COVER SHEET

Name of Site: St. Clair Shores Drain

EPA ID No.: MIN000510063

Contact Person
United States Environmental Protection Agency (EPA), Region V
Patrick Hamblin 77 West Jackson Boulevard, Mail Code: SR-6J Chicago, Illinois 60604 (312) 886-6312
Site Investigation: Joseph Walczak Michigan Department of Environmental Quality (517) 373-4951
Pathways, Components, or Threats Not Scored
The ground water migration, ground water to surface water migration, soil exposure and air migration pathways are not scored as part of this Hazard Ranking System (HRS) evaluation. The ground water, ground water to surface water, soil exposure, and ai r migration pathways were not included because a release to these media does not significantly affect the overall site score and because the surface water migration pathway produces an overall site score above the minimum required for the site to qualify for inclusion on the National Priorities List (NPL).
Ground Water Migration Pathway: There are insufficient data to document the HRS requirements for establishing the threat of release via ground water at the St. Clair Shores Drain Site.
Soil Exposure Pathway: While there could be potential for contact with contaminated media, the evaluation of this pathway does not affect the listing decision.
Air Migration Pathway: The majority of surficial and sha llow PCB contaminated soil has been removed and the majority of the PCB contamination is located over 2 feet below ground surface, in the storm sewer system, or below water in canal and lake sediments. Therefore, the air pathway at the St. Clair Shores Drain Site was not scored.HRS DOCUMENTATION RECORD

Name of Site: St. Clair Shores Drain Date Prepared: March 2010
EPA Region: V

Street Address*: Intersection of Bon Brae Street and Harper Avenue
City, County, State, Zip Code: St. Clair Shores, Macomb County, Michigan, 48081 (Figure 1) (Refs. 3; 4)

General Location in State: Southeast Michigan
Topographic Map: 7.5-Minute Series Topographic Map: Grosse Pointe Quadrangle, Michigan, 1968 (Photorevised 1983) (Ref. 3).

Latitude: 42o 29’ 13” North (Refs. 3; 4, pp. 1, 2)
Longitude: 82o 53’ 57” West (Refs. 3; 4, pp. 1, 2)
The latitude and longitude listed above mark the lo cation of the Intersection of Bon Brae Street and Harper Avenue (Ref. 4, pp. 1, 2; Figure 1 of this HRS documentation record).

*The street address, coordinates, and contaminant locations presented in this HRS documentation record identify the general area where the site is located. They represent one or more locations EPA considers to be part of the site based on the screening information EPA used to evaluate the site for NPL listing. EPA lists national priorities among the known “releases or th reatened releases” of hazardous substances; thus, the focus is on the release, not delineated boundaries. A site is defined as where a hazardous substance has been “deposited, stored, placed, or otherwise come to be located.” Generally, HRS scoring and the subsequent listing of a release merely represent the initia l determination that a certain area may need to be addressed under the Comprehensive Environmenta l Response, Compensation, and Liability Act (CERCLA). Accordingly, EPA contemplates that th e preliminary description of site boundaries at the time of scoring will be refined as more information is developed regarding wher e the contamination has
come to be located.

Scores
Ground Water Migration Pathway 0.00 Surface Water Migration Pathway 97.76 Soil Exposure Pathway 0.00
Air Pathway 0.00
HRS SITE SCORE 48.88

1WORKSHEET FOR COMPUTING HRS SITE SCORE

S S 2 1. Ground Water Migration Pathway Score (S gw ) (from Table 3-1, line 13) NS
2a. Surface Water Overland/Flood Migration Component (from Table 4-1, line 30) 97.76 9557.0176
2b Ground Water to Surface Water Migration Component (from Table 4-25, line 28) NS
2c. Surface Water Migration Pathway Score (S sw ) (enter the larger of lines 2a and 2b as the pathway score) NS 9557.0176
3. Soil Exposure Pathway Score (S s ) (from Table 5-1, line 22) NS NS
4. Air Migration Pathway Score (S a ) (from Table 6-1, line 12) NS NS

5. Total of S gw 2 + S sw 2 + S s 2 + S a 2 9557.0176

6. HRS Site Score 48.88 Divide the value on line 5 by 4 and take the square root.

Note: NS -- Not Scored

23 SURFACE WATER OVERLAND FLOW/FLOOD MIGRATION COMPONENT SCORESHEET

Factor Categories and Factors

DRINKING WATER THREAT Maximum Value Assigned Value

Likelihood of Release 1. Observed Release 2. Potential to Release by Overland Flow: 2a. Containment 2b. Runoff 2c. Distance to Surface Water 2d. Potential to Release by Overland Flow (lines 2a[2b + 2c]) 3. Potential to Release by Flood: 3a. Containment (Flood) 3b. Flood Frequency 3c. Potential to Release by Flood (lines 3a x 3b) 4. Potential to Release (lines 2d + 3c, subject to a maximum of 500) 5. Likelihood of Release (higher of lines 1 and 4) 550

10 25 25 500

10 50 500 500 550 550

NS

550

Waste Characteristics 6. Toxicity/Persistence 7. Hazardous Waste Quantity 8. Waste Characteristics * * 100 10,000 100 32 Targets 9. Nearest Intake 10. Population 10a. Level I Concentrations 10b. Level II Concentrations 10c. Potential Contamination 10d. Population (lines 10a+10b+10c) 11. Resources 12. Targets (lines 9 + 10d + 11) 50

**   **  5 ** 1

0 0 2 2 5 8

13. DRINKING WATER THREAT SCORE 100 1.70
Notes: * -- Maximum value applies to waste characteristics category ** -- Maximum value not applicable NS -- Not Scored4 SURFACE WATER OVERLAND FLOW/FLOOD MIGRATION COMPONENT SCORESHEET

Factor Categories and Factors

HUMAN FOOD CHAIN THREAT Maximum Value Assigned Value

Likelihood of Release 14. Likelihood of Release (same as line 5) 550 550
Waste Characteristics 15. Toxicity/Persistence/Bioaccumulation 16. Hazardous Waste Quantity 17. Waste Characteristics * * 1000 5 x 10 8
100 320 Targets 18. Food Chain Individual 19. Population 19a. Level I Concentrations 19b. Level II Concentrations 19c. Potential Contamination 19d. Population (lines 19a+19b+19c) 20. Targets (lines 18 + 19d) 50 **   **  ** ** 45

0 0.03

0 0.03 45.03 21. HUMAN FOOD CHAIN THREAT SCORE 100 96.06

Notes: * -- Maximum value applies to waste characteristics category ** -- Maximum value not applicable5 SURFACE WATER OVERLAND FLOW/FLOOD MIGRATION COMPONENT SCORESHEET

Factor Categories and Factors

ENVIRONMENTAL THREAT Maximum Value Assigned Value

Likelihood of Release

2. Likelihood of Release (same as line 5) 550 NS
Waste Characteristics

23. Ecosystem Toxicity/Persistence/Bioaccumulation 24. Hazardous Waste Quantity 25. Waste Characteristics * * 1000 NS NS NS Targets

26. Sensitive Environments 26a. Level I Concentrations 26b. Level II Concentrations 26c. Potential Contamination 26d. Sensitive Environments (lines 26a+26b+26c) 27. Targets **   **  ** NS NS NS NS

NS 28. ENVIRONMENTAL THREAT SCORE 60 NS

29. WATERSHED SCORE 100 97.76

30. SURFACE WATER OVERLAND FLOW/FLOOD COMPONENT SCORE 100 97.76 Notes: * -- Maximum value applies to waste characteristics category ** -- Maximum value not applicable NS -- Not Scored10 REFERENCES

1. U. S. Environmental Protection Agency (EPA). Hazard Ranking System Final Rule. Title 40 of the Code of Federal Regulations (CFR), Part 300, Appendix A. 139 Pages.
http://www.epa.gov/superfund/sites/npl/hrsres/rule/part1_2.pdf http://www.epa.gov/superfund/sites/npl/hrsres/rule/part3a.pdf http://www.epa.gov/superfund/sites/npl/hrsres/rule/part3b.pdf http://www.epa.gov/superfund/sites/npl/hrsres/rule/part3c.pdf http://www.epa.gov/superfund/sites/npl/hrsres/rule/part4a.pdf http://www.epa.gov/superfund/sites/npl/hrsres/rule/part4b.pdf http://www.epa.gov/superfund/sites/npl/hrsres/rule/part5.pdf http://www.epa.gov/superfund/sites/npl/hrsres/rule/toc_sec1.pdf http://www.epa.gov/superfund/sites/npl/hrsres/rule/sec2.pdf http://www.epa.gov/superfund/sites/npl/hrsres/rule/sec3.pdf http://www.epa.gov/superfund/sites/npl/hrsres/rule/sec4a.pdf http://www.epa.gov/superfund/sites/npl/hrsres/rule/sec4b.pdf http://www.epa.gov/superfund/sites/npl/hrsres/rule/sec4c.pdf http://www.epa.gov/superfund/sites/npl/hrsres/rule/sec4d.pdf http://www.epa.gov/superfund/sites/npl/hrsres/rule/sec5.pdf http://www.epa.gov/superfund/sites/npl/hrsres/rule/sec6.pdf http://www.epa.gov/superfund/sites/npl/hrsres/rule/sec7.pdf

2. EPA. Superfund Chemical Data Matrix (SCDM), SC DM Data Versions: January 2004. Excerpt. 1 page. A complete copy of SCDM can be found at:
http://www.epa.gov/superfund/sites/npl/hrsres/tools/scdm.htm

3. U.S. Geological Survey (USGS). 7.5-Minute Seri es Topographic Map: Grosse Pointe Quadrangle, Michigan, 1968 (Photorevised 1983). 1 Page.

