Pennsylvania; A Guide to Private Water Systems: A Manual for Rural Homeowners: On the Proper Construction and Maintenance of Private Wells, Springs, And Cisterns - Penn State University

8/3/2019 Pennsylvania; A Guide to Private Water Systems: A Manual for Rural Homeowners: On the Proper Construction and Maintenance of Private Wells, Springs, And

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A Guide to PrivateWater Systems inPennsylvania

A Manual for Rural Homeownerson the Proper Construction and

Maintenance of Private Wells,Springs, and Cisterns

College of AgriCulturAl SCienCeS


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Ppad by Spha S. Cms, cda, Mas Wow nwk, uvsy Mayad; Bya Swsck, wascs xs spcas, P Sa; ad Wam e.Shap, pss ms, P Sa

This publication was supported by unds provided in part bythe Pennsylvania Department o Environmental Protection, thePennsylvania Ground Water Association, and the CooperativeState Research, Education, and Extension Service Mid-AtlanticWater Program. The opinions and recommendations expressedin this publication do not necessarily reect those o the undingorganizations.

Ackwdms

Many individuals and agencies deserve credit or the creation

o this publication. Among those are each o the undingorganizations, which gave us the opportunity to create adocument ocused solely on assisting homeowners who relyon private water systems. The Pennsylvania Department oEnvironmental Protection, the Pennsylvania Ground WaterAssociation, the Cooperative State Research, Education, andExtension Service Mid-Atlantic Water Program, and the NationalGround Water Association have all demonstrated signifcantsupport o the Pennsylvania Master Well Owner Network(MWON). This publication would not be possible without theirhelp. We would also like to acknowledge Susan Boser, JamesClark, Tom McCarty, Gary Micsky, Dana Rizzo, Peter Wulhorst,Melanie Barkley, Ann Wol, Lisa Carper, and Marie Gildow or

their assistance in compiling inormation used in this publication.

In addition, we thank the ollowing reviewers:

Joseph Lee, Pennsylvania Department o EnvironmentalProtection

G. Patrick Bowling, Pennsylvania Department o EnvironmentalProtection

Thomas McCarty, Cumberland County Cooperative Extension

Todd Reichart, Pennsylvania Ground Water Association, andWilliam Reichart Well Drilling

Mark Ralston, Converse Consultants, Inc.

Last, but certainly not least, we acknowledge the eorts o theMWON Volunteers. Without their contributions to the MWONprogram, much o the research and outreach related to thisguidebook would not have been possible.

Cb Ahs

James ClarkGlossary

Stephanie ClemensSpring Development and Protection, TestingYour Drinking Water, Tips or Buying Water Treatment Equipment,Coliorm Bacteria, and Shock Chlorination o Wells and Springs.

Paul RobillardHome Water Treatment in Perspective,Nitrates in Drinking Water, Corrosive Water Problems, Ironand Manganese in Private Water Systems, Hydrogen Sulfdein Pennsylvania Ground Water Wells, Removal o Arsenic romWells in Pennsylvania, Reducing Radon in Drinking Water,Removing Giardia Cysts rom Drinking Water, Water Sotening,Magnetic Water Treatment Devices

William SharpeProtecting Wells with Sanitary Well Capsand Grouting, Spring Development and Protection, Rainwater

Cisterns, Water Tests: What Do the Numbers Mean?, Home WaterTreatment in Perspective, Coliorm Bacteria, Nitrates in DrinkingWater, Corrosive Water Problems, Lead in Drinking Water, Ironand Manganese in Private Water Systems, Hydrogen Sulfde inPennsylvania Groundwater Wells, Removal o Arsenic rom Wellsin Pennsylvania, Reducing Radon in Drinking Water, Methane Gasand Its Removal rom Wells in Pennsylvania, Removing GiardiaCysts rom Drinking Water, Shock Chlorination o Wells andSprings, Water Sotening, Magnetic Water Treatment Devices

Bryan SwistockA Quick Guide to Groundwater in Pennsylvania,Protecting Wells with Sanitary Well Caps and Grouting, SpringDevelopment and Protection, Water Tests; What Do the NumbersMean?, Testing Your Drinking Water, Home Water Treatmentin Perspective, Coliorm Bacteria, Nitrates in Drinking Water,Corrosive Water Problems, Lead in Drinking Water, Iron and

Manganese in Private Water Systems, Hydrogen Sulfde inPennsylvania Groundwater Wells, Removal o Arsenic rom Wellsin Pennsylvania, Reducing Radon in Drinking Water, Methane Gasand Its Removal rom Wells in Pennsylvania, Removing GiardiaCysts rom Drinking Water, Shock Chlorination o Wells andSprings, Water Sotening, Magnetic Water Treatment Devices,Roadside Dumps and Water Quality

Edward YoungRainwater Cisterns

National Ground Water AssociationWell-DecommissioningProcedures

James GartheRoadside Dumps and Water Quality

Albert JarrettPreventing On-Lot Sewage System Malunctions,Septic Tank Pumping, On-Lot Sewage Systems


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Ctts

Itructi 3

Captr 1Gruwatr 5

The Hydrologic Cycle 5Groundwater Basics 6Threats to Groundwater 8

Captr 2Priat Watr Ssts 9

Water System Planning: Estimating Water Needs 9Proper Construction and Management o Private Water Wells Spring Development and Protection 17Rainwater Cisterns 21

Captr 3Wlla Prtcti a La-Us

Ipacts 30

What Can You Do to Protect Groundwater? 31Unused Wells 31Septic System Malunction or Failure 31Gas Well Drilling 32Roadside Dumps 34 Agriculture Mining 34

Captr 4Watr Tstig a Itrprtati 35

Water-Testing Basics Components o a Typical Water Test Report 37 What Are Drinking Water Standards? 40Description o Common Pollutants (by Category) 41

Captr 5Slig Watr-Qualit Prbls 49

What Options Are Available? Home Water Treatment in Perspective 49Misconceptions About Home Water Treatment 50Common Water Treatment Methods 52

Captr 6Watr-Quatit Issus 64

Water, Water, Everywhere? Water Use in Pennsylvania Outdoor Water Use 65Managing Your Well During a Drought 65Dealing with a Low-Yielding Well 67 Water Conservation or the Homeowner 70

Appi ARlat Wb Sits a Ctact

Irati 74

Appi BGlssar C Trs a

Abbriatis

Appi CIprtat Irati a Rrcs 78


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3

Itructi

Over three million rural residents oPennsylvania rely on a private water system

(individual well, spring, or cistern) or their

home water supply. These water supplies generally

provide adequate and sae drinking water or rural

homes that lie outside the area served by public water

supplies. In addition, surveys o homeowners with

private water systems have ound that more than 80

percent are satised with their water supply.

Despite this general satisaction, rural

homeowners oten ace challenges in managing theirwater supply. Thats because, unlike public water

supplies, managing private water systems is entirely

the homeowners responsibility. Some homeowners

who grew up in rural areas are accustomed to

private water systems, but the increased migration

o city dwellers into rural areas has meant that

many homeowners are unamiliar with the basic

management o these water supplies.

Homeowners may be unaware o the

proper design, construction, testing, and treatmentthat are oten necessary to ensure sae drinking water

rom these supplies. As a result, many problems

go unnoticed. One recent study o 700 private well

owners ound that ewer than 20 percent were aware

o the water-quality problems that existed in their

drinking water.

This manual is intended as a guide or

private water system owners in Pennsylvania. From

proper location and construction to recommended

testing and treatment strategies, it will help youmake educated decisions about your water supply.

Beore ollowing any o the suggestions made in

this publication, check with your local, county, and

state government to make certain that any existing

regulations are met.


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5

Captr 1Gruwatr

The hydRoLoGIC CyCLeAny discussion o groundwater must start with an un-derstanding o the hydrologic cycle, the movement owater in the environment. As the word cycle implies,there is no beginning or end to the hydrologic cycle; itis merely the continuous movement o water betweenplaces.

Lets start with precipitation. Rain is the dominantorm o precipitation across Pennsylvania, accountingor more than 75 percent o the total annual precipita-tion on average. Snow is the other major orm, whichgenerally accounts or less than 10 percent o the annu-al precipitation in southern Pennsylvania and up to 25

percent o the annual precipitation in some northerncounties. The amount o precipitation is surprisinglyvariable across the state, ranging rom just 32 inches inTioga County to more than 48 inches along the Allegh-eny Front and the Poconos. On average, the state re-ceives approximately 40 inches o annual precipitation(rain and melted snow) as a whole.

Where does all this precipitation come rom? Allprecipitation originates rom water evaporated some-where on the Earths surace. Some o the rainall inPennsylvania comes rom water that evaporated romtropical parts o the oceans. Near the equator, thesun provides enough energy throughout the year to

evaporate huge quantities o water that all as precipita-tion all over the world. However, precipitation duringisolated thunderstorms or lake-eect snow squalls mayoriginate rom evaporation much closer to home.

