Drinking Water Source Protection Report for the

City of Columbus Public Water System

The City of Columbus is a community public water system that voluntarily completed their

drinking water source assessment for their Parsons Road Wellfield under the Wellhead

Protection Program. The drinking water source protection areas for their surface water intakes

(at Dublin Road and Hap Cremean Water Plants) were completed by Ohio EPA.

Drinking Water Source Assessment for the City of Columbus (surface water intakes only)

(completed by Ohio EPA, 2003)

Wellfield Protection, Development and Management Plan (Parsons Road Wellfield) (completed by

Malcolm-Pirnie, 1988)

Drinking Water Source Assessmentfor the City of Columbus

Summary

Source Water Assessment andProtection.The following report for the City ofColumbus public water system (PWS) wascompiled as part of the Source WaterAssessment and Protection Program forOhio. This program is intended to identifydrinking water protection areas and provideinformation on how to reduce the risk ofcontamination of the waters within thoseareas. The goal of the program is to ensurethe long term availability of abundant andsafe drinking water for the present andfuture citizens of Ohio.

The Safe Drinking Water Act Amendmentsof 1996 established the national SourceWater Assessment and Protection Program,targeting all public water systems in theUnited States. A public water system is afacility that provides drinking water to 15 ormore service connections or that regularlyserves at least 25 people a day for at least60 days a year, whether from anunderground well or spring, or from anabove ground stream, lake, or reservoir. The requirement does not extend toresidential wells or cisterns. In Ohio thereare approximately 5,800 public watersystems.

Background. The City of ColumbusDivision of Water (DOW) operates acommunity public water system that servesa population of approximately 945,415people through more than 257,981 serviceconnections. Three drinking water plants,Dublin Road Water Plant, Hap CremeanWater Plant, and Parsons Avenue WaterPlant--comprise the Columbus public watersystem. The Dublin Road plant usessurface water from the Scioto River and theHap Cremean plant uses surface water from

Big Walnut Creek. These two systems arethe focus of this source water assessment.

The Parsons Avenue plant pumps groundwater from the sediments (primarily glacialdeposits of sand and gravel) of the SciotoRiver valley in south Columbus. The City ofColumbus’ Wellhead Protection Plan for thiswellfield is the equivalent of a drinking watersource assessment, and was fully endorsedby Ohio EPA in 1996. Therefore, theParsons Avenue plant is not addressed inthis report.

The Hap Cremean plant has the ability tosupplement the water supply at HooverReservoir with water from Alum CreekReservoir. Alum Creek source water wasassessed for the Del-Co/Alum Creek waterplant, and the source water information isavailable in that report.

The approved design capacity of the DublinRoad plant is 65 million gallons per day(mgd). In 2001, average production wasabout 52.58 mgd with a peak of 72.81 mgthat occurred on August 4. The approveddesign capacity of the Hap Cremean plant is100 mgd. In 2001, average production was73.12 mgd with a peak of 113.76 mg thatoccurred on June 29.

Protection Areas. The drinking watersource protection areas for the surfacewater sources are shown in the followingfigure. An inventory of all known oridentified potential contaminant sourceswithin the protection areas was conductedby DOW staff. Possible impacts to theDublin Road source water includeagricultural sources and point sources in theupper watershed, industrial activities in andadjacent to protection areas, storm water

runoff from developing areas and spills fromthe transportation network. Possibleimpacts to the Hap Cremean source watersinclude agricultural sources in thewatershed, storm water runoff fromdeveloping areas and spills from thetransportation network.

Protective Strategies. The ultimate goal ofsource water assessment is implementa-tion of protective strategies will betterprotect the drinking water source. Strategies for protecting the City ofColumbus’ source waters should includecontrolling runoff from agriculturalsources;controlling discharges fromindustrial and municipal point sources;controlling urban runoff from developingareas in the watershed and; coordinatingwith local emergency response agencies.

Ohio EPA encourages the City of ColumbusDOW to continue working with otherstakeholders in the source water protectionareas to develop a local protection plan thatwill protect the sources of drinking water. Many local watershed planning efforts areunderway to guide stream restoration andprotection activities which can also serve tobenefit the protection of drinking watersources. Ohio EPA recommends that a

Drinking Water Source Protection Team becreated to draft the plan and oversee itsimplementation. Some general guidance forthis effort has been provided with thisassessment report.

For More Information. Additionalinformation on protective strategies and howthis assessment was completed is includedin the detailed Drinking Water SourceAssessment Report for the City ofColumbus. Contact Gary Hannahs,Watershed Manager, City of Columbus,DOW to view a copy of the report at (614)645-1721.

Current information on the quality of thetreated water supplied by the City ofColumbus PWS is available in theConsumer Confidence Report (CCR). TheCCR is distributed annually and it reports ondetected contaminants and any associatedhealth risks from data collected during theprevious year. Consumer ConfidenceReports are available from the City ofColumbus website at:http://columbuswater.com/Consumer%20Confidence.htm or by contacting the WaterQuality Assurance Lab (WQAL) at (614)645-7691.

Summary Figure - Drinking water source protection areas (surface water) for theColumbus public water system.

Drinking Water Source Assessment

for the City of Columbus

Public Water System # 2504412

Franklin County

Prepared by:Ohio Environmental Protection Agency

Division of Surface WaterDivision of Drinking and Ground WatersCentral District Office and Central Office

December, 2003

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How to Use this Assessment

Clean and safe drinking water is essential to everyone. Protecting the source of drinking wateris a wise and cost-effective investment. The purpose of this source water assessment is toprovide information your community can use to develop a local Drinking Water ProtectionProgram. The Source Water Assessment benefits your community by providing the following:

• A basis for focusing limited resources within the community to protect thedrinking water source(s).The assessment provides your community with information regarding activities within theDrinking Water Source Protection Area that directly affect your water supply sourcearea. It is within this area that a release of contaminants, from a spill or improper usage,may travel through the watershed and reach the surface water intake. By examiningwhere the source waters are most sensitive to contaminants, and where potentialcontaminants are located, the assessment identifies the potential risks that should beaddressed first.

• A basis for informed decision-making regarding land use within the community.The assessment provides your community with a significant amount of informationregarding where your drinking water comes from (the source) and what the risks are tothe quality of that source. This information allows your community planning authoritiesto make informed decisions regarding proposed land uses within the protection area thatare compatible with both your drinking water resource and the vision of growthembraced by your community.

• A start to a comprehensive plan for the watershed and source water area.This assessment can be the beginning of a comprehensive plan for the water resource,one that addresses all of the uses the water resource provides. An ecologically healthylake, stream and watershed will provide a stable, high quality resource for drinkingwater.

For information about developing a local Drinking Water Source Protection Program, pleasecontact the Ohio EPA Division of Drinking and Ground Waters at (614) 644-2752 or visit theDivision’s web site at www.epa.state.oh.us/ddagw/pdu/swap.html.

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1.0 INTRODUCTION

The 1996 Amendments to the Safe Drinking Water Act established a program for states toassess the drinking water source for all public water systems. The Source Water Assessmentand Protection (SWAP) Program is designed to help Ohio’s public water systems protect theirsources of drinking water from becoming contaminated.

The purpose of this assessment is to identify where and how the source waters are at risk ofcontamination. The report• identifies the drinking water source protection area,• examines the characteristics of the watershed and water quality,• inventories the potential contaminant sources within that area, and discusses the

susceptibility of the system to contamination.

Finally, the report suggests actions that the public water supplier and local community may taketo reduce the risk of contaminating their sources of drinking water and ensure the long termavailability of abundant and safe drinking water resources.

Results and recommendations presented in this report are based on the information available atthe time of publication. Ohio EPA recognizes that additional information may become availablein the future that could be used to more accurately determine the drinking water sourceprotection area. Also, changes in land use may occur after Ohio EPA completes the potentialcontaminant source inventory. This report should be used as a starting point to develop a planto protect drinking water resources.

This report was prepared by Jeff Lewis, Linda Merchant-Masonbrink, and Rich McClay, OhioEPA, Division of Surface Water, with assistance from City of Columbus DOW staff.

2.0 PUBLIC WATER SYSTEM DESCRIPTION

Dublin Road Water Plant

The Dublin Road Water Plant is located near the center of Franklin County. It has a raw waterintake located on the Scioto River just south of the water plant. Griggs Reservoir, constructedin northwestern Franklin County in 1908, and O’Shaughnessy Reservoir, constructed insouthwestern Delaware County in 1925, provide the needed water supply on the Scioto Riverfor the Dublin Road Water Plant. The combined storage capacity of both reservoirs is about 6.2billion gallons.

The Dublin Road Water Plant’s treatment processes consist of two-stage treatment byflocculation and settling. First stage treatment includes alum addition for coagulation followedby second stage treatment using soda ash or caustic soda for softening. Treatment proceedswith recarbonation for stabilization, intermediate chlorination, filtration with anthracite cap filters,post chlorination, fluoridation and zinc orthophosphate for corrosion control. Potassiumpermanganate and powdered activated carbon are fed as needed for taste and odor control. Potassium permanganate is also fed on a seasonal basis for the removal of synthetic organicchemicals.

The Dublin Road Water Plant’s approved design capacity is 65 million gallons a day (mgd). For2001, average daily production was 52.58 mgd with a peak flow of 72.81 mgd that occurred onAugust 4.

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Hap Cremean Water Plant

The Hap Cremean Water Plant is located in northeastern Franklin County. It has a drinkingwater intake located on Big Walnut Creek just east of the water plant. Hoover Reservoir,constructed in northern Franklin County and southern Delaware County in 1955, provides themain water supply for the plant. The reservoir storage capacity is about 20 billion gallons ofwater.

The City of Columbus also maintains a 70 mgd raw water pump station at Alum Creek Reservoirto supplement the Hoover Reservoir water supply during periods of low flow. The pump stationprovides raw water through a force main that empties into the north west portion of HooverReservoir near Big Walnut Road. Most recently, the City of Columbus activated the raw waterpump station during the period from July 2002 to March 2003.

The Hap Cremean treatment process is similar to the Dublin Road two-stage treatment. Potassium permanganate and powdered activated carbon are also added for taste and odorcontrol. In addition, the Hap Cremean plant also feeds potassium permanganate on a seasonalbasis for the removal of synthetic organic compounds.

The Hap Cremean Water Plant’s approved design capacity is 100 mgd. For 2001, averagedaily production was 73.12 mgd with a peak flow of 113.76 that occurred on June 29, 2001.

3.0 DRINKING WATER SOURCE PROTECTION AREA

The Drinking Water Source Protection Area (protection area) for an inland stream is definedas the drainage area upstream of the point where the water is withdrawn from a surface sourcesuch as a stream, lake or reservoir. The protection area is subdivided into corridor andemergency management zones. An illustration of the protection areas and corridormanagement zones for the City of Columbus’ public water system is shown in Figure 1. Theemergency management zones are shown in Figures 2 and 3.

The Corridor Management Zone (CMZ) is an area along streams and tributaries within thesource water assessment area that warrants delineation, inventory, and management. Typically, this zone runs a total of ten miles upstream from the intake, and includes thetributaries that drain into it. The zone is 1,000 feet wide on each side of the Scioto River andAlum Creek mainstems (and the reservoirs), and 500 feet wide on each side of any tributaries.

The Emergency Management Zone (EMZ) is defined as an area in the immediate vicinity ofthe surface water intake, in which the public water system operator has little or no time torespond to a spill. The boundary of the EMZ is delineated in cooperation with the watersupplier. It typically is delineated as a semi-circle that extends 500 feet upstream of the intakeand 100 feet downstream of the intake.

The corridor and emergency management zones were the focus and field and windshieldsurveys to inventory potential contaminant sources. Information was also collected duringinterviews with water treatment plant personnel.

Dublin Road Water Plant Drinking Water Source Protection AreaFor the Dublin Road plant, the drinking water source protection area covers more than 1,000square miles and includes the upper Scioto River watershed. The protection area begins at theintake on the Scioto River near downtown Columbus and extends upstream to the headwatersseven miles north of Indian Lake in Hardin County. Major tributaries to the Scioto River in the

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protection area include Mill Creek and Bokes Creek. Griggs Reservoir and O’ShaughnessyReservoir provide more than 6.0 billion gallons of raw water storage for the Dublin Road. Griggs Reservoir covers more than 365 acres and has 15 miles of shoreline. O’ShaughnessyReservoir covers more than 1,000 acres and has 35 miles of shoreline. An illustration of theDublin Road protection area and CMZ is shown in Figure 1.

The CMZ portion of the Dublin Road protection area extends north along the Scioto River fromthe intake up to Griggs Reservoir in the northern portion of Franklin County for a distance of tenriver miles. Main tributaries included in the CMZ are Dry Run, Evans Run and Hayden Run.

