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PUBLIC HEALTH ASSESSMENT

FIRST PIEDMONT ROCK QUARRY
BEAVER PARK, VIRGINIA


ENVIRONMENTAL CONTAMINATION AND OTHER HAZARDS

Contaminants and physical hazards on and in the vicinity of the FPRQ site will be discussed in this section. The contamination encountered in the quarry and immediately adjacent area will be addressed in the ON-SITE CONTAMINATION section. Refer to Figure 3 for the approximate area considered to be on-site and locations of the North Pond, South Pond, Waste Pile, Carbon Black, Old Disposal Area, Northern Drainage area, and Southern Drainage area. The contamination or potential for contamination beyond the FPRQ site will be addressed in the OFF-SITE CONTAMINATION section. The information will be presented according to environmental media (soil, water, air, etc.) in which contaminants were found.

The concentrations of the contaminants were determined from sampling analyses collectedduring the RI. The maximum concentration of a specific contaminant found in that investigationwill be shown in the tables presented in this section. The maximum concentration will then becompared to existing guidelines which are referred to as comparison values. When theconcentration of a contaminant of concern is greater than the corresponding comparison value, itwill be discussed in this section and further evaluated in other sections of this assessment.

Some contaminants have several different comparison values (depending on the environmental medium where the contaminant is found). Other contaminants may have no established comparison values. The comparison values which are presented in the tables are considered to be the most appropriate values for a specific medium. For instance, the value selected may consider that a child could be exposed to the contaminant in order to consider worse-case scenarios. The types of comparison values used for this evaluation are Environmental Media Evaluation Guides (EMEGs), Reference Dose Media Evaluation Guides (RMEGs), Cancer Risk Evaluation Guide (CREG), and EPA Action Levels (AL). As indicated, comparison values are defined in the Glossary of this document.

A. ON-SITE CONTAMINATION

The RI identified the hazardous substances on the site (Phase I), assessed the vertical andhorizontal extent to which these substances have dispersed (Phase II), and collected samplesfrom selected areas (Phase III). The media sampled during that investigation included waste pilesoil, surface soil, sediment, surface water, and groundwater. Air was not sampled during the RI.

Waste Pile Soil

The Waste Pile is located about 100 feet west of the quarry. It consists of shredded rubber and nylon cord and could not be sampled directly. Therefore, grab samples (3) of soil materials below the Waste Pile were collected during Phase II and a composite sample (composite of 10 samples) was collected during Phase III of the RI. The maximum contaminant concentrations found in soil samples collected from below the Waste Pile are shown in Table 1. This list, except for barium, contains only those contaminants found above the comparison values used. The comparison values shown in Table 1 are calculated for soil ingestion by a typical child (200 milligrams of soil per day).




Table 1.

Maximum Contaminant Concentrations in Soils Beneath the On-Site Waste Pile (13)
ContaminantConcentration
(mg/kg)1
Comparison Values2
Value(mg/kg)Source
Arsenic
543
20
RMEG
Barium
2,760
4,000
RMEG
Cadmium
16.8
10
EMEG
Lead
5,270
None
None

1mg/kg = milligrams/kilogram equivalent to parts per million
2The comparison value sources are defined in the Glossary

Surface Soils

Soil samples were collected from soils defined as "surface soils" from a grid pattern at 7 locations in the quarry area (13). These samples were collected at a depth of 6 to 12 inches. Because a 1 or 2-foot soil cover was placed over the waste material in 1980, VDH assumes that most of these samples are of the soils covering the waste material. VDH and ATSDR define surface soils as 0-3 inches deep because that is the soil portion people are most likely to contact. The samples analyzed from this study may not be representative of actual surface conditions; however, discussion in this section and subsequent evaluations in this public health assessment of contaminants of concern will assume the concentrations detected are representative of surface conditions because the cover soil should be fairly consistent. Leaching of any contamination to the surface should be identified at 6 to 12 inch depths.