The sun powers the hydrologic cycle, evaporat-ing water rom all over the Earths surace, includingwater in oceans, lakes, elds, lawns, rootops, anddriveways (Figure 1.1). Plants also use the suns energyto evaporate water by taking it rom the soil, using itto grow, and releasing it into the atmosphere throughtheir leaves in a process called transpiration. Evapora-tion and transpiration are commonly combined and

reerred to as evapotranspiration (ET). Nearly all theprecipitation that alls during the growing season inPennsylvania is returned to the atmosphere throughET. During the winter months, however, very little EToccurs because plants do not use much water and thesun is too low in the sky to cause much evaporation.Over the entire year, about 50 percent o the precipita-tion that alls across the Commonwealth returns to theatmosphere through ET.

What happens to precipitation that reaches theearth and is not evaporated or transpired by plants?About 7 inches o Pennsylvanias annual precipitationenters streams directly as runo, either as overlandfow, which travels over the land surace, or as inter-fow, which moves toward streams through soil. Theremainder o the precipitation, about 13 inches, is inthe orm o rechargeprecipitation that inltratesthe soil surace, trickles downward by gravity, and

becomes the groundwater that eeds the springs,streams, and wells o Pennsylvania. Most o this re-charge occurs rom rain and melting snow duringearly spring and late all when the soil is not rozenand plants are not actively growing. Adequate precipi-tation and snowmelt during these short time periodsis critical or supplying groundwater. All groundwaterwas once surace water, and it will be again becausegroundwater is an integral part o the hydrologiccycle. This is natures way o recycling water.

Figure 1.1. The hydrologic cycle or an average year inPennsylvania.

Precipitation =

41 inches

Evapo-

transpiration =

21 inches

Runo =

7 inches

Recharge =

13 inches

Groundwater

discharge =

13 inches

Stream

ow = 20

inches


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may have a watershed o only a ew acres, while ma-jor rivers have watersheds that encompass millionso acres. No matter where you stand, you are locatedwithin one small watershed that is part o many otherlarger watersheds. The largest rivers orming the ma-jor watersheds o Pennsylvania all fow toward one othe oceans.

The average Pennsylvania stream gets about

two-thirds o its fow rom groundwater. Except or ashort time during and ater rainstorms and snowmelt,streams carry water provided only by groundwater thatseeps through stream banks and streambeds into thechannel (this is called basefow). The groundwaterthat orms a streams basefow during dry weatheroten takes a year or more to make the journey under-ground to the streambed. In some groundwater fow

paths, it may take thousands o years or an individualwater molecule to travel to the stream ater it reachesthe land surace as precipitation.

The situation is sometimes reversedstreams maylose some o their fow to groundwater. This happenswhen the water table lies below a stream and doesnot intersect it. In some cases, dierent sections ostreams behave dierently, with some portions gain-

ing groundwater and other losing it. In general, asstreams become larger as they near the ocean, theycontain increasing amounts o groundwater.

Groundwater aquiers vary in size and composi-tion, and the amount and quality o groundwateryielded is also dierent rom aquier to aquier. Thereare our major types o groundwater aquiers in Penn-sylvania (Figure 1.3).

Depth (t) Yield (gal/min)

Aquier type and description

Common

range

May

exceed

Common

range

May

exceed Typical water quality

Unconsolidated sand and gravel

aquiers: sand, gravel, clay, and silt 20200 250 1001,000 2,300Sot water with less than 200 mg/l dissolved solids;

some high iron concentrations

Sandstone and shale aquiers: racturedsandstone and shale 80200 400 560 600

Sandstone layers have sot water with less than200 mg/l dissolved solids; shale layers have hard

water and 200250 mg/l dissolved solids

Carbonate rock aquiers: ractured

limestone and dolomite 100250 500 5500 3,000Very hard water with more than 250 mg/l dissolved

solids

Crystalline rock aquiers: ractured

schist and gneiss 75150 525 220

Sot water containing less than 200 mg/l dissolved

solids; some moderately hard water with high iron

concentrations

Note: t = eet; mg/l = milligrams per liter; gal/min = gallons per minute From Pennsylvania Geological Survey, 1999

Figure 1.3. The our major types o groundwater aquiers in Pennsylvania.


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An Important Resource

Groundwater in Pennsylvania is a vast resource andis estimated to be more than twice as abundant asthe amount o water that fows annually in the statesstreams. Pennsylvanians have tapped into this impor-tant resource. Each day more than one billion gallonso groundwater are pumped rom aquiers through-out the state or various uses. More than hal o this

groundwater is used or domestic drinking-water sup-plies, which demand high-quality, uncontaminatedwater. Although smaller amounts o groundwater areused or agricultural and mining purposes, groundwa-ter still accounts or the majority o all the water usedor these activities (Figure 1.4).

Groundwater is especially vital to rural areas othe state. Second only to Michigan or the largestnumber o private water wells, Pennsylvania has morethan one million private water wells, supplying waterto more than three million rural residents (Figure1.5). An additional 20,000 new private wells are drilledeach year around the state.

Although more groundwater wells are drilledeach year, the total groundwater usage across thestate has remained relatively stable over the past ewdecades. Water conservation measures and educationhave played an important role in keeping groundwa-ter use constant. From 1985 to 1995, Pennsylvaniaspopulation increased by nearly 300,000, but averagewater use ell rom 66 to 62 gallons per person perday. Water conservation measures, such as low-fushtoilets, ront-loading washing machines, low-fowshowerheads, and outdoor rain barrels, can reducehousehold water use by 30 percent. Reduced outdoorwater use is especially important because it saves waterthat largely evaporates (consumptive water use) as op-posed to water that is simply used and put back intothe ground (nonconsumptive water use).

In addition to water savings, water conservationcan also reduce yearly home energy costs by severalhundred dollars in every home. Thus, conservingwater means conserving energy. More inormation onwater conservation can be ound in Chapter 6.

ThReATS To GRoUndWATeR

People rom many parts o Pennsylvania are con-cerned about the uture availability o adequate

groundwater or meeting home and business needs.In some cases, these concerns are due to increasinglocal use o groundwater that exceeds the amount orecharge supplying the aquier. More oten, ground-water supplies are threatened by expanding impervi-ous coverage o the land surace. Each year, more landarea is being covered by roos, sidewalks, driveways,parking lots, and other suraces that do not allowrainwater to recharge the underlying groundwater

aquiers. Every acre o land that is covered with animpervious surace generates 27,000 gallons o sur-ace runo instead o groundwater recharge duringa one-inch rainstorm. Without recharge water eed-ing the aquier, groundwater miningwater beingremoved rom the aquier more quickly than it can berechargedmay occur.

Groundwater mining has been documented inparts o southeastern Pennsylvania, where imperviouscover has increased rapidly and groundwater with-drawals have also increased. Water-resource planningeorts initiated in Pennsylvania in 2003 aim to docu-ment areas where groundwater resources are current-ly overused or may be overused in the uture. Withthis inormation, local government planning ocialscan more adequately guide uture development basedon existing water resources.

Figure 1.4. Groundwater use in Pennsylvania.

Agriculture = 5%

Industry = 19%

Mining = 20%

Water supply = 56%

Figure 1.5. Private water wells reportedly drilled

between 1963 and 1994 to serve individual homes in

Pennsylvania. Each dot represents one drilled well.

Data from the Pennsylvania Groundwater Information System

compiled by the Pennsylvania Geological Survey.


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the water used in the home occurs over very shorttime periods, usually in the morning and evening. Asa result, or planning purposes it is recommendedthat a water system be able to supply all o the daysprojected water use in a 2-hour peak demand period.I you estimate that your home water use will be 400gallons per day, the water system should be sized toprovide this much water in a 2-hour period.

The amount o water that can be delivered romyour well or spring in a given period o time is re-erred to as the well or spring yield. The yield roma spring can be easily measured by determining howmany gallons o water fow rom the outlet pipe everyminute. This fow rate will likely vary considerablywith weather conditions, but, or planning purposes,it would be best to measure fow during a dry time pe-riod. For a well, the yield is considered the maximumrate in gallons per minute (gpm) that a well can bepumped without lowering the water level in the bore-hole below the pump intake.

For most single-amily homes, a minimum fow

o 6 gpm is suggested rom a well or spring. This fowwould provide 360 gallons o water each hour, whichwould be sucient to meet most home water peak de-mands. Higher fow rates may be necessary or largerhomes with more xtures, appliances, and residentsthat may all be using water at the same time. The val-ues in the table below give the suggested minimumfow rates or various numbers o bedrooms and bath-rooms in a home.