Metropolitan areas located in the CMZ portion of the Dublin Road protection area includewestern Columbus, Grandview Heights, Hilliard, Upper Arlington and Dublin. Townshipslocated in the protection area include Franklin, Norwich, Washington, Clinton and Perry.

Figure 2 shows the boundary of the EMZ for the Dublin Road Water Plant’s protection area.

Hap Cremean Water Plant Drinking Water Source Protection AreaFor the Hap Cremean Plant, the protection area consists of more 195 square miles and includesthe upper Big Walnut Creek watershed. The Hap Cremean protection area begins at the intakeon Big Walnut Creek in northeast Columbus and extends to just south of Mount Gilead inMorrow County. Tributaries to Big Walnut Creek in the Hap Cremean protection area includeLittle Walnut Creek, Rattlesnake Creek, Duncan Run, Perfect Creek, Sugar Creek, Long Run,and Reynolds Run. An illustration of the Hap Cremean protection area and CMZ is shown inFigure 1.

The CMZ portion of the Hap Cremean protection area extends north along Big Walnut Creekfrom the intake up through Hoover Reservoir to the Village of Sunbury into the southern portionof Delaware County for a distance of about 17 river miles. The Hoover Reservoir portion of theHap Cremean protection area covers more 3,300 acres, has over 45 miles of shoreline andholds more than 20 billion gallons of water.

Metropolitan areas located in the CMZ portion of the Hap Cremean protection area includenortheast Columbus, Westerville (Franklin County), Galena and Sunbury (Delaware County). Townships located in the protection area include Blendon, Plain (Franklin County), Genoa,Harlem and Berkshire (Delaware County).

Figure 3 shows the boundary of the EMZ for the Hap Cremean Water Plant’s protection area.

4.0 HYDROLOGIC SETTING

Dublin Road Water Plant

Shape or Unique FeaturesThe Dublin Road Water Plant protection area is a hydrologic region of very strong land usecontrast, which influences source water protection considerations. Urban-suburban andagricultural land uses each present a different array of challenges to source water protectionwithin the spatial settings unique to the Dublin Road protection area. In shape, this protectionarea resembles a three pointed hat, with the points terminating in Hardin, Crawford and Franklincounties. The larger, central portion of the area lies in Union County.

Those portions of the area in Crawford, Hardin, Marion, Union and northern Delaware counties

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display overwhelmingly agricultural land uses, with an emphasis on corn and soybean farming. The portion in southern Delaware County and northern Franklin County transitions from“suburban” to densely populated urban, with a mix of residential, commercial, industrial andtransportation infrastructure land uses. Metropolitan Columbus contributes the largestcomponent of urban, suburban and currently developing land uses; smaller cities scatteredacross the protection area add similar acreage to the total. Bucyrus, Dublin, Hilliard, Kenton,Marion, Marysville and Upper Arlington are the larger examples.

A second notable feature of the protection area is the presence of two major reservoirs(O’Shaughnessy and Griggs) on the Scioto River in the suburban and developing sections ofthe area. In addition to impeding the flow of the Scioto River, they also intercept a number ofperennial and intermittent tributaries which flowed directly to the Scioto, prior to the reservoirs’construction. These include: Cramer Ditch, Hayden Run, Tudor Ditch, and Slate Run whichenter Griggs Reservoir, while Eversole Run and Mill Creek are the major perennial streamsentering O’Shaughnessy (United States Geological Survey).

Another feature is the presence of concentrated animal farm operations (CAFOs) in thisprotection area. Large-scale poultry, swine and dairy operations are present in the Union,Hardin and Marion county portions of the protection area.

A fourth notable characteristic observed in this protection area is the heavy concentration ofpotential contaminant sources in the lower portion (between the drinking water intake andGriggs reservoir). This portion of the watershed exhibits urban/suburban land uses withextensive impervious surface area and comparatively rapid run off to streams, ditches andstorm drains; often unimpeded by wooded or grassed riparian buffers.

Ecoregion - PhysiographyThe whole of the Dublin Road protection area has been glaciated and bears the marks of glacialdeposition, with an abundance of associated glacial soils. The area falls within the EasternCorn Belt Plains ecoregion and exhibits a variety of characteristic soils, geology, climate andoriginal vegetative cover.

That portion of the protection area extending from the intakes to approximately the DelawareCounty line rests within the Loamy High Lime Till Plains subset of the ecoregion. This subsetshows generally better draining soil associations formed on light to rolling glacial till plains withlow stream gradients, end moraines and glacial outwash forms. The remainder of the protectionarea falls within the Clayey High Lime Till Plains subset of the ecoregion exhibiting slowerpercolating soil associations, frequently requiring the artificial drainage of crop fields (Omernik,1988).

Topographic CharacteristicsIterative flows of glacial ice have marked Central Ohio with their characteristic land forms. TheDublin Road protection area shares this legacy. Depositional features (ground and endmoraines) are common and have influenced the area’s stream fall gradients and topography. Aclose reading of USGS topographic maps reveals end moraines with crowded contour linesindicating ridges.

While the highest stream fall gradients (222 and 275 ft./mile) on Scioto River tributaries areseen outside of this protection area, it should be noted that steep gradients are present in theDublin Road protection area. Both Slate Run in Franklin County and Deer Run in DelawareCounty exhibit falls greater than 125 ft./mile (Ohio Department of Natural Resources, 1960). Steep gradients may speed up pollutant transport from tributaries toward mainstem streams and

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intakes.

SoilsThe interaction of bedrock geology, slope-topography, flora, climate and the passage of timeproduced the soils of the Dublin Road protection area. The uplands throughout the protectionarea are generally not well drained, with the presence of Pewamo soil associations formed onglacial tills, as seen in Union and Delaware counties.

Throughout most of this area somewhat better draining soils formed in alluvium and glacialoutwash can be seen in the stream and river corridors (flood plain and terraces). These soilassociations can extend to approximately one mile for major tributaries such as Mill and BokesCreeks and up to approximately two miles in width for the Scioto.

Land UseLand use types typically exhibiting extensive impervious surfaces (commercial, industrial,transportation, low and high density residential) may rapidly introduce surface runoff intoprotection area waters through storm drains-sewers, ditches, old field tile systems and acrossparking lots, freeways, roads-streets and similar paved surfaces.

While land use data for the Dublin Road protection area compiled in 1992 indicate that theabove uses comprised approximately 4.5 percent of the total, that percentage has undoubtedlyincreased with the continued development of agricultural and rural acreage. It should also benoted that the percentage of developed land surface in the Franklin County portion of the studyarea (and in close proximity to the intake) well exceeds 4.5 percent and would be accompaniedby a near proportionate increase in impervious surface area. Portions of the Lower Olentangywatershed with similar development and land use exhibit between 41 percent and 78 percentimpervious surface (Friends of the Lower Olentangy Watershed 2003).

1992 data indicated that 72.7 percent of all land in the Dublin Road protection area is used forrow crop production. Pesticides and fertilizers can be introduced to the water column ofprotection area streams if applied improperly, exceeding recommended quantities or underunfavorable weather conditions. The absence of grassed or wooded riparian corridor and/orlack of conservation tillage practices may speed introduction of these pesticides to areastreams. The prevalence of grass lawns and their maintenance may introduce similar chemicalproducts into surface waters within the residential, commercial and industrial portions of thearea.

Transportation corridors and local roads which traverse or have close proximity to a CorridorManagement Zone (CMZ) can rapidly convey pollutants from spills to the stream system. Significant transportation infrastructure elements situated within or closely proximate to theDublin Road CMZ include, but are not limited to: I-270, I-70, I-670, U.S. Route 33, McKinleyAvenue, Grandview Avenue bridge, Trabue Road bridge, Fishinger Road bridge, Hayden Roadbridge, Conrail bridge at Marble Cliff, Conrail Buckeye rail yards south of Roberts Road, twoConrail lines running from northwest to southeast along the Scioto River between GrandviewAvenue bridge and Harrison Road, Camp Chase RR line extending from the southwest andintersecting the Conrail line south of the I-70 and I-670 intersection. I-270 crosses virtually alltributary streams within the CMZ west of the Scioto River (United States Geological Survey).

Surface runoffs from the above transportation network, “urban” runoff from driveways, parkinglots, roofs, patios and the likely improper disposal and leakage into storm drains and tributariesof home, business and industry byproducts (paints, lawn-garden chemicals, restaurant greases,soaps, cleaning products, vehicle lubricants, cleaning solvents) are commonly encountered inthe lower portion of the Dublin Road protection area.

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Runoff PotentialThe runoff potential from the Dublin Road protection area surfaces varies, in part, due toimperviousness, slope, soil characteristics and vegetative cover. Soil characteristics are moredeterminant in those portions of the area dominated by row cropping and pasture. Conservationtillage and wooded or grassed riparian corridors can mitigate these characteristics.

Imperviousness is more determinant in suburbanized and urbanized locations. Where land isundergoing “clearing”, surface shaping and other development related activity, properly installederosion protective measures such as seeding, silt fence, drain protection and holding ponds canmitigate the potentials of slope and soil type. These protective measures will in turn act to slowthe delivery of storm water to the stream network.

Soils are normally grouped into four hydrological classes: A, B, C, and D; from least to mostrunoff potential. The soil associations encountered in the rural and agricultural areas of thisprotection area (i.e. Glynwood-Blount) are classified C-C, exhibiting slow infiltration rates andcorrespondingly high runoff potential. These soils often require artificial drainage systems suchas field tile.

Certain soil associations (Milton-Ritchey) often seen in the Corridor Management Zone withinFranklin County are classified C-D, slow or very slow infiltration rates and correspondinglyhigher runoff potential (United States Department of Agriculture, Soil Conservation Service).

These soils in combination with one or multiple factors (heavy precipitation, rapid snow melt,frozen ground surface, steep stream gradients, impervious surfaces heavy tillage, absence ofriparian vegetative buffers) may contribute to more rapid introduction of pollutants to protectionarea water columns.

Hap Cremean Water Plant

Shape or Unique FeaturesThe Hap Cremean Water Plant’s protection area resembles an arrow head with the tip a fewmiles south of Mount Gilead. It widens downstream to include both the Alum Creek and HooverReservoirs with their constituent tributary systems. Notable features of this protection areainclude: • Two major stream systems drain the area: Alum and Big Walnut Creeks;• The reservoirs intercept most tributaries that previously would have flowed directly to Big

Walnut and Alum Creeks;• A golf course (Little Turtle), is located approximately two lineal miles upstream of the

intake and drained by an intermittent tributary to Big Walnut Creek; • A steep sided perennial tributary (100 foot relief) enters Big Walnut Creek approximately

2.3 linear miles upstream of the intake.

Ecoregion - PhysiographyThe Hap Cremean protection area overlaps three ecoregions (Omernik, 1988). South of theDelaware County line, the Big Walnut system flows across the Loamy High Lime Till Plainssubset of the Eastern Corn Belt Plains ecoregion. This rolling glacial till plain is characterizedby low gradient streams including Perfect and Culver Creeks. North of the Delaware Countyline, the Big Walnut system drains the landscapes of the Erie Ontario Drift and Lake Plain. These landscapes, on the eastern side of Big Walnut, show rolling plains, low rounded hills,gentle slopes, end moraines and typical outwash landforms. In Morrow County, the fewtributaries flowing from the west to the Big Walnut mainstem drain another subset of the EasternCorn Belt Plains ecoregion: the Clayey High Lime Till Plains. Also glaciated, this till plain area

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shows basins, end moraines and lower gradient streams.

Alum Creek Reservoir and all streams within the Corridor Management Zone (CMZ) lie withinthe Loamy High Lime Till Plains, a region of nearly level terrain. North of Indigo Creek’s mouthon Alum Creek, the protection area transitions to the slower draining Clayey High Lime TillPlains. Most of the Alum Creek tributaries flowing from higher elevations to the east (betweenFulton and the Morrow County line), drain a portion of the Erie/Ontario Drift and Lake Plain. This region of low rounded hills and scattered moraines and kettles shows more forested ridgesand lowlands than other portions of the Alum Creek drainage.

Topographic CharacteristicsIterative flows of glacial ice have marked Central Ohio with their characteristic land forms. Landscapes of the Hap-Cremean protection area share this legacy. Depositional features(ground moraines, end moraines etc.) are common and have influenced the area’s stream fallgradients and topography. Glacial till and outwash depositions are common. Many streamcourses are incised into these tills. The stream gradients are in part due to topographical reliefestablished by glaciation. However many former tributaries of Alum Creek now enter thereservoir and have as a result, modified gradients. (Alum Creek and its tributaries downstreamof the reservoir dam are not within this protection area.)

