. Shall be provided for each solution or emulsion fed from carboys orbarrels;5. Shall be provided to weigh chemicals when making batches ofchemical feed solutions;6. Should be provided for volumetric dry chemical feeders;7. Should be accurate to measure increments of 0.5 per cent of load; and8. Totaling gas meters shall be provided to measure all gas chemicals fedfrom rail cars or bulk storage containers.5.1.3. Dry chemical feeders.Dry chemical feeders shall:a. Measure chemicals volumetrically or gravimetrically;b. Provide adequate solution water and agitation of the chemical in thesolution pot;c. Provide gravity feed from solution pots where possible;d. Completely enclose chemicals to prevent emission of dust to the operatingroom;e. Be located and designed to prevent lifting injuries when loading sacks ofchemical into the feeder. The current OSHA or National Institute ofOccupational Safety and Health (NIOSH) guidance for manual liftingshould be followed;f. Provide adequate space around each feeder to allow chemical pallets to bemoved close to the feeder and minimize the distance that chemical bags orcontainers must be carried;g. Have chemical hoppers sized to minimize loading frequencies to no morethan once per eight-hour shift;h. Not have bulk storage facilities that feed directly into the feed chamber buthave a chemical hopper on the feeder that is large enough to minimizechemical fluidization;i. Have vibrators and anti-bridging and caking equipment that is separatefrom those provided on the bulk storage facilities;j. Have feeder shells and housings constructed of stainless steel, aluminumor a nonmetallic substance that fully enclose the chemical being fed toAug. 29, 2003Page 97
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 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 132 and 133: fluoride feed line when a metering
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?