The maximum contaminant concentrations found in the surface soil samples are presented in Table 2. The comparison values shown in Table 2 are calculated for soil ingestion by a typical child (200 milligrams of soil per day). These data appear to indicate that the soil cover on the waste contains some heavy metals, but at much lower levels than the contaminant concentrations of the actual waste. The concentrations detected may also be naturally occurring, depending on the source of the soil cover. None of the metals were above comparison values where values were available. No comparison value is available for lead; therefore, the contaminant is listed as a contaminant of concern.

Table 2.

Maximum Contaminant Concentrations in On-Site Surface Soil (13)
Concentration

(mg/kg)1

Comparison Values2
Value(mg/kg)Source
Lead
1,430*
None
None

1mg/kg = milligrams/kilogram equivalent to parts per million
2The comparison value sources are defined in the Glossary
*Source of this number is the Virginia Department of Waste Management, public comments, Appendix C

Sediments

Sediment samples were collected during the RI from the North Pond, a seepage (leachate) area on the western side of the quarry, and the upper portion of the Northern Drainage (sample FP-209). The maximum contaminant concentrations detected for these samples are presented in Table 3. The comparison values shown in Table 3 are calculated for soil ingestion by a typical child (200 milligrams of soil per day).

Table 3

Table 3.

Maximum Contaminant Concentrations in On-Site Sediments (13)
ContaminantConcentration

(mg/kg)1

Comparison Values2
Value(mg/kg)Source
Arsenic
72
20
RMEG
Barium
9,900
3,500
RMEG
Cadmium
34.5
10
EMEG
Lead
79.4
None
None

1mg/kg = milligrams/kilogram equivalent to parts per million
2The comparison value sources are defined in the Glossary

These results indicate that on-site sediments do have elevated contaminant concentrations. Thisis likely related to sediment contact with the surface water.

Surface Water

The layout of the rock quarry is similar to a large tilted bowl filled with waste. Water saturatesthe waste and flows out the lower lip of the bowl (Seepage Area). The Seepage Area, NorthPond, and upper Northern Drainage are all connected and have relatively continuous, but low,volume flow. Soil staining indicates, that during high flow periods, some surface water drainsfrom the seepage area southwestward to the Southern Drainage. The South Pond has no directsurface connection with the other major on-site surface water areas. The South Pond also doesnot have significantly elevated contaminant levels; therefore, it will not be further discussed inthis section.

Surface water samples were collected during the RI from the North Pond, a seepage (leachate) area on the western side of the quarry, and the upper portion of the Northern Drainage. The maximum contaminant concentrations detected in that set of samples are presented in Table 4. Comparison values, which are based on drinking water health criteria, are offered in Table 4; however, none of these surface water sources would likely be used as a drinking water source.

Table 4.

Maximum Contaminant Concentrations in On-Site Surface Water (13)
ContaminantConcentration (g/L)1
Seepage

Area

North PondUpper

Northern

Drainage

Comparison

Value

Source
Arsenic
23.1
58
13.7
0.02
CREG
Barium
6,170
8,420
5,600
700
RMEG
Cadmium
8.9Q
ND
ND
2
EMEG
Lead
10.7
21.1
4.1
15
AL

1g/L = micrograms/liter equivalent to parts per billion
2 Comparison values are calculated for a typical child's (10 kg) anticipated drinking water consumption (1 L/day)
Q = Questionable data (see Quality Control/Quality Assurance section)
ND = Not detected

The on-site surface water data indicate that the water surfacing in the seepage area has migratedthrough the landfill. The contaminants surfacing at the seepage area appear to concentrate in theNorth Pond. Contaminant concentrations in the Northern Drainage indicate a possibility that theNorth Pond runoff is likely diluted with uncontaminated water at some point upgradient to thesampling location in the Northern Drainage.

Groundwater

The RI included installation of 14 monitoring wells. Six of the monitoring well locations consist of a deep well ("B" wells) and a shallow well ("A" wells) at each location. The shallow wells tap the zone of relatively shallow groundwater in the saprolitic soils while the deep wells tap groundwater in the bedrock. Refer to Figure 4 for the locations of these monitoring wells.

