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Storage should meet peak flow requirements, equalize system pressures, and provide emergency water supply.. Water storage facili-ties are constructed within a distribution network to mee

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UFC 3-230-09A

16 January 2004

UNIFIED FACILITIES CRITERIA (UFC)

WATER SUPPLY: WATER STORAGE

APPROVED FOR PUBLIC RELEASE; DISTRIBUTION UNLIMITED

Any copyrighted material included in this UFC is identified at its point of use

Use of the copyrighted material apart from this UFC must have the permission of the

copyright holder

U.S ARMY CORPS OF ENGINEERS (Preparing Activity)

NAVAL FACILITIES ENGINEERING COMMAND

AIR FORCE CIVIL ENGINEER SUPPORT AGENCY

Record of Changes (changes are indicated by \1\ /1/)

This UFC supersedes TM 5-813-4, dated 20 September 1985 The format of this UFC does not conform to UFC 1-300-01; however, the format will be adjusted to conform at the next revision The body of this UFC is the previous TM 5-813-4, dated 20 September 1985

The Unified Facilities Criteria (UFC) system is prescribed by MIL-STD 3007 and provides

planning, design, construction, sustainment, restoration, and modernization criteria, and applies

to the Military Departments, the Defense Agencies, and the DoD Field Activities in accordance with USD(AT&L) Memorandum dated 29 May 2002 UFC will be used for all DoD projects and work for other customers where appropriate All construction outside of the United States is

also governed by Status of forces Agreements (SOFA), Host Nation Funded Construction

Agreements (HNFA), and in some instances, Bilateral Infrastructure Agreements (BIA.)

Therefore, the acquisition team must ensure compliance with the more stringent of the UFC, the SOFA, the HNFA, and the BIA, as applicable

UFC are living documents and will be periodically reviewed, updated, and made available to

users as part of the Services’ responsibility for providing technical criteria for military

construction Headquarters, U.S Army Corps of Engineers (HQUSACE), Naval Facilities

Engineering Command (NAVFAC), and Air Force Civil Engineer Support Agency (AFCESA) are responsible for administration of the UFC system Defense agencies should contact the

preparing service for document interpretation and improvements Technical content of UFC is the responsibility of the cognizant DoD working group Recommended changes with supporting rationale should be sent to the respective service proponent office by the following electronic

form: Criteria Change Request (CCR) The form is also accessible from the Internet sites listed below

UFC are effective upon issuance and are distributed only in electronic media from the following source:

• Whole Building Design Guide web site http://dod.wbdg.org/

Hard copies of UFC printed from electronic media should be checked against the current electronic version prior to use to ensure that they are current

AUTHORIZED BY:

DONALD L BASHAM, P.E

Chief, Engineering and Construction

U.S Army Corps of Engineers

DR JAMES W WRIGHT, P.E

Chief Engineer Naval Facilities Engineering Command

KATHLEEN I FERGUSON, P.E

The Deputy Civil Engineer

DCS/Installations & Logistics

Department of the Air Force

Dr GET W MOY, P.E

Director, Installations Requirements and Management

Office of the Deputy Under Secretary of Defense (Installations and Environment)

ARMY TM 5-813-4

AIR FORCE AFM 88-10, VOL 4

WATER SUPPLY, WATER STORAGE

DEPARTMENTS OF THE A R M Y A N D T H E A I R F O R C E

20 SEPTEMBER 1985

This manual has been prepared

by or for the Government and is

public property and not subject

to copyright

Reprints or republications ofthis manual should include acredit substantially as follows:

“ J o i n t D e p a r t m e n t s o f t h eArmy and Air Force USA, Tech-nical Manual TM 5-813-4/AFM88-10, Volume 4, Water Supply,Water Storage

ANDTHE AIR FORCE

WASHINGTON, DC, 20 September 1985

WATER SUPPLY, WATER STORAGE

1-1 1-2

TYPES OF STORAGE

2-1 2-2 2-3

DETERMINATION OF CAPACITY REQUIREMENTS

3-1 3-2 3-3

DESIGN AND CONSTRUCTION OF WATER

STORAGE FACILITIES

4-1 4-2 4-3 4-4 4-5

REFERENCES

TYPICAL DESIGN EXAMPLES Ôñ}

FIGURES

1-1 1-1 2-1 2-1 2-1 3-1 3-2 3-2

4-1 4-1 4-1 4-1 4-1 A-1

B-1

1-3 2-2 2-3

*This manual supersedes TM 5-813-4/AFM 88-10, Chap 4, 2 July 1958.