Ideally, the yield rom the well or spring will ex-ceed the recommended minimum fow rates in Table2.2. I not, you may need to rely on water storage tomeet peak demand periods. For a drilled well, the

borehole can provide a signicant amount o waterstorage. A typical 6-inch-diameter well stores about1.5 gallons o water or every oot o standing waterin the borehole, and a 10-inch well stores about 4 gal-lons o water per oot. Thereore, a 6-inch-diameterwell with about 100 eet o standing water in the bore-hole would contain about 150 gallons o stored water.However, in some geologic settings, using a signicantamount o the borehole storage (i.e., signicant draw-down or each pumping cycle) may tend to dislodgeparticles rom the borehole and may result in theneed to lter the water.

In the case o a spring, a large spring box can beconstructed where the spring emerges, or a water stor-age tank can be added ater the spring box to provideextra water storage to meet peak demand. The waterstored in the borehole, spring box, or storage tankis helpul when water use in the home exceeds theamount o water fowing rom the well or spring.

Well storage and spring fow can vary dramaticallywith the natural groundwater level, with the highestlevels typically occurring in spring and the lowest lev-els in all. These natural variations can be accentuatedby drought conditions. So, while water storage canallow or the use o wells and springs with lower fowrates than shown in Table 2.2, it may not be reliableduring severe droughts. An approximate estimate o

the amount o water needed beore a well or springis developed can allow the proessional contractor touse the combination o local knowledge, yield, andstorage to meet water demand. For wells that yieldextremely low amounts o water, an intermediate stor-age system can be added (see Low-Yielding Wells inChapter 6).

Estimating Farm Water-Use Needs

Planning or water supply needs is generally muchmore important or arms because much largeramounts o water are oten needed, especially or dairyoperations or arms with large acreages in irrigation.

Midwest Plan Service guidelines suggest that arms us-ing 2,000 gallons per day (gpd) will need a water sourcefow rate o 16 gpm, those using 6,000 gpd will need36 gpm, and those using 10,000 gpd will need 48 gpm.Planning or larger operations starts with an estimate ototal daily water use rom Table 2.3.

Using the estimates rom Table 2.3, current anduture daily water demands on the arm can be es-timated. The arm water system would need to bedesigned to include sustained yield and storage romone or more wells or springs. Where large quantitieso water are needed rom a well, it may be worthwhileto hire a proessional hydrogeologist to locate a high-

yield well using racture trace mapping or other tech-nique or locating a productive well.

It should also be noted that arms using morethan 10,000 gpd must report their annual water use tothe Pennsylvania Department o Environmental Pro-tection as required by the Water Resources PlanningAct.

Table 2.2. Minimum fow rates (GPM) or homes based

on number o bedrooms and bathrooms.

Number o

bedrooms inhome

Number o bathrooms in home

1 1.5 2 3

2 6 GPM 8 GPM 10 GPM


4 10 GPM 12 GPM 14 GPM 16 GPM


6 16 GPM 18 GPM

From Private Water Systems Handbook. 1002. Midwest Plan Service.MWPS-14.


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The required water source fow rate does notnecessarily need to equal the yield rom the well orspring. I water availability is projected to be insu-cient or the calculated peak water demand, addition-al sources must be developed or additional storagemust be used (see Low-Yielding Wells in Chapter 6).

PRoPeR ConSTRUCTIon And

mAnAGemenT of PRIvATe WATeR WeLLS

Beore You Drill a Well

When the decision is nally made to try using ground-water as a water supply or domestic use, livestock, andarmstead demands or irrigation, it is important thatcertain procedures be ollowed to ensure a clean, reli-able, productive well. These important steps includesiting, drilling, and pump testing the well. Althoughollowing the recommendations in this publicationwill not guarantee all the clean water you may need ordesire to have, it will greatly increase your chances o

having a clean, reliable, productive well that is able tomeet your needs.

Finding a Qualied Driller

In most states, regulations were created to ensure thatprivate water wells are constructed properly. In a ewstates, however, no private water well regulations exist.In this case, a well can be drilled using any materials,and the driller does not have to ollow designatedguidelines. In states without regulations, it is pos-sible or well drillers to lack qualications or training.Thereore, it is very important that you take the timeto nd a qualied well driller to make certain that the

system is constructed properly. Find out i the driller isassociated with any organizations such as a state asso-ciation o well drillers or the National Ground WaterAssociation. Usually well drillers with memberships inthese organizations are more educated about properwell construction.

Also, talk to each well driller about the construc-tion o your well. Tell the well drillers that you areinterested in the process and see i they will take thetime to explain what they are going to do. Find a qual-ied well driller at www.wellowner.org.

Beore work starts, make sure to get a written con-tract that gives you a breakdown in cost and materials,provides liability insurance or the driller, and pro-vides a guarantee o workmanship, etc.

Table 2.3. Estimated daily water use in gallons or

various arm animals, equipment, processes, and

irrigation in Pennsylvania.

Animal water use

Milking cows 35 gallons per animal per day

Sprinkler cooling or animals 20

Dry cow, bee cattle, or steers 12

Calves

1-month-old

2-month-old 2.0

3-month-old

4-month-old 3.5

5 to 14 months old

1.5

2.0

2.5

3.5

4.5

Heiers

15 to 18 months old

18 to 24 months old

7.0

Swine 1.5

Horses or ponies 12Sheep or goats 2

Chickens (per 100) 9

Turkeys (per 100) 15

Milkhouse and parlor water use

Automatic bulk tank 50 to 60 gallons per wash

Manual bulk tank 30 to 40 gallons per wash

Pipelines 70 to 120 gallons per wash

Pail milkers 30 to 40 gallons per wash

Milking system clean-in-place(parlor)

12 to 20 gallons per unit

Miscellaneous equipment 30 gallons per day

Cow preparation (per milking)

Automatic

Manual

Wash pen

1 to 4.5 gallons per cow

0.25 to 0.5 gallons per cow

3 to 5 gallons per cow

Milkhouse foor 10 to 20 gallons per day

Parlor foor (hose down) 50 to 100 gallons per wash

Parlor foor and cow platorm 500 to 1,000 gallons per wash

Parlor and holding area foor with fushing

Parlor only 20 to 30 gallons per cow

Parlor and holding area 25 to 40 gallons per cow

Holding area only 10 to 20 gallons per cow

Automatic fushing 1,000 to 2,000 gallons per wash

Irrigation

Sprinkler* 4,000 gallons per acre per day

Drip* 1,000 gallons per acre per day

*The amount o water used or irrigation is seasonal and variesgreatly depending on natural water availability rom precipitation.


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The Proper Location

Groundwater exploration is not a hit or miss (or ran-dom) proposition. Excess rainwater percolates intothe soil and rock beneath the earths surace, accumu-lating in zones o saturation called aquiers. A well is ahole drilled into the aquier rom which a small por-tion o the groundwater can be pumped to the suraceor use. It is true that any well penetrating an aquier

will yield water, but the amount o water producedrom a randomly sited well may be very small.Scientic methods have been developed or locat-

ing wells; such methods involve penetrating zones oractured rock buried beneath the soil surace. Wellslocated on a ractured rock zone will produce muchlarger quantities o water than wells drilled into zoneswhere the rock is not ractured. Finding the racturedrock zones, or better yet, nding the intersection otwo ractured rock zones can be a time-consumingand expensive procedure. Only licensed geologistswith training in aerial photo interpretation and hydro-geology are qualied to locate wells by the racture-

trace technique. I a high-producing well is desired,however, the consultants ee or siting the well ismoney well spent.

In addition to the siting considerations discussedabove, which pertain to nding adequate water, wellsshould be located at least 50 eet rom sewers and sep-tic tanks; at least 100 eet rom pastures, on-lot sewagesystem absorption elds, cesspools, and barnyards;and at least 25 eet rom a silo. These distances areor residential wells and should be increased or armwells in proportion to the demand placed on the well.Areas where groundwater comes to within 10 eet othe soil surace should also be avoided.

Drilling the Well

Drilling a well is more than boring a hole into theearth. A nished well consists o a borehole drilledinto the aquier at a diameter large enough to acceptthe well casing (see Figure 2.1), which receives thepump. The decision about how large the pump mustbe to meet your intended demand must, thereore,be made beore drilling starts. The well casing is sizedto meet the expected pumping need. For instance, a6-inch casing will receive pumps that can pump up toapproximately 100 gallons per minute (gpm). I you

desire to pump more than 100 gpm you will need an8-inch casing, which dictates at least a 12-inch bore-hole. Your well driller will actually make these deci-sions, but he must know your needs.

The borehole itsel can be drilled using any oneo several types o drill rigs, including impact, rotary,or various combinations. Ater the borehole has beendrilled into or through the water-bearing aquier, thewell screen may be installed in the producing zone othe unconsolidated aquier, or the well may be com-

pleted as an open borehole i it is drilled into a rockormation. The zones above the producing aquiermust be cased to prevent cave-ins, and the annulus(space) between the borehole and casing must belled with grout to keep surace contaminants romentering the well. Read more about grouting later inthis chapter.

