U.S. Department of the Interior USGS Fact Sheet 174-99

U.S. Geological Survey February 2000

Commonwealth of Pennsylvania

Department of Environmental Protection,

Office of Water Quality Management

ESTIMATED WATER WITHDRAWALS AND USE IN PENNSYLVANIA, 1995

HOW DO WE USE WATER?

In practical terms, water use is divided into

two basic types: instream use and offstream

use. Instream use is water used in its natural

channel, basin, or behind a dam and includes

activities such as fishing, boating, and other

recreational activities. Instream use also

includes hydroelectric power generation. Offstream use is water pumped or diverted from

its natural channel, basin, or aquifer. Offstream uses are divided into the following

categories: public supply, domestic, commercial, industrial, thermoelectric power, mining,

livestock, and irrigation. This fact sheet provides an overview of offstream and hydroelectric power water use in Pennsylvania. It

describes water withdrawals by source, water

withdrawals and deliveries by category,

changes in water use over time, and watermanagement responsibilities in the State.

HOW DO WE GET WATER?

Water users obtain water from groundwater or surface-water sources. Those who

withdraw water for their own use are classified

as self-supplied. Water used for mining, livestock, irrigation, and thermoelectric power and

hydroelectric power generation is typically

self-supplied. Other water users obtain water

from deliveries by public suppliers; these users

are classified as public-supplied. Domestic,

commercial, and industrial water users can be

self-supplied, public-supplied, or both.

HOW MUCH WATER IS USED

IN PENNSYLVANIA?

In 1995, Pennsylvania ranked 12th among

the states with a total freshwater withdrawal of

9,610 Mgal/d (fig. 1). Of this amount, 91 percent (8,800 Mgal/d) was from surface water

and 9 percent (810 Mgal/d) was from ground

water. Withdrawals for thermoelectric power

generation totaled 5,930 Mgal/d, the largest

offstream use of water in Pennsylvania. Industrial (1,680 Mgal/d) and public supply

(1,550 Mgal/d) were the fourth and sixth largest withdrawals of their type in the nation (Solley and others, 1998). Mining withdrawals

were 182 Mgal/d. Domestic, livestock, commercial, and irrigation withdrawals were 181,

55.3, 29.6, and 15.9 Mgal/d, respectively.

The largest overall use of water was for

hydroelectric power generation, an instream

use. The amount of water used for hydroelectric power generation, 55,900 Mgal/d, was

more than five times greater than all offstream

uses combined.

Mgal/d, or million gallons per day, and

gpcd, or gallons per capita per day, are

units of measure applied to water-use

data. Withdrawals are the removal of

water, through pumping or diversion, from

ground-water or surface-water sources.

Public-supply deliveries are the transfer

of water to a point of use.

Figure 1. Self-supplied withdrawals and public-supply deliveries in Pennsylvania, by water source and category of use, 1995.

(All values in million gallons per day. Values may not add up to totals because of independent rounding.)
PUBLIC SUPPLY—

Water Withdrawn, Treated, and Delivered

to Other Uses

Pennsylvania has about 2,160 public suppliers or community water systems. A public

supplier is any water system that serves 25 or

more people at their primary residence or has

15 or more service connections. Public suppliers withdrew about 1,550 Mgal/d in 1995

(fig. 1), 16 percent from ground-water sources

and 84 percent from surface-water sources.

More than nine million Pennsylvania residents

were served by public suppliers in 1995. Statewide, increased deliveries for domestic and

commercial uses since 1985 (52.3 Mgal/d)

have offset decreased deliveries for industrial

use (-53.2 Mgal/d). Per-capita withdrawals1 by

public suppliers have decreased from 196 gpcd

in 1985 to 189 gpcd in 1990 and to 171 gpcd

in 1995. Public suppliers delivered nearly half

of the water used for domestic, commercial,

and industrial uses in the Delaware and Susquehanna River Basins (fig. 2). A comparison

of public-supply data since 1985, by river

basin, showed total deliveries increased 5 to

6 percent in the Delaware and Susquehanna

River Basins due to increased deliveries for

domestic and commercial uses, and decreased

about 15 percent in the Ohio River Basin

because of reduced deliveries for domestic and

industrial uses.