Big Walnut Creek and many of its tributaries are also reservoir-intercepted. Downstream of thedam four tributaries, two perennial and two intermittent, enter the mainstem. The first of these isa perennial stream entering Big Walnut through a steep sided ravine with relief approximating100 feet (Ohio Department of Natural Resources 1960).

SoilsThe interaction of bedrock geology, slope-topography, flora, fauna, climate and the passage oftime produced the soils encountered in this protection area. Drainage characteristics are onevariable affecting runoff potential within a protection area.

Within the Alum Creek portion of the protection area, two soil associations are dominant. Blount-Pewamo-Glynwood soils are seen on landscapes west of the Alum Creek reservoir,between Kilbourne and a DelCo Water Company intake. Shorter tributaries entering thereservoir between Peachblow Road and the dam, flow across Benington-Cardington-Pewamosoils. County soil surveys describe both soil associations as very slow, slow or moderately slowpermeating (US Department of Agriculture, Soil Conservation Service).

The protection area landscapes drained by Big Walnut and its tributaries show a variety of well,to very poorly draining soils. Uplands surrounding Hoover Reservoir show the somewhat poorlydrained to very poorly drained Bennington-Pewamo association formed in medium textured andfine textured glacial till.

The permeabilities and associated runoff characteristics of soils surrounding and upstream ofthe dam are less relevant than are those between the dam and the intake. The CMZ betweenthe dam and the intake exhibits the Medway-Genesee-Sloan association formed in recentalluvium. This later association includes well, to very poorly drained soils (United StatesDepartment of Agriculture, Soil Conservation Service).

Land UseLand use types typically exhibiting extensive impervious surfaces (commercial-industrial-transportation, low and high intensity residential) may rapidly introduce surface runoff into theHap-Cremean protection area waters through storm sewers, ditches, old field tile systems,parking lots and similar paved surfaces.

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The land use data referenced for the Hap-Cremean protection area (1992) indicate that theabove uses comprised approximately 1.3 percent of the total. This percentage has undoubtedlyincreased due to continued development of agricultural and rural acreage in the Big Walnut andAlum Creek watersheds. While scattered across various sections of these watersheds, landuses associated with extensive impervious surfaces are concentrated in the CMZ downstreamof Hoover Dam and in close proximity to the intake.

The 1992 data indicated that 50.7 percent of all land in this protection area was devoted to rowcrop production. Pesticides and fertilizers can be introduced to the water column of the Hap-Cremean protection area streams if applied improperly, exceeding recommended quantities orunder unfavorable weather conditions. The absence of grassed or wooded riparian corridorand/or lack of conservation tillage practices may speed introduction of these chemicals to areastreams. The prevalence of grass lawns and their maintenance may introduce similar chemicalproducts into surface waters within the residential, commercial and industrial portions of thearea

The recent intensive and coordinated focus on Big Walnut water quality by Columbus, CountySoil and Water Conservation Districts, the State of Ohio, the United States Department ofAgriculture and other entities has led to the increased implementation of water protectiveagricultural conservation practices, particularly upstream of Hoover Reservoir and dam.

Transportation corridors and local roads which traverse or have close proximity to a CMZ canrapidly convey pollutants from spills to the stream system. Significant transportationinfrastructure elements situated within or closely proximate to the Hap-Cremean CMZ include,but are not limited to: exit-entrance ramps of State Route 161 and Sunbury Road, State Route161 bridge, Central College Road and bridge, Sunbury Road and residential streets intersectingit from the east, Cherry Bottom Road and residential streets intersecting it from the west (UnitedStates Geological Survey).

Surface runoffs from the above transportation network, “urban” runoff from driveways, parkinglots, roofs, patios and the likely improper disposal and leakage into storm drains and tributariesof home, business and industrial byproducts (paints, lawn-garden chemicals, restaurant greasessoaps, cleaning products, vehicle lubricants, clean solvents) are commonly encountered in theintensely developed portion of the protection area between the Hoover Reservoir dam and theintake.

Runoff PotentialThe runoff potential observed within the Hap-Cremean protection area varies, in part, due toimperviousness, slope, soil characteristics and vegetative cover. Soil characteristics are moreimportant in those portions of the area dominated by row cropping and pasture. Conservationtillage and wooded or grassed riparian corridors can mitigate these characteristics.

Imperviousness will be more determinant in suburbanized and urbanized locations. Where landis undergoing “clearing,” surface shaping and other development related activity; properlyinstalled erosion protective measures such as seeding, silt fence, drain protection and holdingponds can mitigate the potentials of slope and soil type. These protective measures will in turnact to slow the delivery of storm water to the stream network.

Soils are normally grouped into four hydrological classes: A, B, C, and D; from least to mostrunoff potential. The soil associations encountered on the uplands of this SWAP area (i.e.Blount-Pewamo, Glynwood-Blount) are classified C exhibiting slow infiltration rates andcorrespondingly high runoff potential. The Medway-Genesee-Sloan associations encounteredon flood plains and terraces between the dam and the intake are classified B, moderateinfiltration rates and correspondingly lower runoff potential.

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When soils with high runoff potential are combined with other factors (heavy precipitation, rapidsnow melt, frozen ground surface, steep stream gradients, impervious surfaces, heavy tillage,absence of riparian vegetative buffer) they may contribute to more rapid introduction ofpollutants to SWAP area water columns.

ClimateFluctuating stream flows within the protection areas are partly a function of climate. Below thedam, the Big Walnut’s flow is strongly influenced by the US Army Corps of Engineers releaseschedule. Central Ohio lies within a climate region (Humid Continental) characterized by theinterface of cold-dry air masses from Canada and warmer, more humid air masses from the Gulfof Mexico (Strahler 1963). The meeting of contrasting air masses produces two predominantphenomena which may cause lengthy periods of precipitation or shorter period of more intenseprecipitation. They are: (1) the passing of warm and cold fronts which occurs throughout theyear; and (2) the development of convectional and frontal thunderstorms which are morefrequent in warmer months. Each may contribute to a rapid increase in runoff and stream flow,particularly in the presence of a frozen ground surface, saturated - slow draining soils and/orimpervious surfaces (Strahler 1963).

5.0 WATER QUALITY

Available chemical and biological water quality data collected from the streams in the protectionarea, and sampling results from finished water reported to Ohio EPA by the public watersupplier were evaluated to characterize the natural quality of the source waters (Scioto Riverand Little Walnut Creek).

Treated Water QualityA review of the City of Columbus’ compliance monitoring data from 1991-2002 revealed that thesystem has periodically detected nitrate and pesticides, as described below.

Dublin Road Water Plant (Scioto River). A review of sampling results for treated watersamples at the Dublin Road Plant (Table 1) indicates detections of several pesticides includingatrazine, alachlor, metolachlor, simazine, metribuzin, acetolochlor and cyanazine. Within thissampling period, only atrazine has ever exceeded its maximum contaminant limit (MCL), but thelevels and/or frequency have not been high enough to trigger an MCL violation. Atrazine hasbeen detected at levels as high as 3.89 ug/l (MCL is 3.0 ug/l).

Nitrates have been detected consistently in treated water samples. The maximum leveldetected during this time period was 15.3 parts per million. The MCL for nitrates is 10 parts permillion.

The Dublin Road Treatment Plant has been consistently in compliance with turbidityrequirements. The treatment technique requirements for turbidity must be maintained at lessthan or equal to 0.5 nephelometric turbidity units (NTU) in at least 95 percent of the samplesanalyzed. Turbidity monitoring helps indicate filtration effectiveness and high levels can be anindicator of soil runoff.

Hap Cremean Water Plant (Big Walnut Creek). A review of sampling results for treated watersamples at the Hap Cremean Plant (Table 2) indicates detections for several pesticidesincluding atrazine, alachlor, metolachlor, metribuzin, simazine and cyanazine. Within thissampling period, only atrazine has ever exceeded its maximum contaminant limit (MCL), but thelevels and/or frequency have not been high enough to trigger an MCL violation. Atrazine hasbeen detected at levels as high as 4.72 ug/l (MCL is 3.0 ug/l).

Nitrates have been detected consistently in treated water, but from 1991 to 2003 have not

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exceeded the MCL of 10 parts per million (mg/l). The maximum detected level was 5.7 partsper million.

The Hap Cremean plant has also been consistently in compliance with turbidity requirements.

It should be recognized that sampling results presented in this report can only provideinformation on the quality of water at the time the sample was collected. Water quality may overtime due to a number of reasons. Therefore, it is recommended that the reader also consult themost recent Consumer Confidence Report (CCR). Columbus is required annually to prepareand distribute the CCR to their customers. This report is a good source of information on thecommunity’s drinking water, including the source of the water, contaminants detected, the likelysources of detected contaminants, and the potential health effects of contaminants at levelsabove the drinking water standards. Consumer Confidence Reports are available from the Cityof Columbus website at: http://columbuswater.com/Consumer%20Confidence.htm or bycontacting the Water Quality Assurance Lab (WQAL) at (614) 645-7691.

Biological and Chemical MonitoringOhio EPA and the City of Columbus conduct extensive source water monitoring in the SciotoRiver and Big Walnut Creek watersheds. Included are ongoing biological and water qualitysurveys conducted by Ohio EPA to support the NPDES permitting process, total maximum dailyload (TMDL) program and other surface water activities. When conducting large surveys suchas these, sampling frequency and location may not be suitable to characterize specific goalssuch as those of the Drinking Water Source Protection program.

The City of Columbus source water monitoring activities are coordinated through the WatershedManagementnd stream water quality monitoring efforts in support of drinking water protectionactivities.

Summaries of some of these watershed monitoring activities are provided below.

Big Walnut Creek Watershed

< Biological and Water Quality Study of Big Walnut Creek and Selected Tributaries (Ohio EPA Technical Report MAS/2003 draft).

In 2000, Ohio EPA sampled more than twenty-five (25) sites in the Big Walnut watershedportion of the Hap Cremean protection area as part of the study. This included nine sites onthe Big Walnut Creek mainstem from Cardington-East Road (river mile 73.60) to State Route161 (river mile 34.90) just upstream of the Hap Cremean Water Plant (HCWP) intake. Tributaries of Big Walnut Creek in the Hap Cremean protection area that were sampled as partof the survey included Little Walnut Creek, Rattlesnake Creek, Prairie Run, Long Run, SugarCreek, Culver Creek, Dry Run, Perfect Creek and Duncan Run.

A review of the water quality sampling data collected from the 2000 survey indicates numerousexceedences of bacterial water quality standards throughout the Hap Cremean source waterprotection area. Included were exceedences of primary and secondary contact standards asmeasured by E. coli and fecal coliform. Several exceedences of the minimum dissolvedoxygen criteria were also identified. Other preliminary findings from the study include elevatedlevels of nutrients (ammonia, nitrates, phosphorus) and suspended solids in the source waterprotection area. These levels were often above the 75th percentile background value with somelevels even exceeding the 90th percentile.

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The completed report for the 2000 water quality survey should be consulted for additional data,results and discussion related the watershed quality in the Hap Cremean protection area. When completed, a hard copy will be available at the Ohio EPA’s web site at:http://www.epa.state.oh.us/dsw/document_index/psdindx.html.

< Big Walnut Creek TMDL

Water quality sampling in the Big Walnut watershed is expected to continue, to support OhioEPA’s total maximum daily load (TMDL) program. The proposed TMDL schedule for Big WalnutCreek includes additional field survey and stream sampling activities in 2003 with a projectedTMDL completion date of December 2003.

< Hoover Reservoir Water Quality Monitoring

The City of Columbus Water Quality Assurance Lab (WQAL) conducts monthly water qualitysampling of Hoover Reservoir. Nutrient levels and pesticides are analyzed to determine waterquality trends. Monthly sampling for nutrients (total phosphorus, nitrite/nitrates) in HooverReservoir showed slightly declining trends for the thirteen year period from 1990 - 2002. Forsampling conducted during the five year period from 1998 - 2002, total phosphorus levelsaveraged below 0.04 mg/l and nitrite/nitrate levels averaged below 1.5 mg/l.

Pesticide sampling for atrazine in Hoover Reservoir during the five year period from 1998 -2002averaged below 1.1 ug/l. The highest sample results recorded each year for atrazine were; 2.10ug/l (09/09/02), 2.67 ug/l (07/02/01), 4.81 ug/l (07/10/00), 2.02 ug/l (03/01/99), and 1.87(01/06/98). Simazine sample results for the same five year period averaged below 0.35 ug/l.The highest sample results recorded each year for simazine were; 0.81ug/l (07/01/02), 1.10(07/02/01), 1.56 ug/l (07/10/00), 0.38 ug/l (02/01/99) and 0.50 (01/06/98) (Columbus, 2003).