The groundwater gradients indicate that the primary groundwater movement is to the northwestin both the shallow and deep groundwater zones. The shallow groundwater gradients mimic thelocal topography because groundwater surfaces (seepage) in the north and south drainage area. Deeper flow is not significantly affected by the drainage and flows in the direction of the generaldownward topographic gradient.

The on-site groundwater condition is considered to be characterized by 5 monitoring wells (FP-003A&B, FP-004B, and FP-007A&B), although no monitoring wells are within the landfillitself. FP-001A&B characterize the upgradient groundwater conditions. The remainingmonitoring wells are considered to be off-site for purposes of this assessment.

Maximum contaminant concentrations detected in both the shallow and deep monitoring wells are listed in Table 5. The results presented are for dissolved metals (samples were filtered). Unfiltered samples are preferable for water that is used as a drinking water source. The comparison values presented in Table 5 are calculated for drinking water consumption by a 10 kg child (1 liter per day).

Table 5.

Maximum Contaminant Concentrations in On-Site Groundwater (13)
Contaminant Dissolved Concentration

(g/L)1

Comparison Values2
Shallow Deep Value(g/L) Source
Arsenic <2 <2 0.02 CREG
Barium 161E 169E 700 RMEG
Cadmium <4.7 <4.7 2 EMEG
Manganese 4,600 200 50 RMEG

1g/L = micrograms/liter equivalent to parts per billion
2The comparison value sources are defined in the Glossary
E = Estimated value

The values shown in Table 5 indicate that the shallow and deep groundwater are affected by the landfill. The concentrations of manganese is elevated above upgradient concentrations. Zinc is also higher than upgradient concentrations, but it is not present at levels above comparison values. Other contaminant concentrations listed in Table 5 are near those values found in the upgradient monitoring well (FP-001A&B).

Manganese was not found in unusually high concentrations in other on-site media. The sourceof manganese is not known, but there are only limited data concerning the waste products fillingthe quarry. This assessment assumes there is a subsurface source within the quarry.

B. OFF-SITE CONTAMINATION

The off-site media sampled during the RI include sediment, surface water, and groundwater. Sediment and surface water samples were taken from the same location during 2 periods ofsampling (June and August 1989). Private wells in the Beaver Park community were sampledby EPA in 1988.

Sediment

Off-site sediment samples were collected during two separate sampling periods from the Northern Drainage, Southern Drainage, and Lawless Creek. The sample locations are shown on Figure 4.

The off-site sediments do not have significantly elevated (above background and comparisonvalues) contaminant concentrations. Lead concentrations in the Northern and Southern Drainage(16.1 mg/kg and 14.5 mg/kg, respectively) are considered relatively low. The most elevatedconcentrations are those of manganese (485 mg/kg) and zinc (713 mg/kg) in the SouthernDrainage.

Surface Water

Off-site surface water samples were collected at the same time as the sediment samples.Additional surface water sampling was done (January 1990) in the area of the Old Disposal Pileduring Phase III of the RI because of elevated metal results in previous tests. This additionalsampling was done after a rainfall event (1 inch), which can result in some dilution.

The maximum contaminant concentrations found in the Northern and Southern Drainage are presented in Table 6. No contaminant concentrations were found above comparison values in Lawless Creek. The comparison values presented in Table 6 are for drinking water consumed by a child. The creek is not used as a drinking water source, but the comparison value helps to determine where further evaluation of a contaminant is needed.

Table 6.

Maximum Contaminant Concentrations in Off-Site Surface Water (13)
ContaminantConcentration
(g/L)1
Comparison Values2
Northern

Drainage

Southern

Drainage

Value (g/L)Source
Arsenic<2<20.02CREG
Barium10942.1700RMEG
Cadmium<4.7105E32EMEG
Manganese75.13,03050RMEG
Zinc32.8111,0003,000RMEG

1g/L = micrograms/liter equivalent to parts per billion
2The comparison value sources are defined in the Glossary
3E = Questionable due to cadmium detected in the field blank.