DOMESTIC—

Water Use in and Around Your Home

Domestic water use includes water used for

cooking, bathing, laundry, toilet flushing, lawn

watering, pool filling, car washing, and other

residential uses. Water used for domestic purposes is either self-supplied or is delivered by

public suppliers, or both. Self-supplied domestic withdrawals in 1995 were estimated to be

181 Mgal/d (fig. 1). In Pennsylvania, self-supplied domestic water is entirely from ground

water and constitutes the third largest domestic

withdrawals among the states (Solley and others, 1998). Public-supply deliveries for domestic uses (559 Mgal/d) were triple that of selfsupplied withdrawals. Statewide, domestic

per-capita use (public-supplied)2 decreased

from 66 to 62 gpcd between 1985 and 1995.

Domestic per-capita use (public-supplied) rose

from 56 to 67 gpcd in the Delaware River

Basin, decreased from 76 to 57 gpcd in the

Ohio River Basin, and decreased from 76 to

58 gpcd in the Susquehanna River Basin.

The self-supplied population was estimated

to be the difference between the 1995 census

population data and the population reported to

be served by public suppliers, county by

county. Domestic use was estimated at

60 gpcd for the self-supplied population3

(William Gast, Pennsylvania Department of

Environmental Protection, oral commun.,

1998) and averaged 62 gpcd (statewide) for

public-supplied population (unpub. data on

file, Lemoyne, Pa., U.S. Geological Survey,

1998). The national averages for domestic use

for self-supplied and public-supplied populations were 80 and 101 gpcd, respectively (Solley and others, 1998, p. 27).

COMMERCIAL & INDUSTRIAL—

Water Use at Your Workplace

Water used in retail stores and malls,

educational institutions, health care and correctional facilities, business and government

offices, public and private parks and recreational facilities, and military bases constitutes

commercial and institutional water use. In

1995, self-supplied commercial withdrawals

were 29.6 Mgal/d; public-supply deliveries to

commercial activities were 218 Mgal/d (fig.

1). Statewide, commercial use increased from

214 to 247 Mgal/d between 1985 and 1995. A

comparison of commercial use since 1985 by

river basin showed little net change in the Delaware River Basin between 1985 and 1995

because decreases in withdrawals were offset

by public-supply deliveries. During the same

period, commercial use in the Ohio River

Basin increased from 49.3 to 67.2 Mgal/d, and

commercial use in the Susquehanna River

Basin increased from 54.4 to 68.8 Mgal/d.

Industrial water use is water used for

manufacturing processes, especially washing

and cooling. In 1995, industrial withdrawals

were about 1,680 Mgal/d and public-supplied

deliveries to industry were about 193 Mgal/d.

Statewide, industrial use decreased from 2,300

to 1,870 Mgal/d between 1985 and 1995. In

the Delaware River Basin, industrial use was

464 Mgal/d or a little more than half the 1985

amount of 899 Mgal/d. Public-supply deliveries to industry in the Ohio River Basin have

decreased from 86.0 to 65.5 Mgal/d. In the

Susquehanna River Basin, industrial use

1

 Total withdrawals made by public suppliers,

divided by the public suppliers’ total population

served.

2

Deliveries by public suppliers to domestic use

divided by the public suppliers’ total population

served.

3

The 60 gpcd value used for the 1995 estimation

was an increase from 50 gpcd used in the 1985 and

1990 estimates.

Figure 2. Public-supply deliveries and self-supplied withdrawals in Pennsylvania’s three

major river basins. The amounts include deliveries and withdrawals in adjacent river basins

to the extent the basins are within the borders of the Commonwealth. Pie charts indicate

percentages of water use within each area.
decreased from 256 Mgal/d in 1985 to

241 Mgal/d in 1995. Industrial consumptive

use (water incorporated into a product or evaporated to the atmosphere) totaled about

158 Mgal/d in 1995, about 28 Mgal/d less than

in 1985.