i

CHAPTER 1 GENERAL

1-1 Purpose

This manual provides design criteria for water

storage requirements at military facilities, gives a

typical design analysis for tanks and reservoirs,

and provides guidance on the procedures to be

fol-lowed in selecting sites for such storage works

The manual covers requirements for treated water

storage in the distribution system, but not the

storage requirements for raw water supplies or

fire deluge systems This manual is applicable to

all elements of the Army and Air Force planning

and designing water storage facilities at fixed

in-stallations

1-2 Objectives of Storage

a Flow requirements Storage should meet peak

flow requirements, equalize system pressures, and

provide emergency water supply The water supply

system must provide flows of water sufficient in

quantity to meet all points of demand in the

distri-bution system To do so, the source must produce

the required quantity and quality, pressure levels

within the distribution system must be high

enough to provide suitable pressure, and water

dis-tribution mains must be large enough to carry

these flows It is usually inefficient and

uneco-nomical to construct the treatment plant and

pumping stations sufficiently large to meet the

largest anticipated water demands A water

treat-ment plant is less efficient if flow rates through

the plant are rapidly varied Water storage

facili-ties are constructed within a distribution network

to meet the peak flow requirements exerted on the

system and to provide emergency storage

b Cost At times it is desirable to know the cost

of constructing water storage for fire protection In

such cases only the actual fire flow for the fire

period will be used in establishing the

proportion-ate share of the total cost of storage Cost of that

portion of the storage required for concurrent

do-mestic, industrial, or special demands that cannot

be curtailed during the fire period will not be

charged to fire protection

c Meeting peak flow requirements Water supply

systems must be designed to satisfy maximum

an-ticipated water demands The peak demands

usu-ally occur on hot, dry, summer days when larger

than normal amounts of water are used for

water-ing lawns and washwater-ing vehicles and equipment In

addition, most industrial processes, especially

those requiring supplies of cooling water, ence greater evaporation on hot days, thus requir-ing more water The water treatment plant canoperate at a relatively uniform rate throughoutthe day of maximum demand if enough storage isavailable to handle variations in water use Thenecessary storage can be provided in elevated,ground, or a combination of both types of storage

experi-d Distribution system pressures.

(1) System pressure requirements.

(a) Minimum pressures Water distribution

system, including pumping facilities and storagetanks or reservoirs, should be designed so thatwater pressures of at least 40 lb/in2

at groundlevel will be maintained at all points in thesystem, including the highest ground elevations inthe service area Minimum pressures of 30 lb/in2

,under peak domestic flow conditions, can be toler-ated in small areas as long as all peak flow re-quirements can be satisfied During firefightingflows, water pressures should not fall below 20 lb/

in2

at the hydrants, in new systems This ment does not constitute justification for changingexisting storage facilities solely for the purpose ofincreasing residual pressures to 20 psi Refer to

require-TM 5-813-6/AFM 88-10, Vol 6 for additionalguidance on minimum residual pressures for fireflow

(b) Maximum pressure Maximum water

pressures in distribution mains and service linesshould not normally exceed 75 lb/in2

at groundelevation Static pressures up to 100 lb/in2

can betolerated in distribution systems in small, low-lying areas Higher pressures require pressure re-ducing valves on feeder mains or individual serv-ice lines to restrict maximum service pressures to

75 lb/in2

(c) Multiple pressure levels If an extensive

area has pressures higher than 75 lb/in2

or lowerthan 40 lb/in2

under a single pressure level uration, it may be appropriate to divide the systeminto two or more separate areas, each having dif-ferent pressure levels Within each level, pressureswithin the distribution system should range from

config-40 to 75 lb/in2

at ground elevation

(2) Pressure distribution with elevated storage.

(a) Elevated storage within the distribution

system permits distribution pumps at the ment plant to operate at uniform rates

treat-1-1

(b) The usefulness of elevated storage is

shown in figure 1-1 The system illustrated in

figure 1-1 (A) (without

storage at the plant

system demand rates in

tion rate, assuming the

elevated storage) requiressufficient to provide forexcess of the plant produc-plant is operated at a uni-form rate The pump station forces water into the

service main, through which it is carried to three

load areas: A, B, and C Since all loads on the

system are met without the use of elevated

stor-age, the pump station must be capable of

supply-ing the peak rates of water use to Areas A, B, and

C, simultaneously, while maintaining the water

pressure to Area C at a sufficient level The

mini-mum recommended pressure in the distribution

system under peak nonemergency flow conditions

is 40 lb/in2

Figure l-l(B) assumes the

construc-tion of an elevated storage tank on the service

main between Areas B and C, with peak loads in

Area C and part of the peak load in Area B being

satisfied from this tank The elevation of the tank

ensures adequate pressures within the system The

storage in the tank is replenished when water

de-mands are low and the pump station can fill the

tank while still meeting all flow and pressure

re-quirements in the system The figure 1-1 (B)

ar-rangement reduces required capacity of the

distri-bution pumps

(c) Most elevated storage

the distribution system That is,

tanks “float” onthe elevated tank

is hydraulically connected to the distributionsystem, and the volume of water in the tank tends

to maintain system pressures at a uniform level.When water use is high and pumping facilitiescannot maintain adequate pressures, water is dis-charged from elevated tanks Conversely, whenwater use is low, the pumps, which operate within

a reasonably uniform head-capacity range, supplyexcess water to the system and the elevated stor-age is refilled

e Provision of emergency water supplies.