Those results, together with supporting data, indicate that large contaminant concentrations arenot leaving the quarry through the Northern Drainage, but that the Southern Drainage surfacewater is contaminated. The source of this contamination is suspected to be the Carbon BlackPile.

The Southern Drainage has elevated cadmium (105g/L), manganese (3,030 g/L), and zinc (111,000 g/L) levels. These concentrations were detected at a sampling location in the vicinity of the Old Disposal Area (Figure 3, FP-306). Other sampling locations are about 150 feet (FP-307) and 400 feet (FP-308) down gradient from the Old Disposal Area. Table 7 shows the concentrations of cadmium, manganese, and zinc from the second round of sampling (August 1989) at the 3 separate sampling locations (upper, middle, and lower) in the Southern Drainage.

Table 7.

Maximum Concentrations of Selected Metals in Southern Drainage Surface Water(13)
ContaminantConcentration

(g/L)1

Comparison Values2
UpperMiddleLowerValue

(g/L)

Source
Cadmium
63.4
<4.7<4.7
2
EMEG
Manganese
2,780
127
80.8
50
RMEG
Zinc
67,600
2,720
2,040
3,000
RMEG

1g/L = micrograms/liter equivalent to parts per billion
2The comparison value sources are defined in the Glossary

These data appear to indicate that, although there is a significant influx of the metals listed in Table 7 in the upper portion of the Southern Drainage, their concentrations are greatly reduced prior to entering Lawless Creek.

The concentrations given in Tables 6 and 7 were determined during Phase II of the RI during a relatively low flow rate (less than 1 gallon per minute). Phase III of the RI included sampling of the Southern Drainage during a relatively high flow period (10 times the flow) after significant precipitation. The results of the Phase III RI indicate that as flow rates increase the contaminant concentrations decrease; therefore, the contaminant concentrations in the Southern Drainage and in Lawless Creek are dependent on the flow rates.

Lawless Creek was sampled at 3 locations (Figure 4) during two separate rounds of sampling. There are 1 upgradient sampling location (FP-312) and 2 down gradient sampling locations (FP-313 and 314). Table 8 presents the concentrations of metals detected above comparison values during second round of sampling (August 1989).

Table 8.

Concentrations of Selected Metals in Lawless Creek (13)
ContaminantConcentration

(g/L)1

Comparison Values2
FP-312FP-313FP-314Value (g/L)Source
Cadmium<4.7<4.7 <4.7 2EMEG
Manganese38.460.573.550RMEG

1g/L = micrograms/liter equivalent to parts per billion
2The comparison value sources are defined in the Glossary

The site does appear to impact Lawless Creek. This impact is manifested as an approximatetwo-fold increase in the manganese concentrations when compared to background values. Zincis also present above background levels, but zinc concentrations are below comparison values.

Groundwater

The off-site groundwater conditions are considered to be characterized by 7 monitoring wells (FP-002A, FP-005A&B, FP-006A&B and FP-008A&B). The locations of these wells are shown in Figure 4. Contaminant concentrations of dissolved metals detected in the shallow monitoring wells (FP-002A, FP-005A, FP-006A, and FP-008A) and the deep monitoring wells (FP-005B, FP-006B, and FP-008B) are presented in Tables 9 and 10, respectively. Total (unfiltered) metals levels are preferable when evaluating water that may be used as a drinking water supply. Filtered samples that provide information on dissolved metals are not representative of what people may actually drink if well water is not filtered. The comparison values presented in Tables 9 and 10 are calculated for drinking water consumption by a 10 kg child consuming 1 liter of water per day.

Table 9.