Developing the Well

Developing a well is the process o clearing the well one particles (nes) let by the drilling operation,and fushing these nes out o the borehole and the

rst ew eet o the aquier. Development is accom-plished by washing, air surging, bailing, or any opera-tion that orces water through the development zoneat high velocities. Developing a well is best done bythe well driller right ater the well is drilled. Properlydeveloped wells may yield more water and will prob-ably produce less turbidity (sediment) than poorlydeveloped wells.

Pumping Test

With the well in place, the question remains, Howmuch water can be pumped rom the well on a sus-tained basis? The sustained pumping rate is depen-

dent on the aquiers ability to move water toward thewell under the infuence o gravity while the well isbeing pumped. To determine the sustained pumpingcapacity o a well, a pumping test should be per-ormed on the well. The pumping test may be com-pleted by the contractor as part o the well drillingcontract. The desire or a pumping test must be madeclear to the driller beore drilling begins becausesome drillers are not able to do the pumping test.

Sand and gravel

aquier

Cement grout

Figure 2.1. Well components.

Gravel pack

Screen

Casing


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13

Be sure to use a driller who can complete all drillingwork, including the pump test.

Several types o pumping tests have been devel-oped, but all are designed to establish the long-termequilibrium rate at which water will fow towards andenter the well. The simplest, most straightorwardpumping test is to place a pump in the well, ater thedevelopment phase is complete, and to pump water

rom the well at a constant rate. The pumped watermust be discharged some distance rom the well so itcannot recirculate back into the well during the pumptest.

The pumping rate should be great enough tostress the well, but not so great as to cause the well tobe pumped dry. During the pumping test, the waterlevel in the well must be measured and recorded atregular intervals, starting at the time pumping beginsand continuing until pumping stops. Pumping testdurations or residential purposes are on the order oseveral hours; higher-yielding municipal and agricul-tural wells may have pumping tests that last or 24 to

72 hours or longer.A cone o depression is produced when water is

removed rom the well bore by the pump, causing thewater level in the well to drop. This means the watersurrounding the well is at a higher elevation and thewater in the rock begins to fow into the well bore. Asthis continues, the distance between the original watertable and the water level in the well, or drawdown,increases and orms a cone o depression. At somepoint, the drawdown reaches a point o equilibrium,where the water fows to the well at the same rate asit is being pumped rom the well, and the change indrawdown over time becomes very small or negligible.

The capacity o a well can be estimated by rst de-termining the wells specic capacity. Specic capac-ity (Sc) o a well is the pumping rate (Q) in gallonsper minute (gpm) during the pumping test, dividedby the drawdown (s) (in eet) at equilibrium. In otherwords, the specic capacity is the fow rate per oot odrawdown.

Sc = Q (gpm) / s (t)

Knowing the depth o the well and where thepermanent pump will be placed, you can assume themaximum permissible depth to water in the well to be10 eet above the permanent pump intake location.

The dierence in elevation between the original watertable and the maximum permissible depth to wateris the maximum drawdown, Smax. The maximumsustainable discharge or the well is then the speciccapacity times the maximum drawdown.

Qmax = Sc (Smax)

Keep in mind that this method or estimatingmaximum sustainable discharge may overpredictsustainable discharge i the well is used continuouslyor or more than residential or light agricultural use.Ater the pumping test is completed, you will havegained knowledge about how much water the well canbe expected to produce.

Sanitary Well Caps and GroutingPennsylvania is one o only a ew states that do nothave mandatory statewide construction standards orprivate water wells. (A ew counties and townshipshave passed well construction ordinancescheck withyour local government oce to determine i they arerequired in your area.) As a result, some importantcomponents o a properly constructed drinking waterwell are oten not installed in an eort to reduce thecost o the well to the homeowner. The most impor-tant eatures missing rom most private wells are asanitary well cap and a grout seal. These componentsare required by most states because they help protect

groundwater by sealing the well rom potential sur-ace contamination.

Types o Well Caps

Most existing and new wells in Pennsylvania have astandard well cap similar to the one shown in Figure2.2. Standard well caps usually have bolts around theside that loosely hold the cap onto the top o thecasing. Since these caps are nonsealing, the small air-space between the well cap and the casing can allowor insects, small mammals, or surace water to enterthe well.

Figure 2.2. A standard well cap similar to those ound

on most Pennsylvania wells.


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A sanitary well cap (sometimes reerred to as avermin-proo well cap) looks similar to a standardwell cap but usually has bolts on the top o the wellcap as shown in Figure 2.3. Most sanitary well capsinclude an airtight rubber gasket seal to prevent in-sects, small mammals, or surace water rom enteringthe well and a small, screened vent to allow or airexchange.

What Is a Grout Seal?

Grout is usually neat cement (no aggregate) that is

pumped into the space between the drilled hole andthe casingcalled the annular space(Figure 2.4). Ben-tonite, a clay material that expands when wet, is alsooten used or grouting a well. The grout is pumpedinto the annular space starting rom the bottom o thecasing using a tremie pipe. The grout is added until itappears at the surace o the ground. Since there areno residential well construction standards in Pennsyl-vania, grouting might not necessarily occur duringthe construction o a private well unless it is requiredby local ordinances, requested by the homeowner,or a part o the well contractors standard operatingprocedure.

Can an Existing Well Be Grouted?

In general, it is not possible to grout an existing well.In rare cases, it may be possible to install a smaller di-ameter casing inside the old casing and grout betweenthe casings. Another method used on existing wells isto pour a concrete slab around the existing well cas-ing. However, these concrete slabs oten crack andprovide minimal protection rom surace contamina-

tion. The best protection or an existing well is tomake sure that the ground surace slopes away romthe well casing in all directions to direct surace wateraway rom the wellhead area.

Bacterial Contamination

Sanitary well caps and grout seal are installed pri-marily to prevent surace contamination, especiallybacterial contamination. Bacterial contamination is acommon problem that occurs in about 40 percent othe private water wells in Pennsylvania. Drinking water

is typically tested or total coliorm bacteria, which in-cludes a large number o dierent species o bacteria,some o which can cause illnesses or diseases. For thisreason, all drinking water supplies should be ree ocoliorm bacteria. More inormation about coliormbacteria can be ound in Chapter 4.

Bacterial contamination o groundwater wellscan occur rom both above and below the surace.Pollution o entire groundwater aquiers aectingmany wells may occur rom ailing septic systems oranimal wastes. Similarly, individual wells may be con-taminated rom the surace i contamination sourcesare located near the wellhead. Surace contamination

o individual wells is usually caused by surace wateror shallow soil water fowing down the outside o awell casing through the annular space; it can also becaused by a loose-tting or absent well cap that allowsinsects, animals, or surace water to directly enter thewell. Sanitary well caps and a grout seal can help pre-vent this type o contamination rom occurring.

Figure 2.3. A sanitary well cap installed on a well

casing.

Figure 2.4. Cross-section o a well casing showing the

grout used to seal the annual space around the casing.

Well capGround surace

Grout

Bottom o casing and

drive shoeAnnular space

Casing

Side o bore hole


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Does a Grout Seal and Sanitary Cap PreventContamination?

A 2002 study by the U.S. Geological Survey o morethan 100 private wells in Pennsylvania examined theimportance o grout in preventing bacterial contami-nation. This study ound that ungrouted wells werethree times more likely to be contaminated withE. colibacteria compared to grouted wells. This same study,

however, ound that coliorm bacteria were still quitecommon in grouted wells. Since the wells used in thisstudy did not have sanitary well caps, the authors theo-rized that coliorm bacteria were entering the wellrom the well cap area. This was supported by their vi-sual assessment that ound nearly 50 percent had obvi-ous insect inestations under the well cap. Insects wereound inside the well cap, on the wiring or plumbing,or inside the casing. Another study by the WisconsinDepartment o Natural Resources ound that insectscould be a source o coliorm bacteria in wells.

A recent Penn State study documented the eecto installing a sanitary well cap on existing water wells.

Sixteen private wells containing coliorm bacteriawere disinected with chlorine and tted with a sani-tary well cap. O these wells, 44 percent did not con-tain coliorm bacteria one month later and 19 percentdid not contain bacteria ater one year. The sanitarywell caps were most successul in eliminating bacteriarom wells that previously contained small numbers ocoliorm bacteria (less than 3 colonies per 100 mL owater), compared to those that had more gross con-tamination.

The study also looked at bacterial contaminationin new wells that had been constructed with a sanitarywell cap and a grout seal. Only 29 percent o thesenew wells contained coliorm bacteria, suggesting thatproper well construction practices can reduce but notcompletely eliminate bacterial contamination. Wellsdrilled into aquiers contaminated by animal wastes,septic systems, or surace water can contain coliormbacteria regardless o well construction practices.

What About the Cost?