at any time, but may well coincide with otherlarge water demands on the system Necessaryflows for firefighting purposes are as given in TM5-813-6/AFM 88-10, Vol 6, and TM 5-813-7/AFM88-10, Vol 7 Storage and distribution facilitieswill include capacity for required firefighting flows

at adequate pressures at any point of the tion

installa-(2) Other emergencies Water storage must

pro-vide an emergency supply of water in the eventthe water treatment plant, distribution pumps, or

a principal transmission main is out of service.The amount of emergency storage required de-pends on the reliability of the system and theextent of other safeguards incorporated into thesystem, i.e., finished water interconnections with amunicipality (for either normal or emergency use)

1 - 2

( B ) W A T E R F L O W S A N D P R E S S U R E S W I T H E L E V A T E D

WATER PRESSURE

WATER

STORAGE

1 - 3

TYPES OF

2-1 General

Required storage capacity at military installations

is met by use of elevated or ground storage

Ele-vated storage, feeds the water distribution system

by gravity flow Storage which must be pumped

into the system is generally in ground storage

tanks Clearwell storage, which is usually part of a

water treatment plant, is not included in

comput-ing storage unless sufficient firm pumpcomput-ing

capac-ity is provided to assure that the storage can be

utilized under emergency conditions, and then

only to the extent of storage in excess of the

24-hour requirements of the treatment plant

Clear-well storage is used to supply peak water demand

rates in excess of the production rate, and to

pro-vide a reservoir for plant use, filter backwash

supply, and water supply to the system for short

periods when plant production is stopped because

of failure or replacement of some component or

unit of treatment

2-2 Ground Storage

a General Ground storage is usually located

—

remote from the treatment plant but within the

distribution system Ground storage is used to

reduce treatment plant peak production rates and

also as a source of supply for repumping to a

higher pressure level Such storage for repumping

is common in distribution systems covering a large

area, because the outlying service areas are

beyond the range of the primary pumping

facili-ties

b Type Ground storage tanks or reservoirs,

below ground, partially below ground, or

con-structed above ground level in the distribution

system, may be accompanied by pump stations if

not built at elevations providing the required

system pressure by gravity However, if the

ter-rain permits, this design location of ground tanks

at elevation sufficient for gravity flow is preferred

Concrete reservoirs are generally built no deeper

than 20-25 feet below ground surface If rock is

present, it is usually economical to construct the

storage facility above the rock level In a single

pressure level systems, ground storage tanks

should be located in the areas having the lowest

system pressures during periods of high water use

In multiple pressure level systems, ground storage

tanks are usually located at the interface between

pressure zones with water from the lower pressure

STORAGEzones filling the tanks and being passed to higherpressure zones through adjacent pump stations

2-3 Elevated Storage

a General Elevated storage is provided within

distribution system to supply peak demand ratesand equalize system pressures In general, elevatedstorage is more effective and economical thanground storage because of the reduced pumping re-quirements, and the storage can also serve as asource of emergency supply since system pressurerequirements can still be met temporarily whenpumps are out of service

b Type The most common types of elevatedstorage are elevated steel tanks, and standpipes

An example of a conventional elevated steel tank

is given in figure 2–1 In recent years, elevatedtanks supported by single pedestals, such as shown

in figure 2–2, have been constructed where

esthet-ic considerations are an important part of thedesign process (See American Water Works Asso-ciation D100, Standard for Welded Steel Tanks forWater Storage (app A).)

c Standpipe A standpipe is a tall cylindricaltank normally constructed of steel or reinforcedconcrete Only the portion of the storage volume of

a standpipe that meets the requirements of d

below is considered useful storage for pressureequalization purposes The lower portion of thestorage acts to support the useful storage and toprovide a source of emergency water supply

d Elevated storage Elevated storage tanks

should be located in the areas having the lowestsystem pressures during intervals of high wateruse to be effective in maintaining adequate systempressures and flows during periods of peak waterdemand These are those of greatest water demand

or those farthest from pump stations Elevatedtanks are generally located at some distance fromthe pump station(s) serving a distribution pressurelevel, but not outside the boundaries of the servicearea, unless the facility can be placed on a nearbyhill Additional considerations for siting of elevat-

ed storage are conditions of terrain, suitability ofsubsurface soil and/or rock for foundation pur-poses, and hazards to low-flying aircraft Elevatedtanks are built on the highest available ground, up

to static pressures of 75 lb/in 2

in the system, so as

to minimize the required construction cost andheights

2-1