Dissolved Metal Concentrations in Shallow, Off-Site Groundwater (13)
ContaminantConcentration (g/L)1Comparison Values2
Monitoring Well No. FP-Value

(g/L)

Source
002A005A006A008A
Arsenic<2<2<2<2
0.02
CREG
Cadmium<4.7<4.7<4.7<4.7
2
EMEG
Manganese
26.9
41.5
28.3
1,260
50
RMEG

1g/L = micrograms/liter equivalent to parts per billion
2The comparison value sources are defined in the Glossary
3E = Estimated value

The shallow, off-site groundwater contaminant concentrations are not significantly above theconcentrations found in the upgradient well (FP-001A) with the exception of manganese andzinc in monitoring well FP-008A. Zinc is not present in downgradient monitoring wells at levelsabove comparison values. Well FP-008A is the only well down gradient from all the possiblecontamination source areas.

Table 10.

Dissolved Metal Concentrations in Deep, Off-Site Groundwater (13)
Contaminant Concentration (g/L)1Comparison Values2
Monitoring Well No. FP-
Value (g/L)Source
005B006B008B
Arsenic<2<2<2 0.02CREG
Cadmium<4.7 <4.7 <4.7 2EMEG
Manganese5.817042050RMEG

1g/L = micrograms/liter equivalent to parts per billion
2The comparison value sources are defined in the Glossary
3E = Estimated value

The deep, off-site groundwater also has manganese and zinc concentrations similar to theshallow, off-site groundwater, but of a lesser magnitude. Although zinc is present abovebackground levels, it is not present at levels above comparison values.

Private Wells

Ten private wells were sampled in late 1988. One well exhibited an elevated concentration ofiron (466 µg/L) and lead (16.2 µg/L). Another well had an elevated concentration of iron (333µg/L) and manganese (65.1 µg/L). Two of the contaminant levels, lead and iron, exceededEPA's Action Level or Secondary Maximum Contaminant Levels (SMCL). Lead has anAction Level of 15 µg/L, and iron has an SMCL of 300 µg/L. The wells exhibiting elevatedmetal concentrations are not the closest wells to the site that have been tested, and they arehydraulically upgradient from the site. Therefore, FPRQ is not likely the source of the metalsaffecting their water quality. (Old plumbing pipes are often sources of lead and ironcontamination in drinking water.)

Private wells were sampled again in October 1993. Elevated iron levels were detected in onewell, but no other contaminants that were tested were detected above comparison values.

Ambient Air

Ambient air was not sampled during the RI.

C. QUALITY ASSURANCE AND QUALITY CONTROL (QA/QC)

Contaminant concentrations cited in this public health assessment were derived from the RI Report. Difficulties, with respect to availability of site information, were encountered in the preparation of this public health assessment. The RI Report used for this assessment was originally issued February 12, 1990. That report was revised August 15, 1990, and that revision was incorporated into the February 12, 1990, copy of the RI Report. The Figures (1-9) and Appendices (A-N) were not included with the text of the RI Report. VDH understands that another revision dated January 28, 1991, was made to the RI Report and was not available within a time frame that could be used for this assessment.

The analytical data tables in the RI Report were presented with qualifiers. The data presentedare considered adequate with several shortcomings which were noted in the RI Report and takeninto consideration in preparing this assessment. A significant data gap is in the analytical resultsfor cadmium. The potential for concern of cadmium in groundwater is difficult to determinesince the lower detection limit of the analytical method was 4.7 g/L, while our comparisonvalue was 2 g/L. Also, cadmium was found in the field blank for round one surface water andsediment samples; therefore, only round two results could be used.

In preparing this document, VDH relied on the information provided in the referenceddocuments and assumed that adequate quality assurance and quality control measures werefollowed with regard to chain-of-custody, laboratory procedures, and data reporting. Thevalidity of the analysis and conclusions drawn for this public health assessment are determinedby the availability and reliability of the referenced information.

D. PHYSICAL AND OTHER HAZARDS

The physical hazards associated with the FPRQ are typical of those encountered in abandonedrock quarries. In the past, access to the site was impeded by some fencing but not completelyrestricted. The site is now fenced; therefore, access to the physical hazards is restricted.

E. Toxic Chemical Release Inventory (TRI)

To identify possible facilities that could contribute to the contamination near the FPRQ site,VDH searched the 1987, 1988, and 1989 records of the TRI for the zip code in which FPRQexists. TRI has been developed by EPA based on data from chemical release (air, water, soil)information provided by certain industries. Possibly due to the fact that this is a rural area withvery little industry, no record of any toxic release was found.