HYDROELECTRIC & THERMOELECTRIC—

Water for Power

Water use for hydroelectric power is distinct from other water use because water flowing through a dam is considered an instream

use rather than a withdrawal. In 1995, water

use for hydroelectric power generation was

84 percent of total use or about 55,900 Mgal/d.

The 1995 hydroelectric water use is lower than

the 60,700 Mgal/d used in 1985 and the

68,000 Mgal/d used in 1990. Pumped storage,

a variation of hydroelectric power generation,

generates power during hours of peak power

demand. Pumped storage facilities are typically considered an instream use of water,

although there are exceptions. Pennsylvania

has eight hydroelectric sites; two are pumped

storage hydroelectric power-generation sites.

Hydroelectric power facilities generated less

than 1 percent of all electric power generated

in the state in 1995.

In contrast, water used for thermoelectric

power generation is an offstream use because

water is either pumped or diverted from a

ground-water or surface-water source.

In 1995, fossil-fuel power plants withdrew

6.21 Mgal/d of ground water and

3,870 Mgal/d of surface water. Nuclear

power plants withdrew 2,050 Mgal/d of surface water. Thermoelectric (combined fossilfuel and nuclear) power withdrawals were

42 percent less than in 1985 (10,200 Mgal/d).

Consumptive use by thermoelectric power

increased from 193 Mgal/d in 1985 to

239 Mgal/d in 1995.

MINING—

Water to Process Raw Materials

Mining water use includes water used for

the extraction of coals and ores, crude petroleum, and gases; it also includes water use

associated with quarrying, especially milling

(crushing, screening, washing, and flotation),

equipment cleaning, and dust control. Water

use in this category does not include dewatering, unless the water is put to a specific use

before it is discharged. In 1995, mining

ground-water withdrawals were 161 Mgal/d,

and mining surface-water withdrawals were

20.8 Mgal/d (fig. 1). Statewide, mining use

increased from 148 Mgal/d in 1985 to

252 Mgal/d in 1990 and decreased to

182 Mgal/d in 1995. A comparison of mininguse data since 1985, by river basin, showed the

Delaware, Ohio, and Susquehanna River

Basins had large increases in withdrawals

between 1985 and 1990. Since 1990, withdrawals in the Delaware and Ohio River

Basins decreased to about 9 percent below the

1985 withdrawal amounts. In the Susquehanna

River Basin, mining use increased from 50.0

to 108 Mgal/d between 1985 and 1990 and

decreased to 93.0 Mgal/d in 1995.

LIVESTOCK & IRRIGATION—

Water to Raise Food

Livestock water use includes water used in

two sub-categories: stock (production of red

meat, milk, poultry, eggs, and wool) and animal specialties (fur-bearing animals, horses

and other equines, and animal aquaculture).

Withdrawals for livestock water use were estimated by multiplying the number of animals

(U.S. Bureau of Census, 1994a, 1994b; Pennsylvania Department of Agriculture, 1996) by

the coefficients of water use per animal unit in

the state water plan (Pennsylvania Department

of Environmental Resources, 1975). For 1995,

freshwater withdrawals for livestock were estimated to be 55.3 Mgal/d (fig. 1). Groundwater withdrawals for livestock were estimated to be 48.2 Mgal/d, and surface-water

withdrawals were estimated to be 7.09 Mgal/d.

Livestock use was estimated to be 70.4 Mgal/d

in 1985 and 53.1 Mgal/d in 1990, a decrease of

24 percent. Since 1985, withdrawals of water

for livestock in the Susquehanna River Basin

increased from 66 to 73 percent of statewide

withdrawals for livestock. Withdrawals for

livestock in the Delaware River Basin

decreased from 13 to 11 percent and in the

Ohio River Basin from 21 to 16 percent of

statewide withdrawals for livestock.