< Upper Big Walnut Creek CREP Water Quality MonitoringThe City of Columbus WQAL and Watershed Management Office also collects and analyzeswater quality data in support of the Upper Big Walnut Creek Conservation ReserveEnhancement Program (UBWC CREP). The UBWC CREP is a watershed effort to reducechemical and sediment runoff effort into Hoover Reservoir and tributaries. The CREPcompensates landowners who voluntarily take cropland out of production and establishconservation practices. Activities have included monitoring atrazine levels in Sugar Creek,Duncan Run and other streams in the watershed.

Scioto River Watershed

< Biological and Water Quality Study of the Upper Scioto River Basin (Ohio EPA TechnicalReport MAS/1996-12-13)

In 1995, Ohio EPA sampled more than thirty (30) sites in the Scioto River watershed portion ofthe Dublin Road Water Plant protection area as part of the study. This included 22 sites on theScioto River mainstem from upstream of Roundhead (river mile 233.6) to downstream ofO’Shaughnessy Reservoir (river mile 145.7). Twelve Scioto River tributary sites were sampled,including sites on Cottonwood Ditch, Taylor Creek, Silver Creek, Panther Creek and WildcatCreek. A majority of the sites sampled were in the Hardin and Marion County portion of theupper Scioto River watershed.

Overall, the study indicated that most sites studied met applicable biological and water qualityuse designations. Exceptions included the confluence of the Little Scioto River in the Prospectdam pool. The study showed concentrations of phosphorus and inorganic nitrogen werehighest at this location.

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Sampling immediately upstream and downstream of O’Shaughnessy Reservoir indicated fullattainment of aquatic life use standards. The study noted that some of the nutrient load fromthe Little Scioto River was assimilated by reservoir conditions. Water quality exceedences werenoted at rivermile 145.7 downstream of O’Shaughnessy Reservoir for copper and zinc. Urbanstorm water runoff from adjacent roads was indicated as the likely source.

The Biological and Water Quality Study of the Upper Scioto River Basin (Ohio EPA TechnicalReport MAS/1996-12-13) is available from Ohio EPA’s website at:http://web.epa.state.oh.us/dsw/documents/uscio95.pdf .

< Biological and Water Quality Study of Mill Creek (Scioto River Basin) and SelectedTributaries (Ohio EPA Technical Report MAS/1996-12-11)

In 1995, Ohio EPA sampled over 27 sites in the Mill Creek watershed portion of the Dublin Roadprotection area as part of this study. The Mill Creek study area is positioned from just upstreamof Otter Creek (river mile 39.4) and East Liberty in Logan County to the Mill Road Bridge (rivermile 1.8) near the confluence with the Scioto River in Delaware County. Most of the study areaand sampled sites were in Union County and included tributaries to Mill Creek (Town Run,Crosses Run, Blues Creek and Otter Creek).

Important water chemistry findings from this study showed elevated nitrate and phosphorusconcentrations extending from the Marysville Wastewater Treatment Plant (WWTP)downstream (approximately 18 miles) to the confluence with the Scioto River. Ammoniaexceedences of water quality standards criteria were also detected for about 1.5 milesdownstream of the WWTP.

The survey also showed numerous exceedences of bacterial water quality standards throughoutthe study area. Included were exceedences of primary and secondary contact standards asmeasured by fecal coliform. Most exceedences were found to be associated with point sourcedischargers (wastewater treatment plants), home sewage systems, agricultural runoff and othernonpoint sources.

Crosses Run drainage basin downstream from The Scotts Company (fertilizer productsmanufacturer) showed many water quality exceedences for pesticides. Included were aldrin,dieldrin, endrin, endosulfan I and II, heptachlor, DDT metabolites and a lindane isomer. Thestudy also found numerous semivolatile contaminants and highly elevated ammonia sampleresults in this area.

The Biological and Water Quality Study of Mill Creek (Scioto River Basin) and SelectedTributaries is available from Ohio EPA’s website at: http://web.epa.state.oh.us/dsw/documents/millma95.pdf.

< Biological and Water Quality Study of the Middle Scioto River and Alum Creek (OhioEPA Technical Report MAS/1997-12-12)

In 1996, Ohio EPA sampled seven sites on the mainstem of the Scioto River above the DRWPintake as part of this study. The sites were located beginning just upstream of Griggs Reservoir(River Mile 145) extending downstream to 5th Avenue (River Mile136).

Results from the 1996 water chemistry sampling portion of the study did not reveal significantwater quality problems in the Dublin Road protection area. Ammonia and nitrate-nitriteconcentrations were generally at or below median concentrations expected to be found in largeriver warm-water habitat reference sites. Total phosphorus concentrations were found generallybelow 0.2 mg/l (below warmwater habitat guideline of 1.0 mg/l). Fecal coliform was the mostfrequently exceeded water quality standard found in the Scioto River and source water

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protection area during the study. Reported sources included sewage spills, overflows, urbanrunoff and unsewered areas.

The Biological and Water Quality Study of the Middle Scioto River and Alum Creek is availablefrom Ohio EPA’s website at: http://web.epa.state.oh.us/dsw/documents/Scito96.pdf .

< Total Maximum Daily Loads for Mill Creek (Scioto River Basin) and Selected Tributaries(Ohio EPA Draft TMDL Report/2002)

In 2002, Ohio EPA completed the Total Maximum Daily Loads report for Mill Creek (Scioto RiverBasin) and Selected Tributaries. A TMDL is a calculation of the maximum amount of a pollutantthat a waterbody can receive and still meet water quality standards. The Mill Creek TMDLreport describes water quality and habitat conditions and assesses factors affecting waterquality standards attainment. The TMDL also provides a method for establishing importantrestoration options.

Much of this report is based on water quality survey data and other sampling collected by OhioEPA in 1990, 1995, 2000 and 2001. This report showed the primary causes on impairment inthe Mill Creek watershed are organic enrichment and low instream dissolved oxygen attributedto point source discharges and habitat degradation in some tributaries to Mill Creek.

TMDLs were calculated for CBOD5 and ammonia-N. Biological and habitat indices were alsodeveloped to support habitat restoration goals necessary to meet biological and chemical waterquality standards.

The Marysville WWTP was identified as the most significant source of impact to chemical waterquality and biological community performance in Mill Creek. This impact was attributed toorganic waste loadings (e.g. elevated ammonia, total phosphorus) and subsequent dissolvedoxygen depletion downstream. The Mill Creek TMDL report also identified The Scotts Companyas the primary source of impacts to Crosses Run. These impacts were related to ammonia,organic enrichment, low dissolved oxygen levels and contamination from pesticides and organiccompounds.

The main restoration options identified in this TMDL report are point source controls and habitatprotection and restoration. Additional options include septic system improvements, urban runoffcontrols and public education.

The Total Maximum Daily Loads for Mill Creek (Scioto River Basin) and Selected TributariesDraft Report is available from Ohio EPA’s website at:http://web.epa.state.oh.us/dsw/tmdl/MillCreekSciotoTMDLDraftReport_1002.pdf.

< Biological and Water Quality Study of Bokes Creek and Selected Tributaries (Ohio EPA Technical Report MAS/2000-12-7)

In 1999, Ohio EPA sampled more than 25 locations in the Bokes Creek watershed as part ofthis study. Bokes Creek is a tributary of the Scioto River in the Dublin Road source waterprotection area. The study area included 36 miles of Bokes Creek beginning at the mainstemreach at State Route 292 and extending downstream to the mouth near Warrensburg on theScioto River. Six tributaries to Bokes Creek, including Smith Run, Brush Run and PowderlickRun were also included in the study.

The study found that the entire Bokes Creek watershed is impacted by excessiveconcentrations of nutrients along with suspended solids, oxygen demanding substances andbacteria. Headwaters and tributaries were found to be severely influenced by agricultural runoff

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including fertilizers from grain producing fields and manure from livestock operations. Failingon-site wastewater treatment systems were also identified as problematic sources.

Phosphorus concentrations above the ecoregion reference site median of 0.13 mg/l were foundat most sites along the Bokes Creek mainstem and tributaries. Some phosphorus results wellabove 1.0 mg/l were noted in several of the tributaries sampled. Included were several resultsranging from 1.24 mg/l to 1.76 mg/l from sites studied in Powderlick Run.

Numerous exceedences of water quality standards for bacteria were found during the study. Included were exceedences of primary and secondary contact standards as measured by E. coliand fecal coliform.

Several organic pesticides or herbicides were detected in the Bokes Creek watershed studyarea. Included were concentrations of heptachlor, aldrin, dieldrin, and 4-4' DDT that allexceeded criterion for the prevention of chronic toxicity and human health water quality criteriafor nondrinking water. Heptachlor and atrazine were the most common substances detected. Atrazine was also found in ten of fourteen sample sites. All atrazine concentrations tentativelyidentified at sample sites were 1.0 ug/l or less.

The Biological and Water Quality Study of Bokes Creek and Selected Tributaries is availablefrom Ohio EPA’s website at: http://web.epa.state.oh.us/dsw/documents/BokesCrTSD.PDF.

< Total Maximum Daily Loads for Bokes Creek (Ohio EPA Draft TMDL Report/2002)

In 2002, Ohio EPA completed the Total Maximum Daily Loads (TMDL) report for Bokes Creek. A TMDL is a calculation of the maximum amount of a pollutant that a waterbody can receive andstill meet water quality standards. The Bokes Creek TMDL report describes water quality andhabitat conditions and assesses factors affecting water quality standards attainment. TheTMDL also provides a method for establishing important restoration options.

Much of this report is based on the Ohio EPA Biological and Water Quality Study of BokesCreek and Selected Tributaries (1999). This report determined the primary causes in the BokesCreek watershed are nutrient enrichment, low instream dissolved oxygen, sedimentation andhabitat degradation. TMDLs were calculated for total phosphorus. Biological and habitatindices were also developed to support habitat restoration goals necessary to meet biologicaland chemical water quality standards.

The major causes of impairment in the Bokes Creek watershed were nonpoint source in nature.Land application of manure from egg production facilities in the headwaters and tributaries,coupled with habitat degradation, other agricultural operations and failing or inadequate onsitesewage treatment facilities.

The main restoration options identified in the TMDL report include agricultural runoff controlstrategies, septic system and point source improvements, habitat restoration and publiceducation.

The Total Maximum Daily Loads for Bokes Creek Draft Report is available from Ohio EPA’swebsite at: http://web.epa.state.oh.us/dsw/tmdl/BokesCreekTMDLDraftReport_043002.pdf .

< Griggs Reservoir and O’Shaughnessy Reservoir Water Quality Monitoring

The City of Columbus Water Quality Assurance Lab (WQAL) conducts monthly water qualitysampling of Griggs and O’Shaughnessy Reservoirs in the DRWP source water protection area. Nutrient levels and pesticides are analyzed to determine water quality trends. Monthly sampling

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for nutrients (total phosphorus, nitrite/nitrates) in Griggs Reservoir showed a slightly increasingtrend for the thirteen year period from 1990 - 2002. For sampling conducted during the five yearperiod from 1998 - 2002 total phosphorus levels averaged below 0.16 mg/l and nitrite/ nitratelevels averaged below 3.80 mg/l. Monthly sampling for total phosphorus and nitrite/ nitrates inO’Shaughnessy Reservoir during the same 13-year period also showed a slightly increasingtrend. For sampling conducted during the five year period from 1998 - 2002 total phosphoruslevels averaged below 0.18 mg/l and nitrite/nitrate levels averaged below 4.20 mg/l.

Pesticide sampling for atrazine in Griggs Reservoir during the five year period from 1998 -2002averaged below 1.3 ug/l. The highest sample results recorded each year for atrazine were;10.76 ug/l (07/01/02), 1.05 ug/l (08/06/01), 5.47 ug/l (07/10/00), 1.04 ug/l (09/07/99), and 4.40(07/06/98). Simazine sample results in Griggs Reservoir for the same five year period averagedbelow 0.25 ug/l. The highest sample results recorded each year for simazine were; 2.56 ug/l(07/01/02), < 0.10 (multiple dates), 1.13 ug/l (07/10/00), 0.32 ug/l (03/01/99) and 0.83(07/06/98).