4. Weston Solutions, Inc. (WESTON). Longitude and Latitude Determination. August 31, 2009. 2 Pages.

5. State of Michigan, Department of Environmental Quality (MDEQ). Site Inspection Report, St. Clair Shores Drain. December 3, 2009. 387 Pages.

6. EPA, Site Assessment Report, Ten Mile Drain Polych lorinated Biphenyl Investigation Site, St. Clair Shores, Macomb County, Michigan, Volume I of II. Prepared by Tetra Tech EM Inc., July 31, 2002. 249 Pages.

7. U.S. Department of Health and Human Services. Ten Mile Lange/Revere Drainage System, Petitioned Health Consultation, December 20, 2002. 60 Pages.

8. WESTON. April-May 2005 Site Investigation Report and Focused Feasibility Study, Volume I of II, St. Clair Shores Drain Site. October 2005. 194 Pages.
8A. MDEQ, Work Plan/Safety Plan, 10 Mile Drain Area, Macomb County, Michigan. April 6, 2005. 19 Pages.
8B. WESTON. April-May 2005 Site Investigation Re port and Focused Feasibility Study, Analytical Results, Volume II of II, St. Clair Shores Drain Site. October 2005. 873 Pages.11 8C. Weston Solutions Inc., Work Plan, For Source Ar ea Investigation Activities at the Ten Mile Drain Site, Macomb County, Michigan, May 2005. 60 Pages.

9. MDEQ. Analytical Results, Laboratory Work Or der # 50400038, Report Date, April 22, 2005. 12 Pages.

10. MDEQ. Analytical Results, Laboratory Work Or der # 50400036, Report Date, April 14, 2005. 14 Pages.

11. MDEQ. Analytical Results, Laboratory Work Or der # 50400037, Report Date, April 22, 2005. 12 Pages.

12. MDEQ. Analytical Results, Laboratory Work Or der # 50400039, Report Date, April 22, 2005. 11 Pages.

13. MDEQ. Analytical Results, Laboratory Work Or der # 50400050, Report Date, April 27, 2005. 9 Pages.

14. EPA. Pollution Report, St, Clair Shores Drain, June 13, 2006. 4 Pages.

15. WESTON. Removal Report, St. Clair Shores PCB Site, April 2007. 9 Pages.

16. WESTON. 15-Mile Target Distance Lim it Map. August 28, 2009. 1 Page.

17. EPA. Contract Required Quantitati on Limits for SOM01.2. 1 Page.
17A. MDEQ. Surface Water/Sediment Sampling Da ta Sheets, July 28-30, 2008. 30 Pages.

18. WESTON. Record of Telephone Conversation between Gary White, Macomb County Health Department, and Lauren Cook, WESTON. September 8, 2009. 1 Page.

19. St. Clair River and Lake St. Clair Comprehensive Ma nagement Plan. June 2004. Excerpt, 22 Pages.
Available in its entirety at http://www.glc.org/stclair/.

20. U.S. Department of Health and Human Services. Health Consultation, St. Clair Shores PCBs – Residential Soils. November 27, 2007. 23 Pages.

21. Michigan Department of Community Health. 2002. Michigan Family Fish Consumption Guide. 25 Pages.

22. Michigan Department of Community Health. 2009. Michigan Family Fish Consumption Guide. 32 Pages.

23. Great Lakes Fishery Commission. Draft Fish Commun ity Goal and Objectives for Lake St. Clair, St. Clair River and Detroit River, March 28, 2003. 44 Pages.

24. Lake St. Clair: Its Current State and Future Pr ospects. Conference Summary Report, November 30- December 1, 1999. 70 Pages.

25. WESTON. Record of Telephone Conversation between Chuck Bellmore, Mount Clemens Water Department, and Lauren Cook, WESTON. November 24, 2009. 1 Page.

26. Reference reserved.12 27. WESTON. Record of Telephone Conversation between Antoine Pogue, Highland Park Water Department, and Lauren Cook, WESTON. November 24, 2009. 1 Page.

28. Reference reserved.

29. WESTON. Record of Telephone Conversation betw een Scott Homminga, Gross Pointe Farms Water Department, and Lauren Cook, WESTON. September 8, 2009. 1 Page.

30. WESTON. Population Calculation for City of Detr oit Water Intake, Omprakash Patel, December 1, 2009. 3 Pages.

31. WESTON. Record of Telephone Conversation betw een Ron Hayes, Detroit Water Department, and Lauren Cook, WESTON. December 2, 2009. 2 Pages.

32. MDEQ, Laboratory Services Section, Quality Assu rance Program Plan, May 5, 2003. 192 Pages.

33. Great Lakes Information Network (GLIN), Lake St. Clair. http:/www.greatlakes.net/lakes/stclair.html. Accessed November 20, 2009. 3 Pages.

34. MDEQ, Interoffice Communication, Fish Consumpti on Documentation for Lake St. Clair, Joseph Walczak, October 20, 2009. 1 Page.13 1.0 SITE DESCRIPTION
The St. Clair Shores Drain (SCSD) comprises an enclosed concrete storm sewer system surrounded by sand and gravel fill materials placed in native clay soils. The SCSD is located in a mixed residential/commercial area in St. Clair Shores, Macomb County, Michigan, near the western shore of Lake St. Clair (Refs. 5, p. 5; 6, p. 9). The SCSD storm sewer system drains approximatel y 0.5 square mile of the city of St. Clair Shores and terminates in an outfall on the Lange Street Canal (Ref. 8, p. 9). The Lange Street Canal then branches into two parallel canals, the Lange Street Canal and the Revere Street Canal, both of which drain into Lake St. Clair. The two canals are bordered by residences along thr ee streets (Ref. 6, p. 12). Figure 1 is site location

map.

In 2001, the county collected sediment samples from the Lange Street Canals in order to secure a dredging permit (Ref. 7, p. 9). Analytical results revealed polyc hlorinated biphenyls (PCBs) at concentrations up to 150 parts per million (ppm) in the canal sediments (Ref. 7, pp. 9, 37). As a result, the Michigan Department of Environmental Quality (MDEQ) and the Macomb County Public Works Office (MCPWO) initiated an investigation of the SCSD in February 2002 (Ref. 8, p. 10). PCBs were detected at a number of locations within the SCSD concrete piping, with the highest c oncentration being found at the intersection of Harper Avenue and Bon Brae Avenue (Ref. 8, p. 11).

Subsequently, EPA and MCPO conducte d sediment removal and dewatering ac tivities within a combined total of 5.5 miles of SCSD concrete piping (Ref. 8, p.11). However, monitoring efforts in 2003 and 2004 revealed the renewed presence of PCB-contaminated sediment and water within the SCSD drainage system (Ref. 8, p.11). EPA, MDEQ, MCPWO, and the city of St. Clair Shores have coordinated efforts to identify potential source areas and investigate potential migration pathways into or out of the SCSD. These investigations resulted in the discovery of PCBs located in the soils adj acent to the drain in several areas and in surficial soils in the area of Bon Brae and Harper Avenues (Ref. 8, pp.11, 12, Figs. 2 and 3). Figure 2 is an MDEQ soil boring location map, and Figure 3 is an MDEQ/EPA soil boring location map.

In 2006, EPA excavated surficial PCB-contaminated soils from several residential properties which were identified during the previous investigations, and installed an impermeable liner in the storm drain in the vicinity of Harper and Bon Brae Avenues, as a tempor ary measure to prevent PCBs from continuing to enter the drain (Ref. 5, p. 9). EPA also injected slurry into the soils of the utility corridor near the terminus of the liner to prevent PCBs from migrating through the soils in this vicinity (Ref. 5, p. 9).

