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Response to Commissioner Scott's Comments

Berks County Commissioner Mark Scott’s provided several comments and questions regarding the Exide investigation and cleanup at the stakeholders meeting on October 10, 2007. Commissioner Scott also spoke at the Exide cleanup public meeting on October 11, 2007.  EPA has summarized Commissioner Scott’s comments and provides a response below. 

Many of Commissioner Scott’s comments concerned portions of the 1998 Remedial Investigation Report (RIR) provided by Exide to the Pennsylvania Department of Environmental Protection (PADEP).  This investigation report was the first attempt at characterizing the historical contamination emitted by the lead smelter.

 The United States Environmental Protection Agency (EPA) 2001 Administrative Order on Consent (Order) required Exide to expand the 1998 investigation report with additional characterization.   The results of the expanded investigation are available in the following series of documents:

2001 Step1 Environmental Sampling Work Plan
2001 Interim Remedial Measures Closure Report
2001 Step 2 Environmental and Human Health Sampling Work Plan
2001 Bernhart Park Work Plan
2001 Bernhart Park Results
2002 Interim Remedial Measures Closure Report
2003 Blood Lead Study and Environmental Sampling Report
2003 Child Lead Risk Assessment Report
2007 Residential Remediation Work Plan

Commissioner Scott expressed concern over the impact of past smelter emissions on groundwater in the area.

The 1998 Remedial Investigation Report referenced groundwater sampling of residential wells in the vicinity of the Exide facility.  Twenty-nine residences were sampled on multiple occasions. The process consisted of sampling at several locations (faucet, pressure tank, outdoor spigot) within the household plumbing network under various withdrawal scenarios (e.g., first draw water, extended use).  Out of the twenty-nine residences sampled, eleven residences detected lead levels above EPA drinking water standard of 15 parts per billion (ppb). 

Lead does not easily leach from soil and impact groundwater.  Several conditions (low pH, high temperature and high oxidation-reduction potential) must be present before lead mobility is a problem.  Lead much more readily adsorbs to soil particles and stays within the top layer of soil.

Up until the 1950’s, lead pipe was used as water supply line and in plumbing fixtures.  Lead was a component in solder used on copper pipes until the1980s.  The homes tested were built during this era.  In addition, testing of soil during the first phase of the cleanup showed that the lead was not leaching from the soil at appreciable levels.

Given these factors, EPA concluded that the source of the lead found during the Remedial Investigation is the result of the age of the plumbing infrastructure and the homeowners were so informed.

Commissioner Scott had several questions related to the size of the study area.
 
The Study Area referenced in the 1998 Remedial Investigation Report was more limited than the study required under the Order.  The map below illustrates the study area expansion in 2001 and 2002.  This larger study area encompasses a much larger area, including the Vo-Tech School, and is based on over 12,000 samples of individual properties.  EPA is confident that the present Study Area is representative of the extent of the lead contamination due to smelter emissions.

Figure 1 shows the difference between the 1998 Study Area and the present Study Area.
Figure 2 displays the results within the present Study Area.

 

Exide Map 1   

Figure 1: Delineation of the 1998 Study Area and the Present Study Area

 ______

Exide Map
Note: In 2004, EPA determined that the soil lead levels in the Saylor's Development are below 500 mg/kg and do not pose a health risk. Additional evaluation is not required.

Figure 2: Present Study Area 2007

Commissioner Scott asked several questions regarding the presence of additional metal contaminants, particularly Arsenic and Cadmium in area soils.

In 1997, PADEP directed Exide to sample soils in the vicinity of the Exide facility to determine the extent of the lead contamination.  As part of that effort, PADEP required Exide to collect co-located samples to evaluate arsenic and cadmium in soil.  The results from the discrete and co-located samples are listed in the table below.

Soil Heavy Metal Results

Sample
Lead
Arsenic
Cadmium
1
118
22.6
0.4
2
126
4.0
0.5
3
132
0.4
0.4
4
255
6.2
1.0
5
366
1.8
0.5
6
385
3.1
0.5
7
392
9.0
0.6
8
434
19.3
1.0
9
509
6.8
0.5
10
523
18.3
1.4
11
529
11.8
1.0
12
675
0.4
1.0
13
677
10.5
0.4
14
712
9.2
0.9
15
787
3.1
0.7
16
790
6.3
1.2
17
892
7.4
1.0
18
929
10
1.0
19
950
19.9
4.1
20
1223
38.9
3.2
21
1310
12
1.0
22
1320
7.6
1.1
23
1571
8.9
1.5
24
1746
9.8
1.8
25
1798
13.8
1.4
26
2067
26
1.6
27
2275
14.1
1.1
28
2330
7.4
0.5
29
2350
16.8
1.3
30
2436
7.6
1.8
31
2473
8.5
0.5
32
2920
4.4
0.5
33
2970
8.6
0.8
34
3550
23
4.5
35
3600
15.1
0.5
36
3853
25.1
4.2
37
5690
54
2.4
38
10708
58.9
5.8

Note: All values are in mg/kg.  Bold values exceed Pennsylvania’s arsenic level of 12 mg/kg for direct soil contact. 

Heavy Metal Analysis in Soil

These results show that cadmium levels never exceeded the PA Statewide health level of 47 mg/kg. 

There is a moderately strong statistical correlation that relates soil lead level to soil arsenic levels (R=0.75).  This means that we can expect the level of lead and arsenic in a given soil sample to be proportional.  Thus, EPA is confident that the lead cleanup level of 650 mg/kg will be protective for those few instances where arsenic may also be elevated above the typical EPA cleanup level of 20 mg/kg.  In the Exide study area, soils with arsenic levels above 20 mg/kg have already been remediated since these levels were associated with lead levels over 1200 mg/kg.

Out of the 38 samples, one sample detected a 118 mg/kg lead concentration with an arsenic level 22 mg/kg.  The sample is located outside the Exide study area.  The low soil lead value suggests that the arsenic is unlikely to be from smelter emission and more likely to be from other sources such as pressure treated lumber, fertilizers, or pesticides.

Additional soil samples collected during the 2007 and 2008 sampling events will also be analyzed for arsenic and cadmium.  EPA will evaluate the ratios of arsenic and cadmium to lead in soil and will post the results and its final determination at the conclusion of the sampling events

Commissioner Scott expressed concern that the smelter emission contamination of heavy metals could leach out of the soil matrix and move freely in the environment.

Toxicity Characteristic Leaching Procedure (TCLP) tests were conducted during the initial residential cleanups to determine if lead or other metals could leach from the area soils.  All of the testing occurred at properties that exhibited soil lead concentrations greater than 1200 mg/kg and as high as 7500 mg/kg.  The results of the TCLP tests characterized the soil as non-hazardous and confirmed that heavy metals do not substantially leach from the soil.  Below is the range of results of the TCLP tests for the constituents of concern and the allowable TCLP limits.

Toxicity Characteristic Leaching Procedure Results

 

Metal

TCLP Tests
(mg/L)

Maximum Concentration of Contaminants
for Toxicity Characteristic (mg/L)

Lead

<0.05 – 3.7

5

Arsenic

<0.05

5

Cadmium

<0.1

1

Chromium

<0.5

5

Selenium

<0.05

1

(Results from the 2001 and 2002 Interim Measures Remedial Closure Reports)

Region 3 The Mid-Atlantic States


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