Sanitary well caps and a grout seal are generally notused on private wells because o the added cost un-less they are required by local ordinance. Sanitarywell caps typically cost $40 to $50 compared to $20 to

$30 or a standard well cap. A sanitary well cap can beinstalled by a homeowner with some basic knowledgeo electrical wiring, or the cap can be installed by awell driller. In the recent Penn State study, the averagecost or disinection and installation o a sanitary wellcap by a well driller was about $100 per well. Groutingo a new well typically adds $500 to $1,000 to the costo the well. The cost o grouting will depend on thewell depth, diameter, and type o bedrock in the area.It is the prerogative o educated consumers to there-

ore determine how best to spend their investmentdollarson proper well construction employing bestpractice methodology or on treatment equipment toaddress water-quality issues that may be related to sub-standard well construction.

What Can You Do?

Contamination related to an inadequate well cap or

missing grout seal will most likely result in the pres-ence o coliorm bacteria in your well water. The rststep in properly managing an existing private well,thereore, is to have an annual test done or total coli-orm bacteria. You can arrange this test through a lo-cal certied laboratory (a list o labs is available onlineat water.cas.psu.edu) or, in Pennsylvania, your region-al Department o Environmental Protection oce.

I your well tests positive or coliorm bacteria, asanitary well cap may help solve the problem, espe-cially i your well contains small numbers o bacteria.Even i your well is currently ree o bacteria, a sani-tary well cap will help ensure that it does not become

contaminated in the uture by insects or other con-taminants around the wellhead. Sanitary well capscan usually be purchased rom a local water wellcontractor. Consult www.wellowner.org to nd a localwater well contractor certied by the National GroundWater Association. The contractor can also be hiredto disinect the well and install the sanitary well cap iyou desire.

I you do the work yoursel, the existing well capshould be removed and any obvious insects, nests, orsmall mammals should be removed rom inside thewell casing. Existing bacteria in the well water can bekilled using a chlorine solution beore installing the

new well cap. (Note: installing the well cap should bedone with caution owing to the involvement o elec-trical wiring.) Inormation about shock chlorinatingyour well can be ound in Chapter 5. I you are havinga new well drilled, you should request that the well begrouted to prevent surace contamination. I you havean existing grouted or ungrouted well, make sure theground surace is sloped away rom the casing in alldirections to direct surace water away rom the well.

Well Maintenance

Ater your well is properly constructed, it is very im-portant to do preventative maintenance on an annualbasis. Each year, a well owner should take the time toinspect the wellhead and the area surrounding it. Thisinspection should ocus on nding cracks or damageto the well casing, checking the well cap to make sureit is in good condition and securely astened, checkingto make sure that water cannot pond around the well-head, and looking or any nearby activities that couldcause contamination to the water supply. You shouldalso test your water each year at least or coliorm bac-


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teria. Include the annual water test report and notesrom your annual inspection in a le that you keepwith other important documents about your home.

Besides the annual preventative maintenance thata homeowner can perorm, it is also benecial to havea well inspection done by a qualied water well drillerat least every ten years. Have these inspections moreoten i you harbor concerns about your well or the

quality o your drinking water. A qualied well drillercan be ound at www.wellowner.org.

Dealing with Unused Wells

Pennsylvania has one o the largest rural populationso any state in the country, and most rural populationsdepend on private water systems or drinking water.Thus it is not uncommon to nd old, unused wellsthroughout the state. Homeowners may choose toabandon a well on their property i it is plagued withproblems and they believe that a new well will providea high-quality water supply. A well may also go unusedi it does not provide an adequate yield and a new well

is thought to provide a more abundant water supply.Regardless o the reason that a well is no longer

in use, it is very important or any unused well to beproperly sealed (or decommissioned) by a qualiedwell driller. The goal o sealing a well properly is torestore the area to the same condition (or better)that existed beore the original well was drilled. Anunused well that is not properly sealed becomes adirect conduit or surace contamination to aect thesurrounding groundwater supply. In certain situationsan unused well that is not sealed properly can lead tomixing between aquiers o poor and good water qual-ity. Besides the potential pollution that an unused

well might cause, it can also be a physical hazard andsealing it properly will help to prevent injury. It is neveracceptable or unused wells to be used or the disposal o anytype o liquid or solid waste.

Well-decommissioning Procedures

Many states have regulations detailing the proceduresthat should be used to properly seal an unused well.Pennsylvania currently has no statewide residentialregulations regarding this process. The proceduresoutlined below are based on the recommendations othe National Ground Water Association. (Note: Penn-sylvania has regulations and guidelines or properlydecommissioning all public water supplies; guidelinesor private water supplies can be ound in the Ground-water Monitoring Guidance Manual, available rom yourlocal oce o the Pennsylvania Department o Envi-ronmental Protection or on its Web site at www.dep.state.pa.us.)

The goal o sealing an abandoned well properlymay vary depending on the wells construction, geo-logical ormations encountered, subsurace water

chemistry, and prevailing hydrologic conditions. Thebasic concept governing proper sealing o abandonedwells is the restoration, as ar as easible, o the hydro-geologic conditions that existed beore the boreholewas drilled and the well constructed. This serves thepurposes o removing the abandoned well as a con-duit or loss o hydrologic pressure in conned orma-tions, intermingling o groundwaters o diering qual-

ity, and entry o contaminated and polluted water.The purpose o sealing an abandoned waterwell properly is to accomplish several objectives: (1)elimination o a physical hazard; (2) prevention ogroundwater contamination; (3) conservation o yieldand maintenance o hydrostatic head o aquiers; and(4) prevention o the intermingling o desirable andundesirable waters.

To seal an unusable or abandoned well or bore-hole properly, the hydrologic character o the ground-water encountered by the well must be considered.I the well was drilled into an unconned aquier(also reerred to as a water table aquier), the primary

concern is to prevent surace water rom entering thehole and contaminating the groundwater supply. Ithe unused well was drilled into a conned aquierwith artesian conditions, then the sealing proceduremust be done so that water is restricted to its originalaquier and there is no loss o artesian head pressure.This will ensure that there is no contamination o sur-rounding aquiers or loss o artesian head pressure.

The rst step in properly decommissioning aprivate water well is to hire a qualied proessional.Use special consideration i the well to be plugged isa fowing artesian well. In this situation, you shouldselect a driller who has extensive experience in sealing

an artesian well. You can locate a well driller in yourarea at the Web site, www.wellowner.org. Ater a quali-ed driller is obtained, the ollowing steps should betaken:

1. Research must be done on the well. Any recordson the well, including the well log or mainte-nance records, should be ound and given to thecontractor. I no records can be obtained, then adown-hole camera and other techniques can beused to enable the contractor to gather inorma-tion about the borehole.

2. It is strongly suggested that any material poten-

tially hindering the proper sealing o a decom-missioned well should be removed. In most situa-tions, the well casing or liner should be removedrom the borehole along with the pitless adapter,pump, screen, and any debris that has allen intowell. I the contractor nds that the casing can-not be removed, then it should be perorated ordestroyed to the point that the pressurized groutully comes into contact with the borehole walls


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and properly seals the hole. I conrmed anddocumented evidence can be obtained that theannular space between the casing and boreholewas indeed sealed and properly grouted duringthe wells installation and that these procedureswere carried out in accordance with applicablestate regulations and/or industry standards inabsence o governing regulations, this segment o

the operation can be bypassed with the agreemento all interested parties.

3. The well should be shock chlorinated (100 to 500mg/L) to reduce the presence o bacteria andthe chance that the sealed well might be a uturesource o bacteria or other wells in the area. Inthe event that chlorine concentrations greaterthan 100 mg/L are to be used, the contractorshould consider the sealing material and methodsto be used and the possible impact o elevatedchlorine levels on the long-term sealing capacityo the sealing medium and method selected.

4. A grout or cement material chosen by the con-tractor should be used to seal the hole. Thematerial will not plug the hole properly i it isdumped rom the surace, since grout particleswill separate as they all through water. The seal-ing material must be introduced at the bottom othe borehole and lled up to the surace usinga tremie or grout pipe, cement bucket, or dumpbailer under pressure. Any borehole or well thatis to be permanently sealed should be completelylled in such a manner that vertical movement owater within the well bore, including along the an-nular space surrounding the well casing, is eec-

tively and permanently prevented. Methods andequipment used or the sealing should be selectedbased on recommendations rom a qualied pro-essional.

5. Inormation about the decommissioned wellshould be recorded and a copy o the report givento both the homeowner and the state or localregulatory agency.

More inormation about the National GroundWater Association and its specic recommendationsor well decommissioning can be ound atwww.wellowner.org.

SPRInG deveLoPmenT And PRoTeCTIon

Springs occur wherever groundwater fows out romthe earths surace. Springs typically occur along hill-sides, low-lying areas, or at the base o slopes. A springis ormed when the water table intersects the groundsurace due to geologic or topographic actors. Thiscan occur at a distinct point or over a large seepagearea. Springs are sometimes used as water supplies

and can be a reliable and relatively inexpensive sourceo drinking water i they are developed and main-tained properly.