Pesticide sampling for atrazine in O’Shaughnessy Reservoir during the five year period from1998 -2002 averaged below 1.6 ug/l. The highest sample results recorded each year foratrazine were; 13.38 ug/l (06/03/02), 5.50 ug/l (06/04/01), 9.01 ug/l (06/05/00), 0.58 ug/l(06/07/99), and 2.30 (07/06/98). Simazine sample results in O’Shaughnessy Reservoir for thesame five year period averaged below 0.30 ug/l. The highest sample results recorded eachyear for simazine were; 3.12 ug/l (06/03/02), < 0.10 (multiple dates), 1.10 ug/l (06/05/00), 3.52ug/l (06/07/99) and 0.39 (07/06/98) (Columbus, 2003).

6.0 POTENTIAL CONTAMINANT SOURCES

A review of available regulated facility databases, including U.S. EPA’s Envirofacts, and fieldsurveys of the corridor management zone (CMZ) was conducted to identify potentialcontaminant sources present in the Hap Cremean and Dublin Road drinking water sourceprotection areas. This detailed inventory was conducted by Ohio EPA and City of ColumbusDivision of Water staff. Comprehensive field survey work was primarily completed by theWatershed Protection Specialists with the City of Columbus.

It is important to note that this inventory represents potential contaminant sources, and includesany source that has the potential to release a contaminant to surface or ground waters in theprotection area. It is beyond the scope of this study to determine whether any specific potentialsource is actually releasing a contaminant, or to what extent any potential source(s) may becontributing to the overall pollutant load.

It was noted during field surveys that storm sewers exist in much of the protection areas. Thestorm sewers may convey contaminants from potential sources located outside of the corridormanagement zone (CMZ). Future inventories may focus on identification and evaluation ofsources that are located outside the CMZ but next to storm sewers that enter source waterprotection areas.

Dublin Road Water Plant - Scioto River WatershedTable 3 provides a list of the potential contaminant sources for the Dublin Road protection area. These sources are also depicted in the Potential Contaminant Source Inventory (PSCI) Map(Figures 6 - 6c).

The inventory for the Dublin Road protection area includes more than 200 municipal,commercial and industrial sources. More than 180 of these sources are located inside thecorridor management zone (CMZ). No sources were found inside the emergency managementzone (EMZ). The PCSI includes more than 60 former petroleum leaking underground storage

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tank sites and more than 40 current Section 311 and 312 (SARA Title III) reporters of hazardoussubstances. The inventory also includes three inactive/closed landfill sites.

There are 12 NPDES permitted direct discharging facilities located in the Dublin Roadprotection area. Included is treated surface and storm water runoff from seven bulk petroleumfacilities located near Dry Run in the protection area. Other notable NPDES permitted facilitiesinclude a large rail yard complex, an asphalt emulsion manufacturer and a limestone aggregateproduction facility.

The PCSI contains a variety of industrial and commercial sources, including gas stations, fleet(bus/truck) terminals (more than 30), light to moderate manufacturing (metal fabrication,electronics, food processing), asphalt/concrete plants, junk yards, dry cleaners and auto repairshops. Some of the municipal, industrial and commercial sources were identified to have bulkchemical storage areas. The inventory reflects a protection area with sources and activitiescommon to most metropolitan or urban areas.

Hap Cremean Water Plant (HCWP) - Big Walnut Creek Watershed

Table 4 provides a list of the potential contaminant sources in the Hap Cremean protectionarea. These sources are also depicted in the Potential Contaminant Source Inventory (PSCI)Map (Figures 7 & 7a).

The inventory for the Hap Cremean protection area includes more than 60 municipal,commercial and industrial sources. More than 20 of these sources are located inside thecorridor management zone (CMZ). No sources were found inside the emergency managementzone (EMZ). The PCSI includes two NPDES municipal wastewater treatment plant dischargersand ten former leaking underground storage tank sites. Commercial sources located in the HapCremean protection area include gas stations, a farm chemical dealer, dry cleaners and autorepair shops. A few industrial (manufacturing) sources were identified, primarily in the Galenaand Sunbury portions of the protection area. Some of the municipal, industrial and commercialsources were identified to have bulk chemical storage areas.

No industrial NPDES permitted wastewater discharging facilities or closed/inactive landfills werefound to be in the protection area.

Overall, the inventory found the Hap Cremean protection area to be dominated by agriculturalland uses. Potential sources associated with these uses include row crop production andlivestock activities. Developing areas in the upper portion of the protection area indicategrowing commercial and residential land uses.

7.0 SUSCEPTIBILITY ANALYSIS

For the purposes of source water assessments, all surface waters are considered to besusceptible to contamination. By their nature, surface waters are open systems with noconfining layer to impede contaminant movement, and have relatively short travel times from thesource to the public water system intake. Based on the information compiled for thisassessment, the Columbus source water protection areas are susceptible to several sources ofpotential contamination. This information is provided below for the Dublin Road and the HapCremean protection areas.

Changing land uses in the protection areas may also result in new potential sources ofcontaminants. New residential, commercial and industrial development can be expected toincrease in the protection areas. This development will increase the amount of impervioussurfaces such as roofs, parking lots and roads in the protection area. Increases in theseimpervious surfaces can affect the transport of contaminants to the source water via direct

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runoff or through storm water collection systems. Contaminants such as metals, oil and grease,nutrients and pathogens are commonly transported in urban runoff. The transportation networkis a potential source of contamination through vehicular accidents that release hazardousmaterials.

It is important to note that this assessment is based on available data, and therefore, it may notreflect current conditions. Water quality, land uses, and other activities that are potentialsources of contamination may change with time. While the source water for the Columbuspublic water system is considered susceptible to contamination, historically, Columbus haseffectively treated this source water to meet drinking water standards with the occasionalexception of nitrate and atrazine.

Dublin Road Protection AreaThe Dublin Road protection area is particularly susceptible to spills via the transportationnetwork. Much of the Dublin Road corridor management zone (CMZ) is located in the greaterColumbus metropolitan area. The transportation network in this area is significantly developedwith many different types and volumes of cargo being carried.

Interstate 270 is a designated hazardous materials route with more than eight miles of thewestern portion of the highway in or immediately adjacent to CMZ areas. There are alsoseveral major bridge crossings in the source water protection area including Interstate 670,Trabue Road, Fishinger Road, Hayden Run Road, Dublin-Granville (State Route 161) Road andInterstate 270. Interstate 70 storm water control includes a 4,000 gpm pump station thatdischarges into Dry Run during storm events just upstream of the intake.

Several miles of rail lines, including Conrail and CSX, are located in or adjacent to CMZ areas.The large Conrail Buckeye Yards rail complex off Trabue Road and drained by Trabue Run alsorepresents a source of contamination through spills and storm water run-off.

The Dublin Road protection area is also susceptible to spills and releases from industrial pointsources located in the source water protection area. Included are the bulk petroleum storagefacilities located near Dry Run in the western portion of the source water protection area. Thesefacilities discharge storm water and other wastewaters to Dry Run which flows into the SciotoRiver just above the Dublin Road protection area intake.

Untreated sewage releases from the City of Columbus sanitary sewer system in the DublinRoad protection area also represent a risk to the water supply. These sewage releases includesanitary sewer overflows (SSOs). Sewage releases can cause pathogen impacts andincreased nutrient loading. Unsewered areas (on-site septic systems) may also be a concern inthe protection area.

Nonpoint source (NPS) pollution from agricultural activities is a contributor of nutrient andagricultural chemical loading (e.g. pesticides) in the upper Scioto River portion of the DublinRoad protection area. Identified sources include several egg farms and other concentratedanimal feeding operations located in the Mill and Bokes Creek watersheds. These operationscan be the source of significant nutrient loading as well as sediment and bacteria contaminantsin the watershed.

Atrazine loading from row crop agriculture is also well documented in the source waterprotection area. Other sources of contamination located in this upper portion of the DublinRoad protection area include nonpoint source impacts from a large fertilizer manufacturer andmunicipal wastewater treatment discharges in Marysville.

Nonpoint source impacts from construction and development activity in the Dublin Roadprotection area also represent risk. This activity increases the susceptibility of the Dublin Road

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protection area to impacts from heavy siltation, metals and oil and grease, nutrients andpathogen run-off. The western portion of Franklin County and southern portion of DelawareCounty are two of the more rapidly developing portions of the Dublin Road drinking watersource protection area.

Hap Cremean Protection AreaThe Hap Cremean protection area is susceptible to impact largely due to agricultural activities inthe upper Big Walnut Creek watershed portion of the Hap Cremean source water protectionarea. These activities include row crop agriculture and livestock operations that dominate thisportion of the source water protection area. Nonpoint source runoff containing sediment,nutrients and agricultural chemicals (including atrazine) have caused water quality concerns inthe watershed. These impacts are well documented and are the focus of current source waterprotection efforts (e.g. Upper Big Walnut Creek Conservation Reserve Enhancement Program).

Nonpoint source impacts from construction and development activity in the Hap Cremeanprotection area also represents risk. This activity increases the susceptibility of the sourcewater protection area to impact from heavy siltation, metals and oil and grease, nutrients andpathogen run-off. The southern portion of Delaware County is one of the more rapidlydeveloping portions of the Hap Cremean protection area.

The Hap Cremean protection area is susceptible to spills in the source water protection area viathe transportation network including Interstate 270 and State Routes 3 and 36/37. Interstate270 is a designated hazardous materials route with more than one mile of the northeast portionof the highway in or immediately adjacent to the CMZ and just immediately upstream of theEMZ and intake. There are also several major bridge crossings in the source water protectionarea, including State Route 161, Smothers Road, Sunbury Road (two crossings), State Route36 and State Route 37. Frequent fuel (e.g. gas stations, home fuel oil) and agriculturalchemical (e.g. anhydrous ammonia) deliveries are common in the source water protection area.

Point sources located in the Hap Cremean protection area also represent some risk. Thesesources include two municipal wastewater treatment plants (Galena, Sunbury) located just northof Hoover Reservoir in the Hap Cremean protection area. Other sources, including on-sitehome sewage treatment and disposal systems and commercial sources, represent a reducedrisk.

8.0 PROTECTIVE STRATEGIES

Protective strategies for public water systems and source water protection areas typically fallinto one or more of the following three categories: education, training and public participation;emergency response/contingency planning; and potential contaminant source control strategies. The City of Columbus has been actively involved in these and many other types of watershedprotection efforts for the DRWP and Hap Cremean source water protection areas. Notableprotective strategies currently used in the Columbus source water protection areas include;

• Land Stewardship Program; The Division of Water has established a program to workwith the nearly 1,200 residential landowners living contiguous to the Hoover,O’Shaughnessy and Griggs Reservoirs. Primary goals of this program include elimination ofencroachments, implementation of best management practices along the waterways, andsecuring land stewardship agreements. Land stewardship agreements are personalizedcontracts with the contiguous landowners which give permission for limited landscapemanagement on city-owned riparian land. This outreach program is succeeding throughpersonal contact and landowner education on best management practices. Prior to this

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program, many landowners were maintaining mown lawns to the water’s edge and erodiblepaths. Now, landowners are mowing less, establishing buffer zones of grasses and nativeplants to slow run-off, and minimizing impact to the riparian corridor. This program,established in 1996 is improving through the use of databases, documentation of landconditions and photographic records of land-use changes.

• Agricultural Programs; With agriculture as the primary land use in the Big Walnut CreekWatershed, the Division of Water has actively pursued programs to reduce erosion,pesticide and nutrient loading into Hoover Reservoir. The Big Walnut Creek Water QualityPartnership is a volunteer consortium representing producers, and agencies including Cityof Columbus, Soil and Water Conservation Districts, ODNR, Ducks Unlimited, PheasantsForever and USDA. A variety of voluntary incentive programs encourage best managementpractices (BMPs) such as filter strips, riparian buffers, tree plantings and wildlife habitat. In2002, the Partnership was instrumental in establishing a Conservation ReserveEnhancement Program (CREP) for the Big Walnut Creek Watershed. This programprovides more than $13 million in financial incentives to farmers and other landowners toestablish important watershed protection activities with a goal of enrolling 3,500 acres intoconservation practices. The Division of Water has contributed funds and in-kind services tosupport these programs.

In addition to CREP, the Big Walnut Creek Water Quality Partnership facilitates enrollmentin the Environmental Quality Incentive Program (EQIP) program which has enrolled morethan 28 thousand acres of land in Delaware and Morrow counties between 1998 and 2002. This program minimizes atrazine use through use of alternative herbicides. The Division ofWater has also established funds for perpetual conservation easements. Interest in theseeasements is being pursued with a large egg farm operation in the Scioto River Watershed,as well as from individual landowners who do not qualify for conservation programs likeCREP.

Currently work is underway to establish a CREP in the Scioto River Watershed. With amuch larger watershed drainage area, the Scioto CREP is a challenge for the manystakeholders, including the Division of Water, but progress is being made.