Irrigation water use includes water applied

to crops to promote plant growth or to provide

protection from freezing. Sprinkler (spray)

irrigation is the predominant method of water

application in Pennsylvania, although other

methods are available. Micro-irrigation is

becoming more widely utilized for horticultural specialities and selected fruit and vegetable crops. Irrigation water use in 1995 was

estimated to be about 15.9 Mgal/d (fig. 1). Irrigation data (U.S. Bureau of Census, 1994a)

were utilized to make estimates of the amount

of water applied, method of application, water

source, and acres irrigated. Irrigated acreage

accounted for only 0.6 percent of total harvested acreage in the state. Irrigation withdrawals were about 10.7 Mgal/d in 1985 and

increased to 14.3 Mgal/d by 1990. A comparison of irrigation water-use data, by river basin,

showed that between 1985 and 1990, withdrawals in the Delaware River Basin increased

from 2.31 to 3.12 Mgal/d, and withdrawals in

the Ohio River Basin increased from 1.68 to

2.37 Mgal/d. Between 1990 and 1995, withdrawals in the Delaware River Basin increased

to 3.56 Mgal/d; withdrawals in the Ohio River

Basin returned to 1.64 Mgal/d. Irrigation withdrawals in the Susquehanna River Basin

increased from 6.75 to 10.7 Mgal/d between

1985 and 1995 or from 63 to 67 percent of

statewide irrigation withdrawals.

WATER MANAGEMENT

IN PENNSYLVANIA

The monitoring of water withdrawals in

Pennsylvania is shared among the state and

two river-basin commissions formed as federal-state compacts. The Pennsylvania Department of Environmental Protection (DEP)

regulates surface-water withdrawals for public supply and provides overall supervision of

all public suppliers in Pennsylvania. The federal-state compact agencies are the Delaware

River Basin Commission (DRBC) and the

Susquehanna River Basin Commission

(SRBC). The DRBC and SRBC have authority

in their respective basins to register all groundwater withdrawals greater than 10,000 gpd

(gallons per day) and review all surface-water

withdrawals greater than 100,000 gpd.

In administering the Water Rights Act of

June 24, 1939, the DEP reviews applications

for surface-water withdrawals by public suppliers to ensure that new or expanded withdrawals:

• Will not conflict with water rights held

by any other public supplier,

• Is reasonably necessary for the present

purposes or future needs of the public

supplier making the application,

• Will not interfere with navigation,

• Will not jeopardize public safety, and

• Will not cause substantial injury to the

Commonwealth.

Instream uses downstream of public watersupply intakes are protected by permit conditions requiring either conservation releases

from large reservoirs or minimum passby

flows below small reservoirs, intake dams, or

other intake structures. Conservation releases

must be maintained at all times, regardless of

inflow to the reservoir, and are therefore provided from the storage in the reservoir. Passby

flows are minimum flow quantities that must

be allowed to pass the intake structure. When

inflows are inadequate to provide for the

passby and the withdrawal, the withdrawal

must be either reduced or discontinued to

allow the passby quantity or natural inflow to

pass the intake.

Pennsylvania is a member of both the

DRBC and SRBC. The commissions were

established under federal-state compacts to

manage the water resources of the Delaware

and Susquehanna River Basins and to resolve

interstate conflicts related to water resources.

The federal-state compacts vested these com-
missions with regulatory powers over the

waters of the basins. DEP enforces and implements regulations of the DRBC and SRBC in

eastern Pennsylvania. Because Pennsylvania

lacks regulations for the allocation of ground

water, DRBC and SRBC have basin-wide

comprehensive plans and have the lead role in

setting policies for water allocations within

Pennsylvania for their respective basins.

The DRBC and SRBC have review and

approval authority for ground-water and surface-water withdrawals and consumptive uses.

Withdrawal or consumptive-use capacity that

was in place and operative when each commission was formed (DRBC, October 1961;

SRBC, December 1970) remains unregulated.

Increases in or new withdrawals that exceed

100,000 gpd require approvals. Increases in or

new consumptive uses that exceed 10,000 gpd

also require approvals. SRBC imposes fees for

consumptive uses. Those fees are used to pay

for storage that provides for releases to make

up for consumptive- use losses in the basin

during low-flow events. In a five-county area

in southeastern Pennsylvania where groundwater withdrawals threaten to exceed recharge

rates, the DRBC imposes fees for withdrawals

and ten-fold fees for depletive withdrawals

from basin surface waters. Those fees are used

to pay for storage releases to meet a flow

objective of 3,000 ft3

/s (cubic feet per second)

in the Delaware River at Trenton, N.J.