What to Consider

When considering using a spring as your source odrinking water, it is important to ensure that the rateo fow is reliable during all seasons o the year. Springfow that fuctuates greatly throughout the year is anindication that the source is unreliable or may have thepotential or contamination. It may be possible to learnabout historical spring fow rom the previous owner ora neighbor. Water quality is also important to consider

beore using a spring as a water supply. Beore develop-ing the spring, collect a sample o water and have it an-alyzed at a local water-testing laboratory to ensure thatit can be eciently and economically treated to make itsae or human consumption (see Chapter 4 or moreinormation about water-testing options).

Springs may be susceptible to contamination sincethey are oten ed by shallow groundwater, which mayfow through the ground or only a short period otime and may interact with surace water. For this rea-son, most springs will need some treatment beore thewater is considered sae or drinking. Testing helpsto determine exactly how much treatment is neces-sary and may help determine i other sources o waterwould be more economical.

Preparation

Since springs are oten ed by shallow groundwater,water quantity may be an issue during certain timeso the year. I possible, the fow rate or your springshould be monitored or an entire year, but it is mostcritical to measure the fow rate during late summerand all when groundwater levels and spring fows areusually at their lowest. Springs used or drinking watersupplies should yield at least two gallons per minute

throughout the entire year unless water storage is go-ing to be used. The amount o water you will needrom your spring depends entirely on your house-holds daily water needs. Water needs or an individualhome vary depending on water use, water storage, andwater-saving devices within the home. However, theaverage home requires approximately 50 to 75 gallonso water a day per person. More inormation on deter-mining your household water needs can be ound atthe beginning o this chapter.


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The fow rate o a small spring can be tested bydigging a ve-gallon bucket into the outlet channelo the spring and allowing the water to fow into thebucket. Determine the fow rate in gallons per minute(gpm) by timing how long it takes the water to ll thebucket. Example below:

Flow rate = volume/time

= 5 gallons x 60 sec = 8.9 gpm34 sec 1 min

Obtain a sample collection container rom acertied water lab and send a sample o the springwater to the lab or water-quality testing. A list o labsis available at water.cas.psu.edu/ or rom your countyPenn State Cooperative Extension oce. You can startdeveloping your spring once you determine that thequantity and quality are acceptable.

Procedures or Developing the Spring

A spring can be developed into a drinking water sup-ply by collecting the discharged water using tile orpipe and running the water into some type o sanitarystorage tank. Protecting the spring rom surace con-tamination is essential during all phases o spring de-velopment. Springs can be developed in two dierentways; the method you choose will depend on whetherit is a concentrated spring or a seepage spring. Thegeneral procedures or spring development are out-lined in the ollowing pages. Some o these proce-dures are adapted rom the Midwest Planning Servicepublication, Private Water Systems Handbook. This pub-lication (MWPS-14) is available or purchase at www.nraes.org or by calling NRAES at 607-255-7654.

Concentrated Springs

A concentrated spring typically occurs when ground-water emerges rom one dened discharge in theearths surace. Concentrated springs are visible andare oten ound along hillsides where groundwater isorced through openings in ractured bedrock. Thistype o spring is relatively easy to develop (see Figure2.5) and is usually less contaminated than other types

o springs.Steps or developing a concentrated spring are asollows:

Excavatethelandupslopefromthespringdis-charge until water is fowing three eet below theground surace.

Installarockbedtoformaninterceptionreser-voir.

Buildacollectingwallofconcreteorplasticdownslope rom the spring discharge.

Installapipelowinthecollectingwalltodirectthe water rom the interception reservoir to a con-

crete or plastic spring box. (Note: problems withspring fow can occur i water is permitted to backup behind the wall.)

Removepotentialsourcesofcontamination,anddivert surace water away rom the spring box orcollection area.

Alternativetypesofinterceptionreservoirsandcollecting walls can be constructed.

Figure 2.5. Development o a typical concentrated spring.

Spring box

Overow

10 minimum

Diversion ditch

Creviced rock

Gravel

Collecting wall

Lead-in pipe

To storage

Drain


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Seepage Springs

Seepage springs occur when shallow groundwateroozes or seeps rom the ground over a large areaand has no dened discharge point. This type ospring usually occurs when a layer o impervious soilredirects groundwater to the surace. Seepage springscan be dicult to develop (see Figure 2.6). They arealso highly susceptible to contamination rom surace

sources, and they need to be monitored beore devel-opment to ensure that they will provide a dependablesource o water during the entire year. Flow is otenlower rom seepage springs, making them less de-pendable.

Figure 2.6. Spring development in a seep area.

10 minimum

Spring box

Overow

To storage

Drain

Diversion ditch

Water-bearing layer

Impervious layer

Gravel-flled trench

Collecting wall

Lead-in pipe

4 tile collecting system

Gravel-flled trench covered with

plastic sheet and 12 o soil

4 lead-in pipe

Collecting

wall 46 concrete

Spring box

Overow

To storage

Drain

Note: Trench should be 1824 (inches) wide, extend 6 (inches) into (but not through) the impervious layer, and reach 46 (eet) beyond the seep area

on each side.

Cross-section


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Spring Box Considerations

A spring box is a water-tight structure built aroundyour spring to isolate it rom contaminated suraceruno. (See Figure 2.7.) It is critical that this box bebuilt properly to ensure that surace water, insects, orsmall animals cannot enter the structure. I designedproperly, it can provide a small amount o reserve stor-age during a situation when the spring fow rate is be-

low normal. It is important to keep surace water awayrom the spring box, and animals should be encedout o the springs drainage area. All activities shouldbe kept to at least 100 eet rom the spring box.

Digtestholesupslopefromtheseepuntilyoulo-cate the point where the impervious layer is 3 eetunderground.

Createatrenchapproximately18to24incheswide across the slope. The trench should be ex-tended 6 inches into the impervious layer (belowthe water-bearing layer) and should extend 4 to 6eet beyond the seepage area. Install 4 inches o

perorated pipe and surround it with gravel. Installingacollectingwallwillhelppreventwater

rom escaping the collection tile. This collectingwall should be constructed o 4 to 6 inches o con-crete.

Perforatedpipeorcollectiontileshouldbecon-nected to 4-inch pipe that leads to the spring box.The box inlet must be below the elevation o thecollector tile.

Removepotentialsourcesofcontaminationanddivert surace water away rom the spring box andcollection area (Figure 2.8).

Proper Management o Springs

No matter what type o spring you have developed,it is critical that you remove potential sources ocontamination rom the springs drainage area (thearea upslope o the spring discharge point). Makesure to keep water-quality-threatening activities to

at least 100 eet rom a spring box, especially in theupslope position. Surace water draining into thatarea should be redirected and all activities limitedwithin the drainage area. I livestock are present, useencing to keep animals out o the drainage area.

Once the spring is developed and nearby sourceso contamination are eliminated, it is important to dis-inect the entire water system and then submit a watersample to a state-certied water-testing laboratory orwater-quality analysis. I a water test indicates bacte-rial contamination, check the water supply locationand construction o the system or potential pollutionpathways. I improvements can be made, the systemshould then be shock chlorinated. Ater two weeks,have the water retested by a state-certied water-testing laboratory. I the water again tests positive orbacterial contamination, you have the option o nd-ing a new source o water or installing a continuousdisinection system, such as an ultraviolet light. Mostsprings used or drinking water require some type ocontinuous disinection system to make certain thatthe water is sae or consumption. For more inorma-

Figure 2.7. Spring box example.

Figure 2.8. Spring box construction.

4minimum

3 minimum

Overow

Maximum

water

level

Steps

Shuto

valve and

box

To storage

Cleanout

drain

Light-tight,

watertight concrete

cover

6 concrete

Inlet

pipe

Screen

Lock


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RAInWATeR CISTeRnS

Roo-catchment cisterns are systems used to collectand store rainwater or household and other uses.Such systems consist basically o a house roo, orcatchment, and a storage tank or cistern. A system ogutters and downspouts directs the rainwater collectedby the roo to the storage cistern. The cistern, typicallylocated underground, may be constructed o various

materials including cinderblock, reinorced concrete,or precast concrete, berglass, or steel. The cisternsupplies water to the household through a standardpressurized plumbing system. A typical arrangementor a roo-catchment system is shown in Figure 2.9.

Current use o rainwater cisterns may be increas-ing. Those who live in areas where groundwater andsurace water are unobtainable or unsuitable or usehave been compelled to resort to cisterns as sourceso water. Rainwater collection on a household scale isquite practical in areas where there is adequate rain-all and other acceptable sources o water are lacking.The coal strip-mining region o western Pennsylvania

is one such area. Mining has rendered much o the

tion on treating water supplies containing coliormbacteria, consult Chapter 5.