• Watershed Ranger Staff; The Division of Water, Watershed Management Section employseleven Water Protection Specialists, commonly known as Watershed Rangers. Two shiftsof Rangers patrol the watershed areas using boats, vehicles, and foot patrol to identifypotential sources of contamination. They maintain and secure the city-owned land andfacilities surrounding the reservoirs and serve as contact points for the public. Dutiesinclude regular and special water sampling, various educational efforts, monitoring ofcontiguous properties, and cooperation with law enforcement, and other agencies torespond to violations of park and reservoir rules and regulations.

• Public Outreach at Special Events; All three reservoirs are popular recreationdestinations for central Ohio. Watershed Rangers participate in the annual “Boat Show” andthe “Sports, Vacation and Travel Show,” both held at the Ohio State Fairgrounds. Bystaffing an information booth with various brochures and computerized slide show, therangers educate attendees on the water quality impacts of boating, and park rules andregulations (many of which are based on a water quality preservation concept).

• Reservoir Litter Clean-ups; Every year, two litter clean ups are organized by theWatershed Management Section at Hoover and O’Shaughnessy Reservoirs. The clean-upsattract recreational users, scouts, school groups, and neighbors, with some year's

21

participation totaling 400 volunteers. Gloves, bags and refreshments are provided for thevolunteers who collect litter from the banks and public access areas around the reservoir. The spring clean-up is held in conjunction with other area clean-ups in the Big Walnut Creekand Scioto River Watersheds to celebrate River Pride Week.

Other strategies Columbus may consider for source water protection include:

‘ Continue to coordinate emergency planning efforts with the Delaware County LocalEmergency Planning Committee (LEPC) and the Franklin County LEPC to ensure sourcewater protection is considered in LEPC hazardous material spill responses;

‘ Continue to ensure procedures are in place with LEPCs and other emergency responders(including local fire department personnel) to ensure early notification from facility andtransportation spills/releases in the source water protection areas;

‘ Consider conducting a more detailed evaluation (e.g. GIS mapping, field inventory) of stormwater conveyances and specific land use activities in and adjacent to corridor managementzones.

‘ Continue conducting periodic inventories for potential contaminant sources, includingcommercial and industrial uses, located in the source water protection areas.

‘ Integrate source water protection efforts with the City of Columbus Municipal SeparateStorm Sewer System (MS4) Program. Included are efforts for identifying major storm wateroutfalls and sources, reducing pollutants from industrial, commercial and residential areas,and controlling storm water from new development.

‘ Continue collecting data on water quality conditions in the source water protection area toidentify pollutant trends, prioritize protective strategies and evaluate effectiveness ofprotection efforts.

Ohio EPA encourages the City of Columbus to incorporate the types of protective strategieslisted above into a written drinking water source protection plan. Two guidance documents areavailable from Ohio EPA to assist with development of a Drinking Water Source Protection Plan. A Guide to Developing Local Watershed Action Plans in Ohio is available on the internet atwww.epa.state.oh.us/dsw/hps/wsguide.pdf and Developing Local Drinking Water SourceProtection Plans in Ohio is available at www.epa.state.oh.us/ddagw/pdu/swap_psdoc.pdf. Formore information on drinking water source protection, please contact the Drinking WaterProtection staff at (614) 644-2752.

References

Friends of the Lower Olentangy Watershed. 2003. The Lower Olentangy Watershed ActionPlan in 2003.

Ohio EPA. 1999. Biological and Water Quality Study of the Middle Scioto River and AlumCreek. Franklin, Delaware, Morrow and Pickaway Counties. Division of Surface Water. Ecological Assessment Unit.

Ohio Department of Natural Resources. 1960. Gazetteer of Ohio Streams, Division of Water.Ohio Water Plan Inventory Report No. 12

22

Omernik, J.M. and A.L. Gallant. 1988. Ecoregions of the Upper Midwest States. EPA/600/3-88/037. U.S. Environmental Protection Agency, Environmental Research Laboratory, Corvallis,Oregon. 56pp.

Strahler, A.N. 1963. Physical Geography. John Wiley and Sons, Inc. New York 534 pp.

United States Department of Agriculture, Soil Conservation Service. In Cooperation with OhioDepartment of Natural Resources, Division of Lands and Soil and the Ohio AgriculturalResearch and Development Center. Soil Survey of Delaware County. Soil Survey of UnionCounty. Soil Survey of Franklin County.

United States Geological Survey. Galena, New Albany, Northeast Columbus, NorthwestColumbus, Southwest Columbus Quadrangles; Ohio. 7.5 minute series (topographic).

23

Table 1 - Water Quality Monitoring Summary of Treated Water City of Columbus Dublin Road Water Plant

Ohio EPA Public Water System Compliance Monitoring Database (1991- 2003)Ohio EPA Pesticide Special Study (May 1995 - March 1999)

Contaminant(units)

LevelsFound

PrimaryMCL

MCLViolation 1 Typical Source

Inorganic Contaminants

Barium (mg/l) 0.012 - 0.016 2 No Discharge of drilling wastes; Discharge frommetal refineries; Erosion of natural deposits

Copper (mg/l) 0.007 AL=1.3 NoCorrosion of household plumbing systems;Erosion of natural deposits; Leaching fromwood preservatives

Fluoride (mg/l) 0.91 - 1.02 4 NoErosion of natural deposits; Water additivewhich promotes strong teeth; Discharge fromfertilizer and aluminum factories

Nitrate (mg/l) 0.2 - 15.3 10 No Runoff from fertilizer use; Leaching from septictanks, sewage; Erosion of natural deposits

Phosphorus (mg/l) 0.39 - 0.63 none NARunoff from fertilizer use; Leaching from septictanks, sewage; Erosion of natural deposits;Discharge of industrial waste

Selenium (µg/l) 2 50 NoDischarge from petroleum and metalrefineries; Erosion of natural deposits; Discharge from mines

Sulfate (mg/l) 100 - 113 none NA2

Erosion of natural deposits; decompositionproduct of organic matter; discharge frommining and industrial waters; detergents insewage; component of precipitation inmetropolitan areas

Radioactive Contaminants Beta/photon emitters (pCi/L) 4.2 - 8.5 AL=50 No Decay of natural and man-made depositsSynthetic Organic Contaminants including Pesticides and Herbicides

Alachlor 3 (µg/l) 0.07 - 0.54 2 No Herbicide runoff

Atrazine 3 (µg/l) 0.11 - 3.89 3 No Herbicide runoff

Metolachlor 3 (µg/l) 0.08 - 3.63 none NA Pesticide runoff

Metribuzin 3 (µg/l) 0.04 - 0.47 none NA Pesticide runoff

Simazine 3 (µg/l) 0.10 - 1.72 4 No Herbicide runoff

Cyanazine 3 (µg/l) 0.08 - 3.41 none NA Pesticide runoff

Acetochlor 3 (µg/l) 0.55 none NA Herbicide runoff

Volatile Organic Contaminants TTHMs [TotalTrihalomethanes] (µg/l) 17.6 - 99.8 80 No4 By-product of drinking water chlorination

Bromodichloromethane (µg/l) 0.7 - 23.7 none NA4 By-product of drinking water chlorination

Chloroform (µg/l) 6.75 - 103.3 none NA4 By-product of drinking water chlorinationBromoform (µg/l) 0.6 - 2.7 none NA4 By-product of drinking water chlorinationDibromochloromethane (µg/l) 0.52 - 14.1 none NA4 By-product of drinking water chlorination

Dibromoacetic Acid (µg/l) 1.0 - 4.2 none NA4 By-product of drinking water chlorination

Table 1 - Water Quality Monitoring Summary of Treated Water City of Columbus Dublin Road Water Plant

Ohio EPA Public Water System Compliance Monitoring Database (1991- 2003)Ohio EPA Pesticide Special Study (May 1995 - March 1999)

Contaminant(units)

LevelsFound

PrimaryMCL

MCLViolation 1 Typical Source

24

Dichloroacetic Acid (µg/l) 6.6 - 37.5 none NA4 By-product of drinking water chlorinationTrichloroacetic Acid (µg/l) 4.6 - 27.8 none NA4 By-product of drinking water chlorinationMonobromoacetic Acid (µg/l) 0.3 -2.3 none NA4 By-product of drinking water chlorinationMonochloroacetic Acid (µg/l) 1.0 - 5.9 none NA4 By-product of drinking water chlorination

MCL = Maximum Contaminant Level (AL = Action Level).

1 MCL set by federal or state drinking water standards. A sampling result that exceeds the MCL value does notnecessarily indicate a violation by the public water system. MCL violations for many contaminants are based ona running annual average.

2 Secondary Maximum Contaminant Level (SMCL) for this parameter. SMCLs are non-health-related limits.

3 Data includes Ohio EPA Pesticide Special Study results (1995-1999). For the study, samples were analyzed usingan immunoassay (IA) method and by USEPA Method 507, a gas chromatograph (GC) method. The immunoassayresults are only estimations of the actual concentration values. The IA test kits tend to overestimate concentrations,due to cross reactivity of chemically similar pesticides (e.g. atrazine and simazine).

4 Total Trihalomethanes (TTHMs): (MCL = 80 µg/l) calculated as the sum of the concentrations ofBromodichloromethane, Dibromochloromethane, Bromoform, and Chloroform. Five Haloacetic Acids (HAA5): (MCL =60 µg/l) calculated as the sum of the concentrations of Monochloroacetic acid, Dichloroacetic acid, Trichloroaceticacid, Monobromoacetic acid, and Dibromoacetic acid.

25

Table 2 - Water Quality Monitoring Summary of Treated Water City of Columbus Hap Cremean Water Plant

Ohio EPA Public Water System Compliance Monitoring Database (1991- 2003)Ohio EPA Pesticide Special Study (May 1995 - March 1999)

Contaminant(units)

LevelsFound

PrimaryMCL

MCLViolation 1 Typical Source

Inorganic Contaminants

Barium (mg/l) 0.019 - 0.020 2 No Discharge of drilling wastes; Discharge frommetal refineries; Erosion of natural deposits

Copper (mg/l) 0.004 AL=1.3 NoCorrosion of household plumbing systems;Erosion of natural deposits; Leaching fromwood preservatives

Fluoride (mg/l) 0.2 - 1.0 4 NoErosion of natural deposits; Water additivewhich promotes strong teeth; Discharge fromfertilizer and aluminum factories

Lead (µg/l) 3.0 AL=15 No Corrosion of household plumbing systems;Erosion of natural deposits

Nitrate (mg/l) 0.4 - 5.7 10 No Runoff from fertilizer use; Leaching from septictanks, sewage; Erosion of natural deposits

Phosphorus (mg/l) 0.33 - 0.59 none NARunoff from fertilizer use; Leaching from septictanks, sewage; Erosion of natural deposits;Discharge of industrial waste

Sulfate (mg/l) 60 none NA2

Erosion of natural deposits; decompositionproduct of organic matter; discharge frommining and industrial waters; detergents insewage; component of precipitation inmetropolitan areas

Radioactive Contaminants Beta/photon emitters (pCi/L) 4.0 - 6.8 AL=50 No Decay of natural and man-made depositsSynthetic Organic Contaminants including Pesticides and Herbicides

Alachlor 3 (µg/l) 0.03 - 1.67 2 No Herbicide runoff

Atrazine 3 (µg/l) 0.11 - 4.72 3 No Herbicide runoff

Metolachlor 3 (µg/l) 0.22 - 2.26 none NA Pesticide runoff

Metribuzin 3 (µg/l) 0.14 - 0.24 none NA Pesticide runoff

Simazine 3 (µg/l) 0.09 - 0.92 4 No Herbicide runoff

Cyanazine 3 (µg/l) 0.07 - 1.65 none NA Pesticide runoff

Volatile Organic Contaminants TTHMs [TotalTrihalomethanes] (µg/l) 24.0 - 108.4 80 No4 By-product of drinking water chlorination

Bromodichloromethane (µg/l) 1.2 - 17.8 none NA4 By-product of drinking water chlorination

Chloroform (µg/l) 9.46 - 119.6 none NA4 By-product of drinking water chlorinationBromoform (µg/l) 0.5 - 3.1 none NA4 By-product of drinking water chlorinationDibromochloromethane (µg/l) 0.59 - 61.0 none NA4 By-product of drinking water chlorination

Dibromoacetic Acid (µg/l) 0.3 - 1.0 none NA4 By-product of drinking water chlorinationDichloroacetic Acid (µg/l) 10.1 - 37.7 none NA4 By-product of drinking water chlorination

Table 2 - Water Quality Monitoring Summary of Treated Water City of Columbus Hap Cremean Water Plant

Ohio EPA Public Water System Compliance Monitoring Database (1991- 2003)Ohio EPA Pesticide Special Study (May 1995 - March 1999)

Contaminant(units)

LevelsFound

PrimaryMCL

MCLViolation 1 Typical Source

26

Trichloroacetic Acid (µg/l) 6.6 - 26.2 none NA4 By-product of drinking water chlorinationMonobromoacetic Acid (µg/l) 0.1 - 3.4 none NA4 By-product of drinking water chlorinationMonochloroacetic Acid (µg/l) 1.2 - 10.4 none NA4 By-product of drinking water chlorination

MCL = Maximum Contaminant Level (AL = Action Level).