It was subsequently determined that the site should be evaluated through the CERCLA site assessment process (Ref. 5, p. 6). MDEQ completed a Preliminary Assessme nt in June 2008, completed a Site Inspection (SI) Work Plan on July 3, 2009, and conducted SI field work July 28-30, 2008 (Ref. 5, p. 6). The scope of the SI included surface water and sediment sampling of the canals that currently receive drainage from the SCSD, as14 well as surface water and sediment sampling of Lake St. Clair and two canals that historically received drainage from an open drain in the vicinity of the SCSD (Ref. 5, pp. 6, 7, 16, Fig. 4). Findings of the SI revealed PCB contamination at varying levels in all of the water bodies sampled (Ref. 5, pp. 6, 7, 16). Figure 4 is a sediment sample location map corresponding to the SI sampling event. Lake Saint Clair and associated canals are used for recreation and fishing (Ref. 5, p.19).

Several sediment samples have ex ceeded TSCA Subpart D Cleanup Standa rds of 1,000 μg/kg; U. S. EPA Region 5 RCRA Ecological Screening Levels for sedimen ts (59.8 μg/kg); MDEQ Part 201 Residential and Commercial I Direct Contact Criteria of 4,000 μg/kg; and several other recommended guidance limits and effect levels (Ref. 5, p. 59),

The site, as currently scored for HRS purposes, includes the contamination within the SCSD concrete sewer pipes and contaminated subsurface soil surrounding th e SCSD concrete pipe. The contaminated soil surrounding the SCSD pipes was documented through soil samp ling at various depths near the intersection of Harper and Bon Brae Avenues. In addition, there is an observed release of PCBs to the sediments of Lange and Revere Street Canals, as well as to Lake St. Clair.15 2.2 SOURCE CHARACTERIZATION

2.2.1 Source Identification

Number of the source : 1
Name and description of the source : Contamination in the SCSD sewer pipes and subsurface contaminated soil surrounding the SCSD sewer pipes.
Source Type: Other -- Source type "other" was chosen becau se the contamination in the SCSD sewer pipes and subsurface contaminated soil surrounding the pipes fit no other HRS category.

Source 1 consists of PCB contaminat ion in the SCSD storm sewer pipes which are connected to the drain discharging into the Lange Street and Revere Street can als and leaking to/from the subsurface contaminated soil surrounding the pipes. In 2001, MCPWO collected sediment samples from the Lange Street canals to support its efforts to secure a dredging permit (Ref. 7, p. 9) . The analytical data results indicate the presence of PCBs at concentrations up to 150 ppm in canal sediment samples (Ref. 7, pp. 9, 37). As a result, MDEQ and MCPWO initiated an investigation of the SCSD utility co rridor in February 2002. The highest concentration of PCBs (3,270 ppm) was detected in sediment samples collected within the SCSD concrete piping at the intersection of Harper Avenue and Bon Brae Street (Ref. 8, p.11). EPA initiated sediment removal and dewatering activities in 2002 in the areas of the SCSD c oncrete piping exhibiting the highest levels of PCB
contamination. EPA vacuumed a nd power jetted approximately 1.25 miles of SCSD concrete piping from Lakeland Boulevard to Bon Brae Street and from Harper Av enue to the SCSD outlet at the Lange Street canals (Ref. 8, p.11). MCPWO conducted sediment remova l and dewatering activities along 4.25 miles of the remaining 5.75 miles of the SCSD concrete piping in the project area and installed steel plates near the SCSD outlet structure to trap and prevent additional discharge of PCB-contaminated sediments into the canal (Ref. 8, p.11).

Monitoring efforts in 2003 and 2004 revealed the renewe d presence of PCB-contamin ated sediment and water within the SCSD drainage system (Ref. 8, p. 11). EPA, MDEQ, MCPWO, and the City of St. Clair Shores have coordinated efforts to identify potential source areas and investigate potential migration pathways into or out of the SCSD utility corridor. In April 2005, direct- push soil borings were advan ced at 13 locations within the SCSD utility corridor along Bon Brae Street, Lakeland B oulevard, and Harper Avenue (Ref. 8, pp. 11, 12). The highest PCB concentration detected was 100 ppm at a depth of 8 to 8.5 feet below ground surface (bgs) (Ref. 8, p. 19). In May 2005, 64 additional direct -push soil borings were advanced at suspected source locations within the SCSD utility corridor along Bon Brae Street and Harper Avenue (Ref. 8. p. 12). The highest PCB concentration detected was 31,820 ppm at a depth of 0 to 1 feet bgs (Ref. 8, p. 19).

In 2006, EPA excavated surficial PCB-contaminated so il from several residential properties identified during previous investigations (Ref. 5, p. 8). The contamin ated areas were excavated to 8 to 12 inches bgs and then16 sampled for PCBs (Refs. 14, p. 3; 15, p. 6). If PCB contamination exceeding the site-specific cleanup goal (4 ppm) remained, then additional excavation to 2 feet bgs was conducted. Confirmatory soil samples were collected after excavation (Refs. 14, p. 3; 15, p. 6). These areas were backfilled, compacted and seeded to eliminate any direct contact threat to residents (R efs. 14, p. 3; 15, p.6). Following removal of PCB contaminated soil to a depth of 2 feet, PCB contaminated soil still remained at a depth greater than 2 feet bgs at some locations (see section 2.2.2 of this HRS documen tation record). The PCB-contaminated surficial soil (approximately 2-feet bgs) that was excavated from reside ntial properties in 2006 is not considered as part of
this source area.

Based on the information presented above, it is thought th at the PCBs were allegedly released in the SCSD concrete sewer pipes area near Bon Brae Street and Harp er Avenue by an unknown entity. The PCBs were then transported through the SCSD concrete sewer pipes that discharge into the Lange/Revere Street Canals through an outfall. The subsurface soil contamination in the vicinity of SCSD concrete sewer pipes is most likely caused by leaky sewer pipes.

Location of the source, with re ference to a map of the site: The contamination in the SCSD concrete sewer pipes that are connected to the drain discharging into th e Lange Street Canal and Re vere Street Canal and the contaminated soil surrounding the pipes are considered to be the source. The source area location is shown on Figure 1.

Containment: Releases to surface water through overland mi gration and/or flood: Th is source consists of contamination in the SCSD sewer pipes and contaminated soil surrounding the SCSD sewer pipes. The Lange Street and Revere Street canals, and Lake St. Clair have been contaminated with PCBs detected in the source area, therefore, there is evidence of hazardous s ubstance migration from the source. A surface water containment factor value of 10 was assigned (Ref. 1, Table 4-2, pp. 51609, 51610).

2.2.2 Hazardous Substances
Contamination in the Piping

The presence of PCBs has been documented into the SCSD sewer system that drains to the southeast and discharges to the canals (Refs. 6, p. 33; 8, p.11; 15, p. 2). A February 2002 MDEQ/MCPWO study (Ref. 8, p. 10) and a March 2002 START study (Ref. 6, pp. 32, 33) re vealed high levels of PCBs in the sediment in the SCSD piping. The highest concentration of PCBs (3, 270 ppm) was detected within the SCSD concrete piping at the intersection of Harper Avenue and Bon Brae Avenue (Ref. 8, p.10).

During March 2002 the USEPA Emergenc y Response Branch launched effort s in support of the MDEQ and
MCPWO to characterize the nature and extent of P CB contamination in the SCSD utility corridor and theLange Street Canals (Ref. 8, p.10). Laboratory anal ytical results from sediment samples collected by USEPA in the SCSD concrete piping indicated the presence of PCBs at a maximum concentration of 121,000 ppm at manhole location M4335 near the intersection of Bon Brae Avenue and E Street (Ref. 8, pp. 10, 11).

While EPA and the County conducted substantial removal and cleaning activities within the piping, as shown by the results of the MDEQ SI, PCB impacts from the cont amination in the piping remain in the sediments of the Lange and Revere Street canals. The removal di d not address the substances that already had escaped the piping prior to the removal, therefore, PCBs are associated with this portion of Source 1.

Contamination in the Subsurface Soil

Analytical results indicate that PCBs were present in 133 soil samples collected from 76 direct-push soil boring locations installed during April a nd May 2005 (Ref. 8, p. 19). On April 4 and 5, 2005, direct-push soil borings were advanced by MDEQ at 13 locations next to the SCSD utility corridor along Bon Brae Street, Lakeland Boulevard, and Harper Avenue. (Ref. 8, p. 11) . The work was performed by MDEQ in accordance with the work plan (Ref. 8A, p. 1). In May 2005, 64 additional direct-push soil borings were advanced at suspected source locations next to the SCSD utility corri dor along Bon Brae Street and Harper Avenue (Ref. 8, p.12). The work was performed by Weston Solutions of Michigan for MDEQ in accordance with the work plan (Refs. 8, p. 13; 8C).