PATHWAYS ANALYSES

In order to determine past, present, or future human exposures to site-related contaminants,VDH and ATSDR have evaluated the environmental exposure pathways that lead to humanexposure. Environmental exposure pathways consist of the following five elements: 1) thesource of the contaminant; 2) its transport through an environmental medium (i.e., water, soil,air); 3) the physical location where a human is exposed (point of exposure); 4) an exposedpopulation; and 5) a route of exposure (such as ingestion, inhalation, or dermal contact).

An environmental pathway is either complete, potential, or eliminated, depending on thepresence of the five exposure pathway elements. In a completed exposure pathway, all fiveelements have been identified. Human exposure has occurred in the past, is occurring, or willoccur in the future. In a potential exposure pathway, one or more elements has not beenidentified with existing data, but a likelihood exists that the element may be present. Humanexposure may have occurred in the past, may be occurring, or may occur in the future. Aneliminated exposure pathway is, and always will be, missing one or more elements.

A. Completed Exposure Pathways

There are no existing data which indicate that humans have been, are being, or will be exposedto contaminants from the site. However, previous testing of private wells did detect elevatediron, manganese, or lead concentrations in two of the wells. The wells service residences;therefore, the estimated number of people exposed to the contaminants is 6 to 10. The elevatedconcentrations are not likely site related. Because people are using the contaminated well water,the pathway is considered complete, although the source of the contamination is unknown. Oldplumbing is often the cause of elevated iron and lead levels in drinking water.

B. Potential Exposure Pathways

The potential exposure pathways are dependent, in part, on a point of exposure for a receptorpopulation. Site access is now restricted. Access to off-site contaminated media is unrestricted,but the Northern and Southern Drainage areas are in densely vegetated areas and access to themis difficult. This assessment assumes that occasional past use (trespassing) occurred at the site,and people wonder onto adjacent areas occasionally.

A discussion of the potential pathways follows.

Surface Drainage

The upper portion of the Southern Drainage contains heavy metals at levels above comparison values (Table 6 and 7). This drainage is nearest the highway and is fed by a spring upgradient from the site. Dense vegetation hinders access, but occasional incidental ingestion of and dermal contact contaminants found in surface water in the drainage area by children playing in there is possible.

Groundwater

The only contaminant that exceeds comparison values in the shallow groundwater is manganese. No wells used by people have been identified downgradient of the site. However, should futuredevelopment of the area result in the drilling of new wells downgradient of the site, those wellscould be threatened. If that happened, people could be exposed to contaminants throughingestion and dermal contact.

C. Eliminated Exposure Pathways

The following exposure pathways are eliminated because the assumption is made that siteworkers will use appropriate precautions to prevent their exposures to contaminants. Also, theassumption is made that site access restriction is effective.

Waste Pile

The Waste Pile on site contains contaminant concentrations well above comparison values (Table 1). People are not expected to come into contact with the waste pile unprotected or for long periods of time. Therefore, no exposure is expected to occur at levels of concern.

Soil

Available data are for soil samples collected 6-12 inches below the surface. The existing datasummarized in Table 2 do not indicate that the contaminant concentrations are over comparisonvalues. Therefore, contact with the soil covering should not result in exposure.

Surface Water

On-site surface water has elevated contaminant concentrations (Table 4). The appearance of this surface water is similar to a leachate. Because of the aesthetically unappealing appearance of the water and the inaccessibility to it, people are not likely to come into contact with the water.

Air

Transport of contaminants through the air is insignificant because most of the landfill is coveredby natural soil materials and most compounds detected are non-volatile.

Biota

Game animals could ingest on-site surface water and off-site fish may be exposed to slightly elevated contaminant concentrations in Lawless Creek. Game animals are unlikely to ingest enough contaminated water to cause any accumulation in tissue that could harm people. The contaminant concentration in Lawless Creek are not elevated (Table 8), with the exception of manganese and zinc. These metals found on and off site are not likely to bioaccumulate at concentrations that would harm people should they ingest the animals.