Drinking Water rom Roadside Springs

In Pennsylvania it is not uncommon or rural resi-dents to use roadside springs or drinking water. Itsimportant to understand, however, that roadsidesprings are just as vulnerable to bacterial contamina-

tion as other privately owned springs. In act, manyroadside springs that are located on public propertymay already undergo disinection to ensure that thesource is sae or consumption. Any roadside springthat is being used as a drinking water supply shouldbe tested or total coliorm bacteria. These springsshould only be used as a source o drinking water ithey have been tested and ound to be bacteria ree.When it comes to your amilys health and saety,never assume that a water supply is sae or drinking.Surveys conducted by Penn State researchers haveound that more than 75 percent o untreated springscontain unsae levels o bacteria.

Figure 2.9. Typical roo-catchment cistern system.

Gutter guard

Roo washer

Manhole access

Water haulers fll pipe

1 line to

house pump

below rost

line

4 line

inlet to

cistern

Force breaker

Screened intake

Force

breaker

4 overow


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ground and surace water unt or drinking and otheruses in large portions o these areas. Rural residents,orced to nd other sources o water, have invariablyturned to roo-catchment cisterns.

Roo-catchment cisterns may also be used to sup-ply water to arms. Watering troughs and rain barrelscan be lled by water collected rom barn and otheroutbuilding roos. A storage cistern built alongside a

barn or other building could serve as an emergencysource o water or reghting in the event that apond was not nearby. However, the use o rainwateror supplying domestic water needs is not without itsproblems.

Water-quality is o concern, especially when therainwater is to be used or drinking in addition toother domestic uses. Rainwater and atmosphericdust collected by roo catchments contain certaincontaminants that may pose a health threat to thoseconsuming the water. Lead and other pollutants mayaccumulate in cistern bottom sediments; and untreat-ed rainwater is quite corrosive to plumbing systems.

Measures must be taken to minimize these and otherwater-quality problems in cistern systems. Recommen-dations or doing this are presented below, as well asguidelines or designing and building roo-catchmentcistern systems.

Cistern Design

The storage capacity o a rainwater cistern depends onseveral actors:

theamountofrainfallavailableforuse

theroof-catchmentareaavailableforcollectingthat rainall

thedailywaterrequirementsofthehousehold

availablemoneysupply

All but the rst o these actors can be controlledto some extent by the cistern owner.

Available Rainall

Across most o Pennsylvania, annual rainall averagesaround 40 inches. During drought years there may beas little as 30 inches, while excessively wet years mayproduce 50 or more inches o rainall. For most plan-ning purposes the average gure should be used, al-though designing a cistern based on the lowest gure

would guarantee enough storage to get you througheven the driest years.

Owing to evaporative and roo-washer losses (tobe discussed later), only about two-thirds o the annu-al total rainall is actually available or cistern storage.

Daily Water Needs

The amount o water you design your roo-catchmentcistern to collect and store depends on your daily wa-ter needs. I you have a small catchment area and alow-volume cistern, then your water use will be limitedaccordingly. So it is important when designing a roo-catchment cistern system to have some idea how muchwater you will require rom it every day.

Various estimates o household water use havebeen published. The average base use determinedby water utilities is 7,500 gallons per month, whichis equivalent to an average yearly minimum need o90,000 gallons per household. Common householdplanning provides or 50 to 75 gallons a day per per-son, or 73,000 to 110,000 gallons a year or a amily oour. One-third to one-hal o this amount is used orfushing toilets. However, those who must rely solelyon rainwater-ed supplies will undoubtedly use lesswater.

It should be clear rom this brie discussion owater use that there is considerable variation, depend-

ing on the circumstances. For purposes o generalcistern design, the gure 50 gallons a day per personis probably the best one to use. This gure would beapplicable or a amily living in a home with hot andcold running water and all the modern conveniences(including automatic washer and dishwasher), andno special water conservation measures. The installa-tion o water-saving devices could considerably reducehousehold water use with no conscious eort onthe part o amily members. Additional inormationon water conservation in the home can be ound inChapter 6.

Catchment AreaThe roo area to be used as the collection suraceis usually predetermined by the size o the existinghouse or other outbuilding roos. However, whenplanning a rainwater collection system rom theground up, where the size o the catchment is to bedesigned to suit domestic water needs, the ollowingguidelines will be useul.

Figure 2.10 allows the catchment area requiredto be determined based on annual water needs andannual precipitation. As an example, suppose the av-erage annual precipitation or your area is 40 inches.

You have determined that your amily o our requires200 gallons a day or 73,000 gallons annually. FromFigure 2.10 the needed catchment area is determinedto be 4,400 square eet. (Note: Roo area can be de-termined by measuring the outside o the building orbuildings to be used to collect rainall. Do not mea-sure the actual roo surace unless it is horizontal.)


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Cistern Size

A cistern should have sucient storage capacity tocarry the household through extended periods o lowrainall. A three-month supply o water, or one-ourtho the annual yield o the catchment area, is generallyadequate in areas such as Pennsylvania where the rain-all is distributed airly evenly over the course o theyear. For example, i you have determined your an-

nual domestic water needs to be 40,000 gallons (andmost important, you have enough catchment area andannual precipitation to supply this amount o water),then you should design and build a cistern with a10,000-gallon storage capacity.

A minimum storage capacity o 5,000 gallons isrecommended or domestic cisterns. This capacityshould eliminate having to buy or haul water, a prac-tice that is not only inconvenient but can becomesomewhat costly. Remember these words o wisdomwhen designing your roo-catchment cistern: You payor a large cistern once and a small one orever.

Cistern Construction

Location

Cisterns should be located as close as possible to thehouse or wherever the water is to be used. They maybe built above or below ground, but below-groundcisterns are recommended in this part o the countryto avoid reezing during the winter months. Under-ground cisterns also have the advantage o providing

relatively cool water even during the warmest monthso the year. Cisterns may be incorporated into build-ing structures, such as in basements or under porches.This way you can use oundation walls or structuralsupport as well as or containment o stored rainwater.

A cistern should be located where the surround-ing area can be graded to provide good drainage osurace water away rom the cistern. Avoid placing

cisterns in low areas subject to fooding. Both o theabove steps will reduce the chance o storm runocontaminating the stored cistern water.

Cisterns should always be located upslope romany sewage disposal acilities; at least 10 eet awayrom watertight sewer lines and drains, at least 50 eetaway rom non-watertight sewer lines and drains, sep-tic tanks, sewage absorption elds, vault privies, andanimal stables, and at least 100 eet away rom sewagecesspools and leaching privies. It pays to check thesethings out careully beore turning the rst shovelulo earth or the cistern excavation.

In certain situations, such as a barn or other

outbuilding roo that supplies collected rainwater toa house downslope, cisterns may be located so as toprovide gravity fow to the place o use. This setupis denitely preerable i it can be worked into yourparticular system. In most cases, however, the level owater stored in underground cisterns is lower than thepoints o use within the distribution system, so a pumpand pressurized system are usually required.

Construction

Cisterns can be constructed rom a variety o materi-als, including cast-in-place reinorced concrete, cin-derblock and concrete, brick or stone set with mortar

and plastered with cement on the inside, ready-madesteel tanks, precast concrete tanks, redwood tanks,and berglass. Cast-in-place reinorced concrete isconsidered the best, especially or underground cis-terns. However, cinderblock-walled cisterns with con-crete foors are common and quite satisactory or be-low-ground construction; these are usually somewhatless expensive than the all-concrete version. Concretewalls and foors should be at least 6 inches thick andreinorced with steel rods.

A general plan or a below-ground concretecistern is shown in Figure 2.11. I cinderblock orconcrete block is used or the walls o the cistern, allhollow cores should be lled with concrete and rein-orced rods should be placed vertically to add strengthto the structure. Footers may be necessary or largercisterns. Footing drains should be installed aroundthe perimeter o the cistern and drained to daylight.This reduces the chances o contaminating cisternwater rom the outside and also prevents the possibil-ity o saturated soil providing an excessive horizontalload against the cistern walls.

Figure 2.10. Graph used to determine catchment area

needed.

Totalannualwaterneeds,

thousandsogallons

140

120

100

80

60

40

20

0 1,000 2,000 3,000 4,000 5,000 6,000

50

40

30

Catchment area, square eet

Norm

alannu

alpre

cipitatio

n,inche

s


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The top o the cistern should be reinorced

concrete and should t tightly onto the rest o thestructure. The top may consist o individual panels orit may be a one-piece slab. In any event, a manholethrough the top o the cistern to allow access to thestorage tank should be included. Such an openingshould be at least 2 eet across. A heavy concrete oriron lid should be tted tightly over the opening toprevent the entrance o light, dust, surace water, in-sects, and animals.

Manhole openings should have a watertight curbwith edges projecting several inches above the level othe surrounding surace. The edges o the manholecover should overlap the curb and project downward

a minimum o 2 inches. Manhole covers should beprovided with locks to urther reduce danger o con-tamination and accidents.