Background Level: In order to characterize the soil portion of Source 1 through chemical analysis, soil samples collected from soil borings MSB-5 and MSB- 6 are considered to represent background contaminant levels (Ref. 8, p. 45). Soil boring MSB-5 is located in the northeastern portion of the contaminated soil area (Ref. 8, p. 45). Although this sample location is in the area of PCB contamination, this sample location was selected as a background sample because the primary contaminants of concern (PCB) were not detected in soil samples collected from this location. Soil boring MSB-6 is located at the northern border of the contaminated soil area (Ref. 8, p. 45). This location appears to be outsi de the influence of soil contamination (Ref. 8, p. 45). The soil boring location was selected because the primary contaminants of concern (PCBs) were not detected in soil samples collected from this location. The soil samples were collected from MSB-5 and MSB-6 at similar depths to the contaminated samples.

Although the HRS does not require that contamination meet observed release criteria to be associated with the source, EPA considers that contamination levels that meet the observed release criteria are sufficient to be
associated with the source.

17- Background Levels at Source 1 – Contaminated soil from unknown source
Three background soil samples were collected from soil boring MSB-6 from depths ranging from 0.5 to 1, 8.5 to 9, and 15 to 16 feet bgs (Ref. 8, pp. 107). Fi ve background soil samples were collected from soil boring MSB-5 from depths ranging from 0.5 to 1, 3 to 4, 7 to 8, 11 to 11.5 and 15 to 16 feet bgs (Ref. 8, pp. 106)
TABLE 1 BACKGROUND SOIL SAMPLES PCB (AROCLOR) CONCENTRATIONS

Sampling Location Type and USCS Description Depth (ft bgs) Date Hazardous Substance(s) RL (μg/kg) Concentration (μg/kg) References

Soil; CL 0.5 -1 4/5/2005 Aroclor-1248 110.0 ND Refs. 8, pp. 62, 106; 10, pp. 1, 2;8A, p.1

MSB-5 Soil; CL 3 -4 4/5/2005 Aroclor-1248 110.0 ND Refs. 8, pp. 62, 106; 10, pp.1, 3;8A, p.1 Soil; CL 7 - 8 4/5/2005 Aroclor-1248 120.0 ND Refs. 8, pp. 62, 106; 9, pp. 1, 6;8A, p.1 Soil; CL 11 ­ 11.5 4/5/2005 Aroclor-1248 110.0 ND Refs. 8, pp. 62, 106; 13, pp. 1,6 Soil; CL 15 - 16 4/5/2005 Aroclor-1248 120.0 ND Refs. 8, pp. 62, 106; 9, pp. 1, 7;8A, p.1 MSB-6 Soil; SP 0.5 -1 4/5/2005 Aroclor-1248 130.0 ND Refs. 8, pp. 62, 63, 107; 9, p. 8;8A, p.1 Soil; SW, CL 8.5 -9 4/5/2005 Aroclor-1248 120.0 ND Refs. 8, pp. 62, 63, 107; 9, p. 9;8A, p.1 Soil; CL 15 - 16 4/5/2005 Aroclor-1248 120.0 ND Refs. 8, pp. 62, 63, 107; 9, p. 10;8A, p.1

Notes: μg/kg – Microgram per kilogram Aroclor-1248 - one PCB congener bgs – Below ground surface CL – Clay ft – Feet ND – Non-detect PCB – Polychlorinated biphenyl RL – Reporting limit is at or above the MDL and is based on a calibration standard at or below the RL. RL is determined based on the calculated MDL using the speci fic reference method, the MDL spiking concentration, or a concentration based on these factors and B est Professional Judgment (Ref. 32, pp. 15, 16). MDL – Method Detection Limit SP – Poorly graded sand SW – Well-graded, fine to coarse sand USCS – Unified Soil Classification System

1819 - Source 1 – Contamination in the SCSD concrete sewe r pipes and subsurface contaminated soil surrounding the pipe area
It is thought that the PCBs were released in the SCSD sewer pipes area near Bon Brae Street and Harper Avenue by an unknown entity. The PCBs were then transported through the SCSD sewer pipes that discharge into the Lange Street Canal through an outfall. The s ubsurface soil contamination in the vicinity of SCSD concrete sewer pipes is most likely caused by leaky sew er pipes. The excavated PCB contaminated surficial soil (approximately 2-feet bgs) from residential properties in 2006 is not considered as part of this source area.

During the April 2005 soil boring investigation, PCBs were detected in 21 soil samples collected from 12 direct-push locations (Ref. 8, p. 19). The MDEQ Environmental Laboratory analyzed the samples using Method 8082 (Ref. 9, pp. 1-12; Ref. 10, pp. 1-14; Ref. 11, pp. 1-12; Ref. 12, pp. 1 -11; Ref. 13, pp. 1- 9). During the May 2005 soil boring investigation, PCBs we re detected in 112 soil samples collected from 64 direct-push soil boring locations (Ref. 8, p. 19). Envirosystems Laboratory and the MDEQ Environmental Laboratory analyzed the samples for PCBs (Ref. 8, pp. 13, 14). Envirosystems Laboratory analyzed the samples using CLP SOW OLM04.3, Modification Refe rence Number 1238.0, Title R5051605 (Ref. 8B, pp. 6, 30-34, 130, 212, 280, 510, 580, 622, 686).

In 2006, EPA excavated surficial PCB-contaminated soil from several residential properties identified during previous investigations (Ref. 5, p. 8). The contaminat ed areas were excavated to 8 to 12 inches bgs and then sampled for PCBs (Refs. 14, p. 3; 15, p. 6). If PCB contamination exceeding the site-specific cleanup goal (4 ppm) remained, then additional excavation to 2 feet bgs was conducted. Confirmatory soil samples were collected after excavation (Refs. 14, p. 3; 15, p. 6). These areas were backfilled, compacted and seeded to eliminate any direct contact threat to residents (Refs. 14, p. 3; 15, p.6); therefore, soil represented by the samples collected from 0 to 2 feet bgs and subseque ntly removed during the 2006 removal action are not included as part of the source area.20 TABLE 2 CONTAMINATED SOIL SAMPLES PCB (AROCLOR) CONCENTRATIONS

Sampling Location Type and USCS Description Depth (ft bgs) Date Hazardous Substance RL/SQL (μg/kg) Hazardous Substance Concentration (μg/kg) References

MSB-1 Soil; SW 8-9 4/4/2005 11,000 100,000 D JD Refs. 11, pp. 1, 3, 12; 8, p. 102; 8A, p.1; 8B, p. 837

MSB-2 Soil; SW 8-8.5 4/4/2005 120 320 JA JD Ref. 11, pp. 1, 6, 12; 8, p. 103 ;8A, p.1; 8B, p. 837

MSB-3 Soil; CL, SW 12-13 4/4/2005 120 160 JD Refs. 11, pp. 1, 11, 12;8, p. 104;8A, p.1; 8B, p. 837

MSB-7 Soil; CL 4-4.5 4/5/2005 2,300 19,000 D Refs. 10, pp. 1, 4, 14; 8, p.108;8A, p.1; 8B, p. 835

3.5-3.8 4/5/2005 1,100 5,000 D Refs. 10, pp. 1, 5, 14; 8, p.110; 8A, p.1; 8B, p. 835 MSB-9 Soil; S, CL

3.8-4 4/5/2005 120 310 JD JA Refs. 10, pp. 1, 6, 14; 8, p.110;8A, p.1; 8B, p. 835

3-4 4/5/2005 2,400 24,000 D JA Refs. 10, pp. 1, 9, 14; 8, p.111;8A, p.1; 8B, p. 835 MSB-10 Soil; CL

4-4.5 4/5/2005 2,700 13,000 D JA Refs. 10, pp. 1, 10, 14; 8, p.111;8A, p.1; 8B, p. 835

5-5.5 4/5/2005 6,000 27,000 D, JD Refs. 10, pp. 1, 12, 14; 8, p.113;8A, p.1; 8B, p. 836 MSB-12 Soil; CL

8-8.5 4/5/2005 6,100 52,000 D JD Refs. 10, pp. 1, 13, 14; 8, p.113;8A, p.1; 8B, p. 836

10-10.5 4/5/2005 110 180 JD Refs. 12, pp. 1, 4, 11; 8, p.111;8A, p.1; 8B, p. 839 MSB-10 Soil; CL

13-13.5 4/5/2005 Aroclor1248

640 3,100 D JA Refs. 12, pp. 1, 5, 11; 8, p.111;8A, p.1; 8B, p. 83921 Sampling Location Type and USCS Description Depth (ft bgs) Date Hazardous Substance RL/SQL (μg/kg) Hazardous Substance Concentration (μg/kg) References

SCS-001/ E0O39DL SC 4.5-9 5/17/05 200 2,100 DL Refs. 8B, pp. 5- 10, 15, 23, 62, 74-77; 8, p.137;8C, 18, 24- 31

SCS-001/ E0O40DL CL 9-12 5/17/05 85,000 990,000 DL Refs. 8B, pp. 5- 10, 16, 23, 64, 74-77;8, p.137;8C, 18, 24- 31

SCS-002/

E0O51 SC 6-9 5/17/09 37 450 Refs. 8B, pp. 509-514, 515, 525, 541, 570- 574; 8, p.138;8C, 18, 24-31