PUBLIC HEALTH IMPLICATIONS

The Public Health Implications section is divided into three subsections. The first reviews the known, possible toxicological outcomes following exposure to certain site contaminants. The second subsection evaluates available state health outcome database information. The third subsection addresses specific community health concerns that were recorded in the Community Health Concerns section.

A. TOXICOLOGICAL EVALUATION

No site-related completed exposure pathways have been identified. People have been exposed toelevated levels of iron, manganese, and lead through use of their private wells. Thatcontamination is not likely site-related because the wells are upgradient of the site. Commonsources of that type of contamination are household plumbing and wells tapping water that isnaturally high in minerals. Iron, at high levels, is unpalatable. People would not likely drinkwater with levels of iron that may harm them. For that reason, iron is not evaluated further. Although not site-related, lead and manganese exposures will be evaluated in this section inorder to provide the community with information about the health implications of theirexposures.

ATSDR's Minimal Risk Levels (MRLs) and EPA's Reference Doses (RfDs) are used toevaluate any possible non-cancer health outcomes that may occur as a result of exposure. Cancer risk is calculated using EPA's Cancer Slope Factors (CSFs). When MRLs, RfDs, andCSFs are not available, other health-based values may be used to help with the evaluation of theexposures.

Lead

People were exposed to lead through use of their private well water at a maximum of 16.2 g/L (13). There is no MRL or RfD for lead, but the current EPA AL is 15 g/L for drinking water (a first draw sample) (5). The private well lead concentration is slightly above the EPA AL. However, lead was not detected above comparison values in private wells when sampled in October 1993.

The database for lead is unusual in that it contains a great deal of information about dose-response relationships in humans; however, data are normally expressed in terms of internal exposure (normally blood levels), rather than in terms of environmental exposure levels (5). An important data gap is that studies have not determined what environmental concentrations cause elevated blood levels after exposure (5).

Adults do not absorb lead readily through the digestive tract, whereas children absorb lead more readily. Most of the absorbed lead is stored in bones. Lead is also distributed to the red blood cells, blood plasma, kidney, liver, and brain. That storage is cumulative, and the body's lead levels increase over time with additional exposure (5). The amount of lead in the body is normally estimated by measuring blood levels. The lead in hair, bone, teeth, and urine can also be determined (5).

The end points of greatest concern for human health are the blood, the nervous system, heart and blood vessel systems, vitamin D metabolism, and growth (11). Much of the available information about lead exposure in humans was determined by blood lead levels; some studies did not use modern protocols. Therefore, animal data must be relied upon to determine the potential effects from exposure to lead through the consumption of drinking water containing lead (5).

Laboratory studies in a variety of animals revealed that exposure to lead in drinking water caused responses that were related to the lead dose. The primary effect was a depression of the immune system. Other effects included developmental delays (as seen in delays in righting reflexes) and decreases in the blood hemoglobin levels of the fetus (5). An EPA review of animal studies concluded that low-level lead exposure before or soon after birth results in retarded growth; however, this review did not establish dose-effect relationships. Other studies in rats and mice have provided no evidence that oral exposure to lead causes birth defects (5).

Segments of the population at highest risk from health effects from lead exposure are preschool-age children, pregnant women and their fetuses, and white males between 40 and 59 years of age (5). Lead in a pregnant woman can be carried to the unborn child and cause premature birth and low birth weight. In infants and young children, lead exposure has been shown to decrease intelligence (IQ) scores, slow growth, and cause hearing problems. Those effects can happen at low exposure levels and last as the children get older (5). Exposure to lead in children occasionally produces progressive mental deterioration. The history of exposed children (blood lead levels 30-50 µg/dL) indicates normal development during the first 12-18 months of life, or longer, followed by a steady loss of motor skills and speech. They may have severe hyperkinetic and aggressive behavior disorders and a poorly controlled convulsive disorder. The lack of sensory perception severely impairs learning ability (9). Long-term exposure resulting in blood lead levels between 15-30 g/dL can result in increase blood pressure in middle-aged males (5).