1 MCL set by federal or state drinking water standards. A sampling result that exceeds the MCL value does notnecessarily indicate a violation by the public water system. MCL violations for many contaminants are based ona running annual average.

2 Secondary Maximum Contaminant Level (SMCL) for this parameter. SMCLs are non-health-related limits.

3 Data includes Ohio EPA Pesticide Special Study results (1995-1999). For the study, samples were analyzed usingan immunoassay (IA) method and by USEPA Method 507, a gas chromatograph (GC) method. The immunoassayresults are only estimations of the actual concentration values. The IA test kits tend to overestimate concentrations,due to cross reactivity of chemically similar pesticides (e.g. atrazine and simazine).

4 Total Trihalomethanes (TTHMs): (MCL = 80 µg/l) calculated as the sum of the concentrations ofBromodichloromethane, Dibromochloromethane, Bromoform, and Chloroform. Five Haloacetic Acids (HAA5): (MCL =60 µg/l) calculated as the sum of the concentrations of Monochloroacetic acid, Dichloroacetic acid, Trichloroaceticacid, Monobromoacetic acid, and Dibromoacetic acid.

27

Table 3 - Potential Contaminant Source Inventory for the Columbus-Dublin Road Drinking Water Source Protection Area [Map ID number corresponds to Figures 6, 6A, 6B and 6C]

Map ID Unique ID Facility Description Data Source

101 RIP0009 Hazardous waste site with groundwater monitoring

OEPA RIPFLEX Database

102 OHD982622508 Commercial/Industrial US EPA Envirofacts - RCRIS

103 LUST252293700 Underground Storage Tank BUSTR: LUST database

104 OHD022556930 County Services US EPA Envirofacts - RCRIS

105 LUST253027900 Underground Storage Tank BUSTR: LUST database

106 LUST253097100 Underground Storage Tank BUSTR: LUST database

107 OHD982610594 City Services US EPA Envirofacts - RCRIS/NPDES

108 OHD986966380 City Services US EPA Envirofacts - RCRIS

109 SIM0594 Settling Pond OEPA-DSW Surface Impoundment GISLayer

110 LUST251096600 Underground Storage Tank BUSTR: LUST database

111 OHD980617054 Commercial US EPA Envirofacts - RCRIS

112 LUST250240800 Underground Storage Tank BUSTR: LUST database

113 LUST025942700 Underground Storage Tank BUSTR: LUST database

114 LUST250116000 Underground Storage Tank BUSTR: LUST database

115 Foundries & metal fabricators Field Survey

116 Foundries & metal fabricators Field Survey

117 OHD017874173 Commercial US EPA Envirofacts - RCRIS

118 Landscaping firms Field Survey

119 OH0001859156 Automotive Services US EPA Envirofacts - RCRIS

120 LUST251170100 Underground Storage Tank BUSTR: LUST database

121 OHD987032893 Automotive Services US EPA Envirofacts - RCRIS

122 Junk yards Field Survey

123 Foundries & metal fabricators Field Survey

124 Junk yards Field Survey

125 LUST252030900 Underground Storage Tank BUSTR: LUST database

126 OHD065996688 City bus depot US EPA Envirofacts - RCRIS

127 LUST250062300 Underground Storage Tank BUSTR: LUST database

128 LUST254093200 Underground Storage Tank BUSTR: LUST database

Map ID Unique ID Facility Description Data Source

28

129 LUST251325100 Underground Storage Tank BUSTR: LUST database

130 Foundries & metal fabricators Field Survey

131 Junk yards Field Survey

132 LUST254042300 Underground Storage Tank BUSTR: LUST database

133 Equipment Rental/Repair shops Field Survey

134 LUST252032600 Underground Storage Tank BUSTR: LUST database

135 OHD017911546 Commercial/Industrial US EPA Envirofacts - RCRIS

136 LUST251130600 Underground Storage Tank BUSTR: LUST database

137 LUST250220500 Underground Storage Tank BUSTR: LUST database

138 Junk yards Field Survey

139 Junk yards Field Survey

140-142 RIP0014OHD081313744

Hazardous waste site with groundwater monitoring

OEPA RIPFLEX Database US EPA Envirofacts - RCRIS/DOCKET

143 125-1392 Commercial Ohio EPA-DERR MSL GIS layer

144 OHD986966331 Pumping Station US EPA Envirofacts - RCRIS

145 LUST255018500 Underground Storage Tank T BUSTR: LUST database

146 OH0000923078 Automotive Services US EPA Envirofacts - RCRIS

147 LUST256124100 Underground Storage Tank BUSTR: LUST database

148 OHD047979976 Commercial/Industrial US EPA Envirofacts - RCRIS

149 LUST250278200 Underground Storage Tank BUSTR: LUST database

150 Commercial SARA III

151 AIR0001 Heliport USGS Geonames

152 Print shops/Photo shops Field Survey

153 LUST025946000 Underground Storage Tank BUSTR: LUST database

154 OHD987044856 Residence US EPA Envirofacts - RCRIS

160 Commercial SARA III

163 LAN0032 Inactive/Closed Landfill OEPA Landfill GIS Layer

164 OHD980995146 Training Academy US EPA Envirofacts - RCRIS

165 LUST251096500 Underground Storage Tank BUSTR: LUST database

166 OHD987000775 Commercial/Industrial US EPA Envirofacts - RCRIS

167 Food processor Field Survey

168 LUST255163600 Underground Storage Tank BUSTR: LUST database

Map ID Unique ID Facility Description Data Source

29

169 OHD982619322 Automotive Services US EPA Envirofacts - RCRIS

170 LUST257001900 Underground Storage Tank BUSTR: LUST database

171 OHD095019691 Commercial/Industrial US EPA Envirofacts - RCRIS

172 LUST254060300 Underground Storage Tank BUSTR: LUST database

173 OHD980679716 State Services US EPA Envirofacts - RCRIS

174 - 175 OHD045082542 Commercial/Industrial US EPA Envirofacts - RCRIS, SARA III

176 Commercial SARA III

177 LUST253086000 Underground Storage Tank BUSTR: LUST database

178 LUST252022300 Underground Storage Tank BUSTR: LUST database

179 LUST251148500 Underground Storage Tank BUSTR: LUST database

180 OHD987013257 Gas Station US EPA Envirofacts - RCRIS

181 OHD004282307 Commercial US EPA Envirofacts - RCRIS

182 OHD987007358 Automotive Services US EPA Envirofacts - RCRIS

183 OHD987019478 Automotive Services US EPA Envirofacts - RCRIS

184 LUST252293600 Underground Storage Tank BUSTR: LUST database

185 Print shops/Photo shops Field Survey

186 OHD987036126 Commercial US EPA Envirofacts - RCRIS

187 OH0000044768 Commercial US EPA Envirofacts - RCRIS

188 Auto repair shops/Body shops Field Survey

189 Vacant Lot Ohio EPA-DERR MSL GIS layer

190 LUST257024200 Underground Storage Tank BUSTR: LUST database

191 LUST257121300 Underground Storage Tank BUSTR: LUST database

192 Chemical drums/Storage Field Survey

193 Gas station Field Survey

194 Gas station Field Survey

195 OHD980792378 Commercial US EPA Envirofacts - TRIS

196 Material stockpiles Field Survey

197 LUST257123700 Underground Storage Tank BUSTR: LUST database

198 OHD065978702 Commercial/Industrial US EPA Envirofacts - RCRIS

199 LUST259107601 Underground Storage Tank BUSTR: LUST database

200 OHD057806614 Automotive Services US EPA Envirofacts - RCRIS AIRS/AFS

Map ID Unique ID Facility Description Data Source

30

201 Automotive Services Ohio EPA-DERR MSL GIS layer

202 Commercial/Industrial SARA III

203 Gas station Field Survey

204 LUST254165300 Underground Storage Tank BUSTR: LUST database

205, 206 OHD982623167 Petroleum Distribution/Storage US EPA Envirofacts/SARA III

207, 208 RIP0003 Chemicals Mfg/Storage -hazardous waste site with groundwater monitoring

OEPA RIPFLEX Database, Ohio EPA-DERR MSL GIS layer

209 LUST252031600 Underground Storage Tank BUSTR: LUST database

210 LUST025805000 Underground Storage Tank BUSTR: LUST database

211, 212 OHD000816751 Chemicals/Petroleum Mfg/StorageUnderground Storage Tank

US EPA Envirofacts - RCRA AIRS/AFSDOCKET, SARA III

213 LUST025905800 Underground Storage Tank BUSTR: LUST database

214 OHD017891482 Automotive Services US EPA Envirofacts - RCRIS

215 LAN0020 Inactive/Closed Landfill OEPA Landfill GIS Layer

216 OH0000622688 Commercial US EPA Envirofacts - RCRIS

217 Commercial SARA III

218 OHD051368595 Commercial US EPA Envirofacts - RCRIS SSTS

219 OHD061762241 Commercial US EPA Envirofacts - RCRIS AIRS/AFS DOCKET

220 Commercial SARA III

221 OHD075033993 RCRAInfo US EPA Envirofacts - RCRIS

222 Commercial/Industrial SARA III

223 OH0001363910 Commercial US EPA Envirofacts - RCRIS

224 LUST250152200 Underground Storage Tank BUSTR: LUST database

225 OHD000608679 Commercial US EPA Envirofacts - RCRIS AIRS/AFS

226 LUST252241300 Underground Storage Tank BUSTR: LUST database

227 LUST252250800 Underground Storage Tank BUSTR: LUST database

228, 229 OHD079436077 Commercial/Industrial US EPA Envirofacts - RCRIS AIRS/AFSDOCKET, SARA III