SCS-003/

E0O56 SC 9-12 5/17/09 39 76 Refs. 8B, pp. 509-514, 517, 525, 552, 570- 574; 8, p.139;8C, 18, 24-31

SCS-005/ E0O29DL SP 6-9 5/17/09 450 4,000 DL Refs. 8B, pp. 5- 10, 12, 21, 47, 74-77; 8, p.141;8C, 18, 24- 31

SCS-005/ E0O30DL SP 9-12 5/17/09 200 2,400 DL Refs. 8B, pp. 5- 10, 13, 21, 49, 74-77; 8, p.141;8C, 18, 24- 31

SCS-005/ E0O28DL SP 12-15 5/17/09 400 2,800 DL Refs. 8B, pp. 5- 10, 12, 21, 45, 74-77; 8, p.141;8C, 18, 24- 31

SCS-006/

E0O62 CL 9-12 5/17/09 34 47 Refs. 8B, pp. 509-514, 519, 527, 559, 570- 574; 8, p.142;8C, 18, 24-31

SCS-007/

E0O66 CL 6-9 5/18/09 Aroclor1248

34 95 Refs. 8B, pp. 509-514, 520, 527, 566, 570- 574; 8, p.143;8C, 18, 24-3122 Sampling Location Type and USCS Description Depth (ft bgs) Date Hazardous Substance RL/SQL (μg/kg) Hazardous Substance Concentration (μg/kg) References

SCS-014/

E0O79 SP/CL 11.5-13 5/18/09 39 120 Refs. 8B, pp. 5- 10, 17, 25, 69, 74-77; 8, p.150;8C, 18, 24- 31

SCS-023/ E0OC1DL SP 9-12 5/19/09 3,900 22,000 DL Refs. 8B, pp. 211-216, 221, 229, 267, 272- 274; 8, p. 159;8C, 18, 24- 31

SCS-024/ E0OC4DL CL 9-12 5/19/09 370 3,700 DL Refs. 8B, pp. 579-585, 586, 595, 608, 609, 611; 8, p.160;8C, 18, 24-31

SCS-025/ E0OC9DL SP 4-6 5/20/09 350 3,800 DL Refs. 8B, pp. 129-134, 137, 162, 190, 196- 198; 8, p. 161;8C, 18, 24- 31

SCS-025/ E0OD0D L SP 6-9 5/20/09 770 6,800 DL Refs. 8B, pp. 129-134, 137, 162, 192, 196- 198; 8, p. 161;8C, 18, 24- 31

SCS-025/ E0OC6DL SP 12-15 5/20/09 38,000 110,000 DL Refs. 8B, pp. 129-134, 136, 162, 184, 196- 198; 8, p. 161;8C, 18, 24- 31

SCS-025/ E0OC7DL CL 15-16 5/20/09 210,000 1,500,000 DL Refs. 8B, pp. 129-134, 136, 162, 186, 196- 198; 8, p. 161;8C, 18, 24- 31

SCS-026/

E0OD3 SP 5-6 5/20/09 Aroclor1248

35 530 Refs. 8B, pp. 579-585, 587, 596, 608, 609, 616; 8, p.162;8C, 18, 24-3123 Sampling Location Type and USCS Description Depth (ft bgs) Date Hazardous Substance RL/SQL (μg/kg) Hazardous Substance Concentration (μg/kg) References

SCS-026/ E0OD4D L SP 7.5-9 5/20/09 100 950 DL Refs. 8B, pp. 129-134, 138, 162, 195, 196- 198; 8, p. 162;8C, 18, 24- 31

SCS-027/

E0OG4 CL 12-15 5/24/09 38 193 Refs. 8B, pp. 630, 621-628, 639, 659, 678- 681; 8, p. 163;8C, 18, 24- 31

SCS-035/

E0O85 CL 4-5 5/18/09 41 78 Refs. 8B, pp. 296, 334, 346- 349, 278-284; 8, p.120;8C, 18, 24- 31

SCS-040/

E0OD8 SP 9-9.5 5/19/09 39 110 Refs. 8B, pp. 302, 318-321, 579-585, 588, 597; 8, p. 125;8C, 18, 24- 31

SCS-041/ E0OD9D L SP/CL 4-8 5/20/09 410 3,300 DL Refs. 8B, pp. 304, 318-321, 579-585, 588, 597; 8, p. 126;8C, 18, 24- 31

SCS-061/ E0OG3D L CL 9-12 5/24/09 7,800 31,000 DL Refs. 8B, pp. 630, 621-628, 638, 658, 678- 681; 8, p. 167;8C, 18, 24- 31

SCS-063/ E0OG9D L CL 12-15 5/24/09 390 3,200 DL Refs. 8B, pp. 631, 621-628, 638, 666, 678- 681; 8, p. 169;8C, 18, 24- 31

SCS-078/ E0OL0DL CL 6-9 5/25/09 Aroclor1248

830 6,500 DL Refs. 8B, pp. 684-692, 700, 708, 757; 8, p. 183;8C, 18, 24- 3124 Sampling Location Type and USCS Description Depth (ft bgs) Date Hazardous Substance RL/SQL (μg/kg) Hazardous Substance Concentration (μg/kg) References

SCS-078/ E0OL1DL CL 9-12 5/25/09 200 2,400 DL Refs. 8B, pp. 684-692, 701, 708, 761; 8, p. 183;8C, 18, 24- 31

SCS-078/ E0OK8D L SP 12-15 5/25/09 Aroclor1248

800 6,300 DL Refs. 8B, pp. 684-692, 699, 708, 754; 8, p. 183;8C, 18, 24- 31 Notes: μg/kg – Microgram per kilogram bgs – Below ground surface CL – Clay D – Analyte value quantified from dilution(s); reporting limit raised ft – Feet JA – Result considered estimated because multiple Aroclors present JD – Because of severe degradation, specific Aroc lor identification difficult and quantitation estimated PCB – Polychlorinated biphenyl RL – Reporting limit is at or above the MDL and is based on a calibration standard at or below the RL. RL is determined based on the calculated MDL using the speci fic reference method, the MDL spiking concentration, or a concentration based on these factors and Best Professional Judgment (Ref. 32, pp. 15, 16). RL is applicable to samples analyzed by MDEQ laboratory (April 2005 borings). MDL – Method Detection Limit S – Sand SC – Clayey sands, sand-silt mixtures SP– Poorly graded sand SQL – Sample Quantitation Limit, the SQL was derive d from the non-detected Aroc lors from the respective samples. SQL is applicable to the samples analyzed by CLP laboratory (May 2005 borings). SW– Well-graded, fine to coarse sand USCS – Unified Soil Classification System
The qualified data (JA and JD) are useable for source ch aracterization, because while the identification of the exact Aroclor mix or the specific PCB congener may ha ve been difficult in the qualified samples (based on type of J qualifier), these factors do not raise any ques tion regarding presence of the PCBs in the samples.

The MDEQ background and source soil samples collected in April 2005 were similar because the samples: (1) were most likely collected using the same equipment and procedures by the same individuals (Appendix A of Reference 8, pp. 102-114); (2) were collected within th e same time frame (4th April 2005 and 5th April 2005) and therefore, the same weather conditions (Ref. 8, pp. 59-66); (3) were analyzed using the same methods as documented in References 9 through 13; and (4) were co llected from similar soil types and similar depths as
documented in Tables 1 and 2 of this documentation record.25 The WESTON source soil samples collected in May 2005 were similar because the samples: (1) were collected using similar procedures (Ref. 8, p. 13, Appendix A); (2 ) were collected within the same time frame (May 17- 25, 2005) (Ref. 8, p. 12); and (3) were collected from similar soil types and similar depths as documented in
Tables 1 and 2 of this documentation record.

HAZARDOUS WASTE QUANTITY

2.4.2.1 Source Hazardous Waste Quantity

2.4.2.1.1 Hazardous Constituent Quantity (Tier A)
The information available is not sufficient to adequately determine Tier A as required in Section 2.4.2.1.1 of the HRS. As a result, the evaluation of the source h azardous waste quantity proceeds to the evaluation of Tier B, hazardous waste stream quantity (Ref. 1, Section 2.4.2.1.1, pp. 51590-51591).

2.4.2.1.2 Hazardous Wastestream Quantity (Tier B)
The information available is not sufficient to adequately determine Tier B as required in Section 2.4.2.1.2 of the HRS. As a result, the evaluation of the source h azardous waste quantity proceeds to the evaluation of Tier C, volume (Ref. 1, Section 2.4.2.1.2, p. 51591).