Place the manhole opening near a corner or anedge o the structure so that a ladder can be loweredinto the cistern and braced securely against a wall.The access is necessary or the periodic maintenancetasks, to be discussed later. An alternative is to buildconcrete steps and handholds into the cistern wall be-neath the opening.

Figure 2.11. Cross-section o a concrete cistern with lter (not to scale).

GravelStone

3/8 round bars

8 O.C. both ways

6 galv. metal dam

in constr. joint

Screened end

Fill

Original

groundlevel

2 overowVaries

4-0

hdw.

cloth

Inlet pipeVaries

Force breaker

To house pump

Downspout

Flapvalve

2 inlet

5-0

1-10 42

4

6

5

16

44

5 Sand

2 overow

The interior walls and foor o the cistern should

be smooth to make cleaning easier. A cement plastercan be spread over the interior, depending on howrough the basic construction is. Cement-based seal-ants, such as Thoroseal and Sure-Wall, can be appliedto the interior as well, to provide a smoother nishand urther protection against leakage. A cistern thatleaks is useless, but it is dangerous as well; i storedwater can leak out, contaminated surace and ground-water can leak in. It is worth the time when buildinga cistern to do it rightget a good builder who willguarantee his work against leakage.

Vinyl liners may be used to prevent leakage insome cisterns, but they are usually troublesome. They

are expensive and prone to puncture, and they preventthe use o cleanout drains and other accessories insidethe cistern. Try a vinyl liner only as a last resort when allother eorts to prevent leakage have ailed.

Another important eature o a well-designedcistern is an overfow pipe or pipes. The overfow canbe in the orm o a standpipe that leads through thefoor o the cistern to a drain. Such an overfow pipe,or any other cistern outlet or that matter, shouldnever be connected to a sewer line, either directly or

Manhole accessfor cleaning


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A separate input pipe or adding hauled wateris another important eature o the well-designedcistern. Where possible, it is best to locate the above-ground portion o the ll pipe near the driveway orother road surace, so that the water truck does nothave to drive over your lawn to reach it. Four-inchplastic pipe makes a good ll pipe. Place a tight-ttingcap over the above-ground end o the pipe. You may

want to padlock the cap to urther reduce the possibil-ity o contamination.Water entering the cistern with any kind o orce

behind it, as during a summer thundershower, orrom a water truck, tends to agitate the stored waterand possibly stir up sediment unless steps are taken tolower the orce o the incoming water. One way o do-ing this is through the use o orce breakers.

Water entering the cistern rom either the roo ora water truck should travel down a 4-inch plastic pipeinto a orce breaker box made rom concrete blocks.The blocks should be set in mortar on the foor o thecistern with the cavities acing up. Slots or openings

with an area o at least 13 square inches need to becut into the lower end o the pipe to allow the incom-ing water to move rom the pipe to the cistern. Forcebreakers should be installed under both roo-waterand water-hauler inlets.

Roo Washers

Several other very important construction eatureswill help ensure good-quality cistern water. Roo wash-ers and roo-water lters were mentioned earlier, andtheir importance and construction details are dis-cussed here.

A lot o dirt and dust collects on the roo-catch-

ment surace between rainstorms. This debris caninclude particles o lead and other atmospheric pol-lutants as well as bird droppings. These contaminantswill enter the cistern along with the roo water unlesssteps are taken to prevent contamination. The useo roo washers and roo-water lters can reduce theamounts o these contaminants entering the system.

The rst water to come o the roo at the begin-ning o the rainstorm is the most contaminated. Thedegree o contamination will depend on several thingsincluding the length o time since the last rainall,proximity o the catchment to a highway or other lo-cal source o airborne pollution, and the local birdpopulation. Also, certain types o materials are pre-erable or the catchment surace, as will be detailedlater.

A roo washer is a mechanism that diverts thisinitial highly contaminated roo water away rom thecistern. Once the catchment surace has been washedo by an adequate amount o rainall, the roo wateris once again routed to the cistern or storage. Usuallythe rst 0.01 inch o rainall is considered adequate

indirectly. The drain line can also lead to a ree outletdownslope rom the cistern. The diameter o the over-fow pipe should be at least as large as the diameter othe infow pipe rom the roo catchment.

The outside end o an overfow pipe should be e-ectively screened using a ne mesh rust-proo screen-ing to prevent the entrance o animals and insects.The screening can be cut to a size large enough to be

wrapped over the end o the overfow pipe and shouldbe secured with a hose clamp or similar asteningdevice.

Large-diameter plastic pipe should be used orthe overfow pipe in any case. When designing over-fow outlets, its important to provide good drainageaway rom the cistern and house.

A cleanout drain is also a key eature that allowsthe cistern to be drained or periodic cleaning andmaintenance. A cistern without a drain has to bepumped out beore any maintenance or cleaning canbe done.

A cleanout drain should lead to a ree outlet and

never a sewer line. The foor o the cistern should besloped slightly toward the drain or ease o cleaning. Avalve to open and close the drain should be controlledrom above ground level. The valve and drain lineshould be insulated by a sucient depth o earth toprevent reezing during even the most severe winterweather.

The cleanout drain line needs to be at least 3 or 4inches in diameter to avoid clogginga large amounto sediment may have to move through the line dur-ing cleaning operations. The outlet should be locatedwhere draining water will not cause any problems orcomplaints rom neighbors.

Cisterns should be vented to allow resh air tocirculate into the storage compartment. One or morelarge diameter pipes through the top o the cisternwill serve this purpose. The outside opening o eachpipe should be screened in the same manner as thatdescribed above or overfow pipes. The openings,located several eet above the ground level, shouldace the direction o the prevailing winds, west in mostcases, to maximize ventilation. Four or six-inch diam-eter plastic pipe is good or vents. Make sure there is awatertight seal where each vent pipe goes through thetop o the cistern.

The water line rom the cistern to the house orother place o use should be buried below the rostline and should be 1 or 1 inches in diameter. The in-take head should be eectively screened and elevateda minimum o one oot above the foor o the cisternto prevent sediment rom being drawn into the distri-bution system. The portion o the intake pipe withinthe cistern should be plastic. The best position or theintake is on the opposite side o the cistern rom theroo-water input pipe.


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to remove most o the dust and dirt rom the suraceo the catchment. In this way, only the cleanest roowater is collected in the cistern, whereas the contami-nated roo wash is discharged to waste.

There are several ways o accomplishing thisobjective. The roo water can be diverted manuallythrough a series o valves within the spouting system,or automatic roo washers may be abricated by

the cistern owner or purchased rom commercialdistributors.A simple roo-wash diverter is shown in Figure 2.12.

This particular design requires manual operation oa fap valve to control the fow path o the roo waterwithin the spouting system. Such a valve would be nec-essary on each downspout unless they all convergedinto a single pipe just beore emptying into the cistern.The single-valve arrangement is denitely preerredsince the operation o this type o diverter requiresthat someone go out and close the valve shortly aterthe rain begins, allowing the roo water to fow into thecistern. The valve should be located so that it can be

reached or controlled rom a covered porch or otherrooed area adjacent to the house or cistern.

During periods when rains are separated by onlybrie periods o time (less than a day), it is not neces-

sary to divert the initial roo wash every time it beginsto rain. However, it is important to divert the initialroo water produced by the rst rainall ollowingan extended dry period. This requires returning thediverter to the rinse position ollowing each storm toensure that dirty water isnt accidentally added to thecistern.

Determining how much roo water to allow to run

to waste beore routing it to the cistern will vary oreach storm. You can use the visual appearance o theroo water as an indicatori to your eye it runs clearwhen collected in a clear glass jar, you can direct thewater to the cistern or storage and subsequent use.Or you can place a large 10- to 20-gallon container un-der the downspout draining to waste. The containershould be sized to suit your particular roo area10gallons per 1,000 square eet o roo area.

At the beginning o a rainstorm, then, the dirtyroo water is directed into the container, and whenit is ull you know that the catchment has been su-ciently rinsed and the roo water can thereater be

routed to the cistern. For this type o arrangement, asingle roo-water collection vessel or the entire catch-ment is best. Adequate drainage, such as into a gravel-lled hole (well removed rom the cistern), should beprovided or the roo water that is to be wasted, wheth-er or not it passes through a collection vessel rst.

There are also automatic roo-wash diverters thatdo not require someones presence to operate at thestart o a rainstorm. The basic principle is the same.A certain quantity o contaminated roo water at thebeginning o a rainstorm is collected in a vessel so thatit cannot enter the cistern. Once the catchment hasbeen rinsed o by a

Documents

Pennsylvania; A Guide to Private Water Systems: A Manual for Rural Homeowners: On the Proper Construction and Maintenance of Private Wells, Springs, And Cisterns - Penn State University