230 LUST258061800 Underground Storage Tank BUSTR: LUST database

231 OHD075037374 Chemicals/Petroleum Mfg/Storage US EPA Envirofacts - RCRIS AIRS/AFSDOCKET

232 Chemicals/Petroleum Mfg/Storage SARA III

Map ID Unique ID Facility Description Data Source

31

233 LUST253031800 Underground Storage Tank BUSTR: LUST database

234 Commercial/Industrial Ohio EPA-DERR MSL GIS layer

235 OHD987022779 Commercial US EPA Envirofacts - RCRIS

236 LUST252198700 Underground Storage Tank BUSTR: LUST database

237 OHD065988206 Commercial US EPA Envirofacts - RCRIS

238 - 247 Automotive Services SARA III

248 OHD075018895 Commercial US EPA Envirofacts - RCRIS

249 LUST256046000 Underground Storage Tank BUSTR: LUST database

250 000007552076 Commercial US EPA Envirofacts - RCRIS

251 OHD986967388 Commercial/Industrial US EPA Envirofacts - RCRIS

252 OHD982210890 Commercial/Industrial US EPA Envirofacts - RCRIS

253 OHD981960123 Commercial US EPA Envirofacts - RCRIS PADS

254 Commercial SARA III

255 OH0001859313 Commercial US EPA Envirofacts - RCRIS

256 LUST025968100 Underground Storage Tank BUSTR: LUST database

257 OHD986989358 Quarry US EPA Envirofacts - AIRS/AFS

258 LUST253134400 Underground Storage Tank BUSTR: LUST database

259 OHD000683607 Commercial US EPA Envirofacts - RCRIS

260 LUST254143600 Underground Storage Tank BUSTR: LUST database

261 Laboratory SARA III

262 OHD987047800 Commercial US EPA Envirofacts - RCRIS

263 LUST252322800 Underground Storage Tank BUSTR: LUST database

264 LUST252323100 Underground Storage Tank BUSTR: LUST database

265 Material stockpiles Field Survey

266 LUST251170700 Underground Storage Tank BUSTR: LUST database

267 000007485010 Commercial/Industrial US EPA Envirofacts - RCRIS

268 OHD037534526 Commercial/Industrial US EPA Envirofacts - RCRIS

269 LUST251066700 Underground Storage Tank BUSTR: LUST database

270 Landfill Ohio EPA-DERR MSL GIS layer

271 OH0001859438 Commercial US EPA Envirofacts - RCRIS

272 Commercial SARA III

Map ID Unique ID Facility Description Data Source

32

273 Commercial SARA III

274 OHD982631970 Commercial US EPA Envirofacts - RCRIS

275 OHD987016110 Commercial/Industrial US EPA Envirofacts - RCRIS

276 Commercial/Industrial SARA III

277 OHD987037868 Commercial/Industrial US EPA Envirofacts - RCRIS

278 000007370062 Quarry US EPA Envirofacts - NPDES

279 OHD089427561 Commercial/Industrial US EPA Envirofacts - RCRIS

280 OHD023637671 Commercial/Industrial US EPA Envirofacts - RCRIS

281 OHD041078106 Commercial/Industrial US EPA Envirofacts - TRIS RCRISAIRS/AFS

282 Commercial/Industrial SARA III

283 LUST251224300 Underground Storage Tank BUSTR: LUST database

284 OHD037534583 Commercial/Industrial US EPA Envirofacts - RCRIS

285 OH0000060186 Commercial/Industrial US EPA Envirofacts - RCRIS

286 Material stockpiles Field Survey

287 Commercial/Industrial SARA III

288 OHD041901646 Commercial US EPA Envirofacts - RCRIS

289 OHD981198724 Dry Cleaners US EPA Envirofacts - RCRIS

290 LUST251281901 Underground Storage Tank BUSTR: LUST database

291 Veterinary offices Field Survey

292 Fleet/Truck/Bus terminals Field Survey

293 LUST251265001 Underground Storage Tank BUSTR: LUST database

294 OHD056742117 Commercial/Industrial US EPA Envirofacts - TRIS RCRISAIRS/AFS

295 OHD981000094 Commercial US EPA Envirofacts - RCRIS

296 LUST252201600 Underground Storage Tank BUSTR: LUST database

297 City Services SARA III

298 LUST258147200 Underground Storage Tank BUSTR: LUST database

299 LUST025995500 Underground Storage Tank BUSTR: LUST database

300 OHD981778202 Commercial US EPA Envirofacts - RCRIS

301 LUST251112900 Underground Storage Tank BUSTR: LUST database

302 Commercial SARA III

Map ID Unique ID Facility Description Data Source

33

303 OHD986967545 Commercial US EPA Envirofacts - RCRIS

304 Commercial SARA III

305 Gas station Field Survey

306 LUST025946700 Underground Storage Tank BUSTR: LUST database

307 OHD987052636 Commercial US EPA Envirofacts - RCRIS

308 Commercial SARA III

309 OH0001859362 Commercial/Industrial US EPA Envirofacts - RCRIS

310 LUST259012100 Underground Storage Tank BUSTR: LUST database

311 OHD980990873 Commercial US EPA Envirofacts - RCRIS AIRS/AFS

312 OHD982642175 Commercial US EPA Envirofacts - TRIS RCRISAIRS/AFS

313 Commercial SARA III

314 Gas station Field Survey

315 OHD982623381 Dry Cleaners US EPA Envirofacts - RCRIS

316 LUST253258000 Underground Storage Tank BUSTR: LUST database

317 OHD987015930 Commercial US EPA Envirofacts - RCRIS

318 OHD981537996 Commercial/Industrial US EPA Envirofacts - RCRIS

319 OHD987020765 Commercial US EPA Envirofacts - RCRIS PADS

320 Commercial/Industrial SARA III

321 Car/Boat/Camper dealerships Field Survey

322 Commercial Ohio EPA-DERR MSL GIS layer

324 LUST252159002 Underground Storage Tank BUSTR: LUST database

325 OH0001363639 Automotive Services US EPA Envirofacts - RCRIS

326 OHD051368553 Commercial US EPA Envirofacts - RCRIS

327 LUST252159001 Underground Storage Tank BUSTR: LUST database

328 OHD131890469 Commercial/Industrial US EPA Envirofacts - RCRIS

329 OHD042312629 Commercial/Industrial US EPA Envirofacts - RCRIS

330 LUST257080500 Underground Storage Tank BUSTR: LUST database

331 OHD987020740 Dry Cleaners US EPA Envirofacts - RCRIS

332 OHD092164557 Commercial US EPA Envirofacts - RCRIS

333 Commercial/Industrial SARA III

334 Plastics/Synthetics producers Field Survey

Map ID Unique ID Facility Description Data Source

34

335 OHD986983492 Vacant Lot US EPA Envirofacts - TRIS

336 LUST253067000 Underground Storage Tank BUSTR: LUST database

337 OHD987034501 Commercial US EPA Envirofacts - RCRIS

338 LUST252307800 Underground Storage Tank BUSTR: LUST database

339 OHD044528933 Commercial US EPA Envirofacts - RCRIS

340 Commercial SARA III

341 Commercial/Industrial SARA III

342 OHD986989226 Commercial/Industrial US EPA Envirofacts - RCRIS AIRS/AFSDOCKET

343 OHD986970432 Commercial/Industrial US EPA Envirofacts - RCRIS

344 Commercial SARA III

345 LUST252008400 Underground Storage Tank BUSTR: LUST database

346 LUST255003600 Underground Storage Tank BUSTR: LUST database

347 OHD095031035 Commercial/Industrial US EPA Envirofacts - RCRIS DOCKET

348 OHD987044716 Commercial/Industrial US EPA Envirofacts - RCRIS

349 OHD051368520 Commercial US EPA Envirofacts - RCRIS

350 Commercial/Industrial SARA III

351 OHD099733842 Commercial US EPA Envirofacts - RCRIS

Table 4 - Potential Contaminant Source Inventory for theColumbus-Hap Cremean Drinking Water Source Protection Area[Map ID number corresponds to Figures 7 and 7A]

Map ID Unique ID Facility Description Data Source

1 Other Industrial Sources Field Survey

2 Gas Station. Field Survey

3 Auto Repair Shop Field Survey

4 Auto Repair Shop Field Survey

5 Landscaping Firm Field Survey

6 Municipal WastewaterTreatment Plant

Field Survey

7 Auto Repair Shop Field Survey

8 Cemetery Field Survey

9 Chemical Drum Storage Field Survey

Map ID Unique ID Facility Description Data Source

35

10 Auto Repair Shop Field Survey

11 Auto Repair Shop Field Survey

12 Gas Station. Field Survey

13 Chemical Drum Storage Field Survey

14 Other Industrial Sources Field Survey

15 Chemical Drum Storage Field Survey

16 Schools (bus areas/garages) Field Survey

17 Above Ground StorageTanks

Field Survey

18 Other Industrial Sources Field Survey

19 Auto Repair Shop Field Survey

20 Salt/Deicing Storage Piles Field Survey

21 Auto Repair Shop Field Survey

22 Cemetery Field Survey

23 Hardware / Parts Store Field Survey

24 Hardware / Parts Store Field Survey

25 Cemetery Field Survey

26 Other Industrial Sources Field Survey

27 Municipal WastewaterTreatment Plant

Field Survey

28 Gas Station. Field Survey

29 Gas Station Field Survey

30 Chemical Drums/ Storage Field Survey

31 Machine/metalworkingshops

Field Survey

32 Pesticide/fertilizer/petroleumstorage &

Field Survey

33 LUST021800800 Leaking Underground Tank BUSTR: LUST database (geocoded)

34 LUST210092100 Leaking Underground Tank BUSTR: LUST database (geocoded)

36 LUST216057000 Leaking Underground Tank BUSTR: LUST database (geocoded)

37 LUST217117400 Leaking Underground Tank BUSTR: LUST database (geocoded)

38 LUST218280100 Leaking Underground Tank BUSTR: LUST database (geocoded)

39 LUST025916000 Leaking Underground Tank BUSTR: LUST database (geocoded)

Map ID Unique ID Facility Description Data Source

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40 LUST253144500 Leaking Underground Tank BUSTR: LUST database (geocoded)

41 LUST253144501 Leaking Underground Tank BUSTR: LUST database (geocoded)

42 LUST255102000 Leaking Underground Tank BUSTR: LUST database (geocoded)

43 OHD004282885 Commercial US EPA Envirofacts - TRIS AIRS/AFS

44 OHD018091918 Dry Cleaners US EPA Envirofacts - RCRIS

45 OHD075035469 Commercial US EPA Envirofacts - RCRIS

46 OHD981198880 Dry Cleaners US EPA Envirofacts - RCRIS

47 OHD987009602 Automotive Services US EPA Envirofacts - RCRIS

48 LAN0040 Unknown Status Landfill OEPA Landfill GIS Layer

49 CEM0552 Cemetery USGS Geonames

50 CEM3523 Cemetery USGS Geonames

51 SIM0553 Oxidation OEPA-DSW Surface Impoundment GISLayer

52 SIM0592 Oxidation OEPA-DSW Surface Impoundment GISLayer

54 000007363916 Drinking Water TreatmentPlant

61 CEM2058 Cemetery USGS Geonames

62 AIR0042 Airport USGS Geonames

63 031006-JL01 Wastewater Treatment Plant Field Survey

64 031006-JL02 Wastewater Treatment Plant Field Survey

Data Source Explanation

AIRS Airborne Emissions (AIRS) Facilities report releases of pollutants into the air. Airborne pollutants can bedeposited in surface waters.

CERCLIS Facilities that have been identified as hazardous or potentially hazardous and may require action by U.S.EPA under Superfund. The sites are being (or have been) investigated for releases of hazardousmaterials. These types of facilities may be associated with soil, ground water, and surface watercontamination from releases of hazardous materials.

DOCKET Facilities that have been involved in an action filed by the U.S. Department of Justice for U.S. EPA. These actions may relate to one or more U.S. EPA program.

FFIS Treatment, storage, and disposal facilities owned and operated by Federal agencies. These types offacilities may be associated with potential releases of hazardous materials.

PADS Facilities that are authorized by U.S. EPA to use, store, transport, or dispose polychlorinated biphenyls(PCBs). These types of facilities may be associated with potential leaks and spills of PCBs or otherhazardous materials.

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PCS Facilities that hold a National Pollutant Discharge Elimination System (NPDES) permit. The NPDESpermit program controls water pollution by regulating point sources such as pipes or man-made ditchesthat discharge pollutants into waters of the United States.

RCRIS Facilities regulated by U.S. EPA under the Resource Conservation and Recovery Act (RCRA) ashazardous waste generators or handlers. These types of facilities may be associated with potentialreleases of hazardous materials.

SSTS Facilities that produce pesticide, active ingredients, and devices. These types of facilities may beassociated with potential releases of pesticides or other hazardous materials.

TRIS Toxics Release Inventory (TRI) facilities are industrial facilities that manufacture, process, or import anyof over 300 listed toxic chemicals that are released directly into the air, water, or land, or are transportedoff-site.

NPL Facilities listed on U.S. EPA’s National Priority List requiring cleanup of uncontrolled or hazardous waste,these facilities are a subset of the CERCLIS site list. These types of facilities may be associated withsoil, ground water, and surface water contamination from releases of hazardous materials.

MSL Sites that have been investigated by or are under investigation by Ohio EPA’s Division ofEmergency andRemedial Response. These types of facilities may be associated with soil, ground water, and surfacewater contamination from releases of hazardous materials.

LUST Facilities that have reported a leaking underground storage tank (LUSTs) to Ohio’s Bureau ofUnderground Storage Tank Regulations (BUSTR). Leaking underground storage tanks have beenassociated soil and water contamination related to leaks and spills of gasoline and other petroleumproducts. Unused underground storage tanks may be used for the improper disposal of wastes.

RIPFLEX Hazardous waste sites that have provided ground water monitoring information.

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Figure 1 - Source water areas (surface water) for the Columbus public water system.

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Figure 2 - Emergency Management Zone for the Dublin Road water intake.

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Figure 3 - Emergency Management Zone for the Hap Cremean water intake.

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Figure 4 - Land use in the Columbus-Dublin Road WTP source water area. (Based on1992 land use data)

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Figure 5 - Land use in the Columbus-Hap Cremean WTP source water area. (Basedon 1992 land use data)

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Figure 6 - Potential contaminant sources in the corridor management zone for theDublin Road water intake.

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Figure 6.1 - Symbols used in Figures 6A, 6B, and 6C for depicting types of potentialcontaminant sources.

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Figure 6A - Potential contaminant sources in the corridor management zone for theDublin Road water intake.

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Figure 6B - Potential contaminant sources in the corridor management zone for theDublin Road water intake.

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Figure 6C - Potential contaminant sources in the corridor management zone for theDublin Road water intake.

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Figure 7 - Potential contaminant sources in the corridor management zone for the HapCremean water intake.

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Figure 7A - Potential contaminant sources in the Sunbury and Galena vicinity.