2.4.2.1.3 Volume (Tier C)
Since the hazardous waste quantity was not adequately determined under Tier A or B, the volume will be evaluated under Tier C. For the migration pathways, the source is assigned a value for volume using the appropriate Tier equation from Table 2-5 (Ref. 1, Sec tion 2.4.2.1.3). The equation for source type “other” is V/2.5, where V is expressed in cubic yards. It is not known how much PCB-containing material was originally spilled or discharged into the SCSD storm sewer system, nor is it known how much PCBcontaminated soil surrounds the piping. Despite the rem oval action, some quantity is present in the piping and in the surrounding soil, and some quantity has reached th e Lange and Revere Street Canals. For Source 1, a value of greater than zero but an amount unknown w as assigned for the hazardous waste quantity value for volume (Tier C). (Ref. 1, Section 2.4.2.1.3, Table 2-6, p. 51591).

2.4.2.1.4 Area (Tier D)
Area, Tier D, is not applicable for source type “other” (Ref. 1, Table 2-5).

2.4.2.1.5 Calculation of Source Hazardous Waste Quantity Value
As described in the HRS rule, the highest value assigned to a source from among the four tiers of hazardous waste quantity – constituent quantity (Tier A), wastestream quantity (Tier B), volume (Tier C), or area (Tier D)26 – shall be selected as the source hazardous waste quantit y value (Ref. 1, Table 2-6, p. 51591). As summarized in Table 3 below, Source 1 has a source hazardous wast e quantity value of greater than zero. Table 4 below summarizes the source description.

TABLE 3 SOURCE 1-- HAZARDOUS WASTE QUANTITY VALUE

Tier Measure Source Value Tier A, Hazardous Constituent Quantity Not Evaluated Tier B, Hazardous Wastestream Quantity Not Evaluated Tier C, Volume >0 Tier D, Area 0 Notes:
> -- greater than

TABLE 4 SUMMARY OF SOURCE DESCRIPTION
Containment Factor Value by Pathway SW Air Source

No. Source Hazardous Waste Quantity

Value Source Hazardous Constituent

Quantity Complete

(Y/N) GW (Table

3-2) Overland/Flood (Table 4-2) GW to SW (Table 3-2) Gas (Table 6-3) Particulate (Table 6-9)

1 >0 N NS 10 NS NS NS

Notes:
> -- greater than GW – Ground water HRS – Hazard Ranking System NS – Not scored SW – Surface water

The Source Hazardous Waste Quantity Value for the SCSD Site therefore is greater than 0.27 4.0 SURFACE WATER MIGRATION PATHWAY
The surface water pathway includes the overland flow and flood migration component and the ground waterto-surface water component. The overland flow and flood migration component has been evaluated as part of
this HRS documentation record.

4.1 OVERLAND AND FLOOD MIGRATION COMPONENT
This section describes the overland and flood migra tion component of the surface water pathway.

4.1.1.1 Definition of Hazardous Substance Migration Path for Overland/Flood Migration
The presence of PCBs has been documented in the SCSD sewer system that drains to the southeast and discharges to the Lange and Revere Street canals (Refs. 6, p. 33; 8, p. 11; 15, p. 2). The canals are connected to Lake St. Clair (Ref. 16). The probable point of entry (PPE) to surface water is the point where the SCSD sewer system discharges into the canal s. This is the beginning of the in-water segment of the surface water migration pathway (Ref. 16). PCB contamination is present in the source area at the site (see section 2.2.2 of this HRS documentation record). PCB contamination also is present in the Lange Street and Revere Street canals (Ref.5, p. 6). PCB contamination was detected in samples collected from the Lange Street and Revere Street canals, and Lake St. Clair (Ref. 5, p. 6). The hazardous substance migration path consists of the Lange and Revere Street canals, Lake St. Clair, and the Detroit River in-water segment (Ref. 16).

4.1.1.2 Target Distance Limit
The 15-mile target distance limit (TDL) begins at the SCSD outfall where the drain discharges into the canals, which in turn discharge to Lake St. Clair; the TDL continues along the Detroit River. The TDL is documented
in Reference 16.

4.1.2 Drinking Water Threat

4.1.2.1 Likelihood of Release
Numerous investigations have been conducted to determine the extent of contamination. Historical information and analytical data from the recent inves tigations are used to document an observed release to surface water through chemical analysis.

4.1.2.1.1 Observed Release

Direct Observation : An observed release through direct observation to the surface water migration pathway has not been
established at the site.28 Chemical Analysis : An observed release to the surface water pathway has b een established at the SCSD Site through chemical analysis. The observed release is based on the detection of PCBs in sediment samples collected from the canals and Lake St. Clair. In July 2008, 44 sedimen t samples, including 1 upgradient background sample and 4 duplicate samples, 2 equipment blank sa mples, and 2 field blank samples, were collected (Ref. 5, pp. 13, 14). Sediment samples were collected from 0 to 33 inches belo w the sediment-water interface (Ref. 5, pp. 31-40). The samples were analyzed for PCBs by CompuChem- Liberty Analytical Corporation in accordance with the Contract Laboratory Program (CLP) Statement of Wo rk (SOW) SOM01.2 (8/2007) (Ref. 5, pp. 15, 76, 145, 253). If the background concentration is not detected (or is less than the detection limit), an observed release is established when the sample measurement equals or exceeds the sample quantitation limit. (Ref. 1, Table 2-3, p. 51589). Figure 4 of Reference 5 shows the sedime nt sampling locations, and Table 2 of Reference 5 describes the sediment samples (Refs. 5, pp. 27, 31-40; 17A, pp. 1-30). The sample descriptions are also presented in Table 5 below (Refs. 5, pp. 31 – 40; 17A, pp. 1-30).29 TABLE 5 SEDIMENT SAMPLE DESCRIPTIONS SAINT CLAIR SHORES DRAIN SITE (Ref. 5, pp. 31-40; 17A, pp. 1-30)

SAMPLE NUMBER DEPTH OF WATER AT

SAMPLE LOCATION UNIT THICKNESS LITHOLOGICAL DESCRIPTION SAMPLE INTERVALS AND COMMENTS
SD1 8ft 0-2 in. Wet, dark gray, fine to coarse sand with silt, gravel, some organic plant matter, and shell fragments. SD1 sample collected from 0-9 in.

2-9 in. Moist, grayish brown clay with some silt. SD2 7 ft. 0-2 in. Wet, blackish gray silt with some fine sand and clay. SD2 sample collected from 0-8 in. 2-7 in.

7-15 in. Very moist, gray, loose, silt and clay.
Moist gray silty clay with trace sand, loose. SD3 8.5 ft. 0-4 in. Wet, dark blackish gray, loose silt with some fine sand. SD3 sample collected from 0-10 in.
4-10 in. Very moist, dark gray, silty fine sand with some clay. SD5 9 ft. 0-13 in. Very moist, blackish gray, loose silt with some fine sand and clay. SD5 sample collected from 0-8 in. SD6 6 ft. 0-6 in. Wet, dark gray, loose, silty, fine sand. SD6 sample collected from 0-10 in.
6-10 in. Very moist, grayish brown, loose, silty clay. SD7 7 ft. 0-4 in. Wet, blackish gray, fine sand with some silt and organic matter. SD7 sample collected from 0-9 in.

4-18 in. Wet, greenish brown, fine to medium sand with some silt and trace gravel.30 SAMPLE NUMBER DEPTH OF WATER AT

SAMPLE LOCATION UNIT THICKNESS LITHOLOGICAL DESCRIPTION SAMPLE INTERVALS AND COMMENTS
SD16 8.5 ft. 0-2 in. Wet, greenish gray, fine to medium sand with trace silt and plant matter and soil fragments. SD16 sample collected from 0-10 in.

10-16 in. Moist, grayish brown, clay with some silt. SD19 8 ft. 0-1 in. Wet, greenish gray, fine to medium sand with trace plant material and silt SD19 sample collected from 0-6 in.

10-16 in. Moist, variegated - grayish brown/greenish gray, clayey silt. SD20 6 ft. 0-2 in.

3-11 Wet, greenish gray, medium sand with trace silt.
Moist, greenish gray, clay SD20 sample collected from 0-7 in.

SD26 8.5 ft. 0-2 in. Wet, greenish gray, silty fine sand with organic matter. SD26 sample collected from 0-7 in.
2-4 in. Wet, dark gray, fine sand with some silt and organic matter and shell fragments.

4-10 in. Very moist, brownish gray, clayey fine sand. SD27 6 ft. 0-15 in. Wet, greenish gray, fine to medium sand with trace silt some root matter in top couple of inches. SD27 sample collected from 0-8 in.

SD29 10 ft. 0-0.5 in. Wet, gray silt and fine to medium sand with trace organic root material and shell fragments.. SD29 sample collected from 0-7 in.

0.5-7 in. Moist, grayish brown clay with some silt.