Lead interacts with many elements and nutrients. Calcium, iron, and phosphorus inhibit lead absorption. Inadequate levels of iron enhances the effects of exposure to lead on certain blood and liver enzyme activities (5).

Lead is classified by EPA as a Class B carcinogen. This means it is a probable human carcinogen, based on inadequate evidence of carcinogenicity in humans and sufficient evidence of carcinogenicity in experimental animals. No CSF has been developed for lead to help evaluate the cancer risk for the exposed people (5).

Manganese

People have been exposed to manganese through use of their private well water at a maximum of 65.1 g/L. That level exceeds the comparison value (RMEG for a child) and the EPA SMCL of 50 g/L for manganese in drinking water (6). The SMCL is set for aesthetic quality and is not health-related. Manganese was not detected in private wells at levels above comparison values in October 1993.

If an adult ingests one liter of water containing 65.1 g/L of manganese a day, the average daily dose would not exceed the RfD. Therefore, no non-cancerous adverse health effects are expected to occur for adults. Although the RfD is slightly exceeded for children ingesting that level, the average daily dose received is far below that obtained from ingesting 2,500-5,000 g/day, which is the normal intake from a healthy diet (6). Therefore, no non-cancer adverse health effects are expected for children.

EPA has determined that manganese is not classifiable as to human carcinogenicity (6). There is little evidence to suggest that cancer is a major concern for people exposed to manganese in the environment or near waste sites (6).

B. HEALTH OUTCOME DATA EVALUATION

There have been no documented health outcome data collected. Therefore, health outcome dataanalyses cannot be performed at this time.

C. COMMUNITY HEALTH CONCERNS EVALUATION

The community members around FPRQ are concerned about their current and future drinkingwater quality. Because of the earlier actions of the local health department, residents are relyingon local government to effectively deal with the problem. In a meeting on April 16, 1991, withstaff from the Virginia Department of Waste Management, the Pittsylvania CountyAdministrator identified two environmental groups that may be interested in the site (SouthsideConcerned Citizens and Pittsylvania Environmental Awareness). A public meeting held on thatsame date to discuss the proposed option for remediation attracted approximately 50 people fromthe surrounding area.

Many issues other than health concerns were raised; however, the question asked mostfrequently was "How do we know that contaminated groundwater is not flowing into privatewells?" The answer to this question has two parts: all residential wells are upgradient from thesite, and studies support the finding that groundwater at the site is flowing away from the nearbyhouses. Although some metals that were found on the site were also found in two private wells,those metals are naturally occurring and are often found in tap water. If the plumbing in thehome is old, especially if the pipes are galvanized with lead solder, iron and lead levels can behigh. The most recent sampling of the private wells indicate that no contaminants that weretested are present at levels of health concern.

The community concern about future groundwater safety is increasing, and the community has requested a public water line be supplied. The groundwater contamination at the site is not flowing toward private wells in the area. However, the concern about groundwater safety is understandable. Because of the concern, ATSDR and VDH recommend periodic sampling of the wells, which EPA has provided. The most recent sampling was conducted in October 1993. Of the constituents tested, only iron was found in one well above comparison values. The elevated levels of iron are likely from naturally occurring iron mix with iron from household plumbing. EPA must determine whether or not a public water line is to be supplied. With the information ATSDR and VDH has to date, an alternate water supply is not indicated at this time. People who periodically have elevated iron, lead, or manganese in their water may want to consider adding a filtration system to the household water system or, at least, to the kitchen tap. Also, people with galvanized plumbing and lead solder may want to consider updating their plumbing if that is financially feasible. One way to decrease lead levels at a tap is to allow the water to run for two or three minutes before using the water. That flushes out the lead that has accumulated in the line. Also, do not use hot tap water for drinking or cooking. The hot water lines tend to accumulate a little more lead (if lead solder is present in lines).


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