WATER-USE PROGRAM

Every 5 years since 1950, the U.S. Geological Survey (USGS) has issued reports summarizing water use in the United States. In 1977,

the Congress of the United States recognized

the need for nationally uniform data on water

use and directed the USGS to establish a

National Water-Use Information Program. The

USGS cooperates with state and local agencies

to collect, store, aggregate, and disseminate

water-use information. Through this ongoing

effort, the National Water-Use Information

Program produced a circular “Estimated Use

of Water in the United States in 1995.” The

USGS Pennsylvania District’s Water-Use Program, in cooperation with DEP, compiles

water-use data by county and watershed for

the circulars. The water-use data are based on

the information reported by public suppliers

and collected through water-use surveys by

DEP.

Data on water use are collected by DEP to

support and implement water-management

decisions in the Commonwealth, such as

ensuring water is available to every community, imposing drought controls when necessary, and responding to hazardous-material

spill emergencies. Public suppliers and electric

power generation facilities (and registered

industrial and commercial facilities in the Delaware River Basin) submit annual reports of

water use to DEP. DEP also distributes wateruse surveys to industrial, commercial, and

mining facilities throughout Pennsylvania on a

cyclical schedule. The respondents are asked

to identify sources of withdrawal, withdrawal

amounts, use, consumptive use, discharges,

and recycling. Estimates of water use in Pennsylvania for 1995 are based on data collected

and available at the time of compilation.

—Russell A. Ludlow and William A. Gast

SELECTED REFERENCES

Carr, J.E., Chase, E.B., Paulson, R.W., and Moody, D.W., comps., 1990,

National water summary 1987 - Hydrologic events and water supply and

use: U.S. Geological Survey Water-Supply Paper 2350, 553 p.

Pennsylvania Department of Agriculture, 1996, 1995-1996 statistical summary

and Pennsylvania Department of Agriculture annual report, PASS-119,

95 p.

Pennsylvania Department of Environmental Protection, Water Use Data System

(WUDS), 1996 and 1997 [digital data].

Pennsylvania Department of Environmental Resources, 1975, The State Water

Plan: Planning Principles, SWP-1, 90 p.

Solley, W.B., Pierce, R.R., and Perlman, H.A., 1998, Estimated use of water in

the United States in 1995: U.S. Geological Survey, Circular 1200, 71 p.

U.S. Bureau of the Census, 1994a, Farm and ranch irrigation survey, 1992

census of agriculture, v. 3, part 1: Related surveys, AC92-RS-1, 142 p.

_____1994b, United States summary and state data, 1992 census of agriculture,

v. 1, part 38: Geographic area series, Pennsylvania state and county data

AC92-A-38, 530 p.

U.S. Geological Survey, 1999, National handbook of recommended methods for

water data acquisition—Chapter 11—Water use [online]: January 1999

[cited April 5, 1999], available from World Wide Web

http://water.usgs.gov/public/pubs/chapter11

U.S. Geological Survey, WRD, Pennsylvania District, Aggregated Water-Use

Data System (AWUDS), part of the USGS National Water Information

System (NWIS) [digital data on disk].

Internet Resources

Delaware River Basin Commission

http://www.state.nj.us/drbc/

Pennsylvania Department of Environmental Protection, Office of

Water Management Page:

http://www.dep.state.pa.us/dep/deputate/watermgt/watermgt.htm

Susquehanna River Basin Commission

http://www.srbc.net

US Department of Commerce, Bureau of the Census:

http://venus.census.gov/cdrom/lookup

USGS National Water-Use Information Home Page

http://water.usgs.gov/watuse

USGS Pennsylvania District Home Page:

http://pa.water.usgs.gov

USGS Water Resources Home Page:

http://water.usgs.gov

Water-use data also are published as an

integral part of USGS ground-water,

surface-water and water-quality project

reports and in specialized water-use

project reports. Data on water use are

provided on request to a diverse

audience of public agencies, organizations, researchers, students, and the

general public. The USGS cooperates

with other government agencies, commissions, and non-profit organizations in

water-use projects.