Background Sediment Samples
The Lange Street Canal and Revere Street Canal are c ontiguous to Lake Saint Clair, and the SCSD outfall drain is located upstream of the canals. Sediment samples SD1, SD16, SD19, SD20, SD27 and SD29 collected from Lake St. Clair are identified to repr esent background levels. SD 16, SD19, SD20, SD27 and SD29 were collected closer to the canals. These samp les were selected as background samples because PCBs were not detected in these samples. Non detection of PCBs in these samples sugg ests that the PCBs are not widespread in this portion of Lake St. Clair. Th e locations of the background sediment samples SD20 and31 SD27 are very close to canals and appear to be with in the zone of sediment deposition from other nearby canals (Ref. 5, pp. 27). Table 6 below summarizes th e analytical results for background sediment samples SD1, SD16, SD19, SD20, SD27, and SD29.

TABLE 6 BACKGROUND SAMPLES PCB (AROCLOR) CONCENTRATIONS
Sample No. Hazardous Substance Concentration (μg/kg) Q SQL (μg/kg) Sampling Date References

SD1/E2955 Aroclor-1248 39 U 39 7/29/2008 Refs. 5, pp. 44, 76-82, 88-92, 115; 17A, p. 1)

SD27/E2981RE Aroclor-1248 41 U 41 7/29/2008 Refs. 5, pp. 53, 261, 269, 251-258, 324; 17A, p. 27)

SD29/E2983 Aroclor-1248 38 U 38 7/29/2008 Refs. 5, pp.54, 262, 269, 251-258, 326; 17A, p. 29)

SD16/E2970 Aroclor-1248 41 U 41 7/29/2008 Refs. 5, pp. 49, 76-81, 86, 88-92, 138; 17A, p. 16)

SD19/E2973 Aroclor-1248 38 U 38 7/29/2008 Refs. 5, pp. 50, 76-81, 86, 88-92, 141; 17A, p. 19)

SD20/E2974 Aroclor-1248 39 U 39 7/29/2008 Refs. 5, pp. 50, 76-81, 87-92, 142; 17A. 20)

Notes: μg/kg - Microgram per kilogram PCB - Polychlorinated biphenyl Q - Laboratory data qualifier SD - Sediment sample SQL – Sample Quantitation Limit, the SQL was derive d from the non-detected Aroc lors from the respective samples. U - Not detected

PCB Contaminated Sediment Samples
PCBs were detected above backgroun d sample levels in sediment sample s collected from the canals and Lake St. Clair. Observed release through chemical analysis has been documented because PCBs were not detected at or above the detection limit in the background sediment samples and the concentr ations of PCBs in the release sediment samples were above the detection li mits. Furthermore sediment sample SD26 was collected close to the Lange Street and Revere Street canals ( see Figure 4 of this HRS documentation record). Table 732 below summarizes the PCB concentrati ons detected above the reference cr iteria in the investigative sediment samples.

TABLE 7 SEDIMENT RELEASE SAMPLES PCB (AROCLOR) CONCENTRATIONS
Sample No. Hazardous Substance Concentration (μg/kg) Q SQL (μg/kg) Sampling Date References

SD2/E2956DL (Lange Street Canal) Aroclor-1248 6,800 DL 940 7/30/2008 Refs. 5, p. 43, 75-80, 81, 83, 90, 122, 143; 17, p. 1; 17 A, p. 2
SD3/E2957DL (Lange Street Canal) Aroclor-1248 1,500 DL 290 7/30/2008 Refs. 5, p. 43, 75-80, 83, 90, 124, 143 ; 17, p. 1; 17 A, p. 3 SD5/E2959DL (Revere Street Canal) Aroclor-1248 2,800 DL 420 7/30/2008 Refs. 5, p. 44, 75-80, 84, 90, 127, 143; 17, p. 1; 17 A, p. 5 SD6/E2960 (Revere Street Canal) Aroclor-1248 260 65 7/30/2008 Refs. 5, p. 44, 75-80, 84, 90, 128, 143; 17, p. 1; 17 A, p. 6 SD7/E2961 (Revere Street Canal) Aroclor-1248 140 45 7/30/2008 Refs. 5, p. 45, 75-80, 84, 90, 129, 143; 17, p. 1; 17 A, p. 7 SD26/E2980RE (Lake Saint Clair) Aroclor-1248 41 39 7/29/2008 Refs. 5, p. 260, 252- 258, 268, 321; 17, p.1; 17 A, p. 26 Notes: μg/kg - Microgram per kilogram DL - Sample or extract reanalyzed at higher dilution f actor because the concentration of the analyte exceeded upper calibration range. The sample concen trations are for reanalyzed sample. PCB - Polychlorinated biphenyl Q - Laboratory data qualifier SD - Sediment sample SQL – Sample Quantitation Limit, the SQL was derive d from the non-detected Aroc lors from the respective samples.
The background and the release sediment samples were similar because the samples: (1) were collected using the same equipment and procedures as is documented in Reference 17 A; (2) were collected within the same time frame (29 and 30 April 2005) and therefore, the same weather conditions (Ref. 17A , pp. 1-30 ); (3) were collected within the canals contiguous with Lake St. Clair and within Lake St. Clair (R efer to Figure 4 of this HRS documentation package); (4) were analyzed using the same methods as documented in Appendix E of Reference 5; and (5) were collected from similar depths (Refer to Table 4 of this HRS documentation record).

In accordance with the HRS, if an observed release can be established for a watershed, an observed release factor value of 550 should be assigned to that watershed (Ref. 1, p. 51609).33 Observed Release Factor Value: 550

Attribution

The sediment samples collect ed from the SCSD sewer pipes in 2002 were found to contain PCBs at high concentrations at the intersection of Harper Avenue and Bon Brae Street (Ref. 8, p. 11). This suggested that the PCBs were allegedly disposed of in the SCSD sewe r pipes area near Bon Brae Street and Harper Avenue by an unknown entity. The PCB contamination has also b een detected in the Lange Street and Revere Street canals and Lake Saint Clair (Refs. 5, p. 16; 7, p. 9, 37). Because their discharge point is on the canals, the SCSD sewer pipes carried and discharged the PCBs into the Lange Street and Revere Street canals causing sediment contamination. The Lange Street and Revere St reet canals are contiguous to Lake Saint Clair. The PCB contamination was then carried from the Lange Street and Revere Street canals into Lake Saint Clair. This transport mechanism has contaminat ed sediments in the Lake Saint Clai r. Therefore, the PCBs detected in the Lange Street Canal, Revere Street Canal and La ke Saint Clair are attributable to Source 1 because the PCBs released in the SCSD sewer pipes were carried to the outfall that discharged into the Lange Street and
Revere Street Canals and Lake Sa int Clair. Furthermore, sediment sample SD26 was collected from close proximity to Lange Street Canal and Revere Street Cana l. Since SD26 is very close to the Lange Street and Revere Street canals and is probably within the sediment deposition area of these canals the contamination detected in SD26 is most likely from Lange/Revere Street canals. Furthermore, th e location of background samples SD19, SD20, SD27, and SD29 around the release sample SD26 effectively serve to isolate the portion
of the lake under the site’s influen ce indicating that the impact to Lake St. Clair in SD26 has come from the
SCSD source and not from other offs ite source(s) of contamination.

4.1.2.1.2 Potential to Release 4.1.2.1.2.1 Potential to Release by Overland Flow
Because an observed release has been documented throug h chemical analysis (Section 4.1.2.1.1 of this HRS documentation record), the potential to release by overland flow has not been scored (Ref. 1, Section 4.1.2.1.1).

Potential to Release by Overland Flow: NS

4.1.2.2 Drinking Water Threat – Waste Characteristics

4.1.2.2.1 Toxicity/Persistence
Table 8 below provides Drinking Water Threat Waste Ch aracteristics Factor Values for analytes present in the source at the SCSD Site (see Sections 2.2.2 a nd 4.1.2.1.1 of this HRS documentation record).34 TABLE 8 DRINKING WATER THREAT WASTE CHARACTERISTICS FACTOR VALUES

Hazardous Substance Source No. Toxicity Factor Value Persistence Factor Value* Toxicity/ Persistence/ Factor Value (Table 4-12) References

PCBs 1 10,000 1.0 10,000 Ref. 1, Table 4-12; Ref. 2, p. BI-10 Note: *Persistence value assigned based on rivers, oceans, coastal tidal waters and Great Lakes (Note: Lake St. Clair is located between lakes Huron and Erie; Lake St. Clair is the smallest lake in the Great Lakes system) (Ref. 33, p. 1).

The hazardous substances with the highest toxi city/persistence factor value are PCBs.
Toxicity/Persistence Factor Value: 10,000

4.1.2.2.2 Hazardous Waste Quantity
Table 9 below summarizes the source hazardous waste quantity value.

TABLE 9 DRINKING WATER THREAT WASTE CHARACTERISTICS FACTOR VALUES

Source

No. Source Hazardous Waste Quantity Value (HRS Rule Section 2.4.2.1.5) Is Source Hazardous Constituent Quantity Data Complete? (Y/N) 1 >0 N

Source : >0
According to Section 2.4.2.2 of the HRS, a minimum pathway hazardous waste quantity factor value of 100 was assigned based on that the hazardous constituent quantit y is not adequately determined, and based on the
Level II concentrations in the surface migration pathway (Section 2.4.2.2).

Hazardous Waste Quantity Factor Value: 100
4.1.2.2.3 Waste Characteristics Factor Category Value
The waste characteristics factor category value was assigned based on the waste characteristics product. The waste characteristics product is the product of the toxi city/persistence factor value and the hazardous waste quantity factor value (Ref. 1, Section 4.1.2.2. 3). Values from the substance with the highest toxicity/persistence factor value for the watershed (PCBs) were used (Ref. 1, Section 4.1.2.2.3).

A hazardous waste quantity factor value of 100 was assigned as described above (R ef. 1, Section 2.4.2.2).Toxicity/Persistence Factor Value: 10,000
Hazardous Waste Quantity Factor Value: 100
(Toxicity/Persistence x Hazardous Waste Quantity):
10,000 × 100 = 1.0 × 10 6
(subject to a maximum product of 1 × 10 8 ) (Ref. 1, Section 4.1.2.2.3, p. 51613)
A waste characteristics pr oduct value of 1.0 × 10 6 receives a waste characteristics factor category value of 32 (Ref. 1, Section 2.4.3.1, Table 2-7).

Waste Characteristics Factor Category Value: 32

4.1.2.3 Drinking Water Threat Targets

4.1.2.3.1 Nearest Intake
Analysis of sediment samples from Lake St. Clair i ndicate that PCB concentrations have met the observed release criteria (see Section 4.1.2.1.1 of this HRS doc umentation record). The observed release of PCBs
establishes a zone of actual Level II contamination. Drinking water intakes are not subject to actual contamination because they are located outside the zone of actual contamination; therefore, based on available information, these drinking water intakes are not affected by actual contamination. The nearest drinking water intake is located approximately 5.68 miles from the PPE a nd is not subject to actual contamination. Lake St. Clair is located between lakes Huron and Erie; Lake St. Clair is the smallest lake in the Great Lakes system (Ref. 33, p. 1). The depth of Lake St. Clair is greater than 20 feet and less than 200 feet (Ref. 24, p. 8) The dilution weight for Lake St. Clair from Ref. 1, Table 4-13, is 0.00001 (modest depth ocean zone or Great Lakes). In accordance with Ref.1, Section 4.1.2.3.1, by multiplying the dilution weight (0.00001) by 20, a factor value of 0.0002 was calculated. The product was rounded to the nearest integer and a factor value of 1 was assigned for the nearest intake (Ref. 1, Section 4.1.2.3.1).

4.1.2.3.2 Population

4.1.2.3.2.2 Level I Concentrations

Level I concentrations have not been est ablished based on the samples collected.

4.1.2.3.2.3 Level II Concentrations
No drinking water intake located within the in-wat er segment has met the Level II actual contamination
criteria.

354.1.2.3.2.4 Potential Contamination
Within the 15-mile TDL two drinking water intakes are locat ed in Lake St. Clair, and one intake is located at the mouth of the Detroit River (Ref. 5, p.18). The inta kes are denoted on the 15-mile TDL map (Ref. 16, p. 1). The City of Mount Clemens and Gross Pointe/Highland Park operate the intakes on Lake St. Clair (Refs. 5, p. 18; 25, p.1; 27, p.1; 29, p. 1). The populations served by the City of Mount Clemens and Gross Point/Highland Park intakes have not been included becau se they would have no effect on the potential factor
value.

The Detroit Water and Sewerage Depa rtment operates three intakes, one at the mouth of the Detroit River (Water Works Park intake), one approximately 30 miles downstream of the mouth of the Detroit River (Southwest intake), and one in Lake Huron (Lake Huron intake) (Ref. 31, p. 1). The water from Water Works Park intake is supplied to three water treatment plan ts: Water Works Park Water Treatment Plant, Spring
Wells Water Treatment Plant and Northeast Water Treatme nt Plant (Ref. 31, p.1). The water from Southwest intake is supplied to Southwest Water Treatment Plant and water from Lake Huron intake is supplied to Lake Huron Water Treatment Plant (Ref. 31, p.1). All five wa ter treatment plants are interconnected so that it would
allow distribution of water to cust omers throughout the system (Ref. 31, pp. 1, 2). However, the water distribution system piping is connected such that wa ter from one system can be supplied to another system during emergency and periods of high demand (Ref. 31, p. 2). In the last 24 years water has never been exchanged between the three intakes (Ref. 31, p. 2). The Water Works Park intake lies within the 15-mile TDL (Ref. 16, p. 1). The City of Detroit serves approximately 3.5 million people (Ref. 31, p. 1). Based on the production rates the Water Works Park intake provides appr oximately 63 percent of the water (Ref. 31, p. 1). Based on the Water Works Park intake providing 63 pe rcent of the water required, the intake serves approximately 2,205,000 people (Ref. 30, p. 1,2). Sin ce the Water Works Park intake appears to be located closer to the Lake St. Clair (Ref. 16) and the zone of in fluence of the intake could extend to Lake St. Clair, the dilution weight for Lake St. Clair is used. The depth of Lake St. Clair is greater than 20 feet and less than 200 feet (Ref. 24, p. 8). Using Table 4-14 from the HRS, the value for the moderate ocean zone or Great Lakes (depth 20 to 200 feet), and the population of 2,205,0 00, a dilution-weighted population value of 16 was assigned (Ref. 1, Section 4.1.2.3.2.4). This value (16) was divided by 10, rounded to the nearest integer, and assigned as the potential contamination factor for the watershed (Ref. 1, Section 4.1.2.3.2.4).

Potential Contamination Factor: 2

4.1.2.3.5 Calculation of Population Factor Value
The population factor value is equal to 2 as calculated below.
Level I Concentrations (0) + Level II Concentr ations (0) + Potential Contamination (2) = 2

364.1.2.3.3 Resources
Industries that are supplied by the Detroit water system include breweries, the auto mobile industry, and steel mills (Ref. 31, p. 2). Since water from the Detroit wate r intake within the 15-mile TDL is used for commercial food preparation, therefore, in accordance with the HR S Section 4.1.2.3.3 a Resour ce Factor Value of 5 is assigned.

Resource Factor Value: 5

4.1.2.3.4 Calculation of Drinking Water Threat - Targets Factor Category Value
The Drinking Water Threat - Targets Factor Category Value was calculated by summing the nearest intake (1) and population (2), and resource (5) factor values fo r the watershed as summarized below (Ref. 1, Section 4.1.2.3.4).

Calculation of Drinking Water Threat – Targets Factor Category Value: 1 + 2 + 5 =8

4.1.3.2 Human Food Chain Threat -- Waste Characteristics

4.1.3.2.1 Toxicity/Persi stence/Bioaccumulation

Table 10 below summarizes the Human Food Chain Thr eat - Waste Characteristics Factor Values for PCBs present in the source at the SCSD Site (see Sections 2. 2.2 and 4.1.2.1.1 of this HRS documentation record).

TABLE 10 HUMAN FOOD CHAIN THREAT - WASTE CHARACTERISTICS FACTOR VALUES

Hazardous Substance Source No. Toxicity Factor Value Persistence Factor Value* Bioaccumulation Factor Value* Toxicity/ Persistence/ Bioaccumulation Value (Table 4

- 15) Reference

PCBs 1 10,000 1.0 50,000 500,000,000 Ref. 2, p. B1-10 Note: *Persistence factor value and bioaccumulation factor valu e for fresh water, because Lake St. Clair is a fresh water body, and therefore, the targets are in fresh water.
The hazardous substance having the highest toxici ty/persistence/bioaccumulation value of 5 x 10 8 is for PCBs.

Toxicity/Persistence/Bioaccumulation Factor Value : 5 x 10 8 (500,000,000)

4.1.3.2.2 Hazardous Waste Quantity

Table 11 below summarizes the Hazar dous Waste Quantity Value and the Containment Value for Surface Water for the source at the SCSD site (see Sections 2.2.2 and 4.1.2.1.1 of this HRS documentation record). 3738 TABLE 11 HAZARDOUS WASTE QUANTITY VALUE AND CONTAINMENT VALUE FOR SURFACE WATER

Source Source Hazardous Waste Quantity Value* Containment Value for Surface Water** 1. Other – Sewer pipes and contaminated soil surrounding sewer pipes >0 10

Notes: * - See Section 2.4.2.2 of this HRS documentation record ** - Ref. 1, p. 51610, Table 4-2
The source Hazardous Waste Quantity Value is unknown but greater than zero. According to Section 2.4.2.2 of the HRS, a minimum pathway hazardous waste quantity factor value of 100 was assigned based on that the hazardous constituent quantity is not adequately determin ed, and based on the Level II concentrations in the surface migration pathway (Section 2.4.2.2).
Hazardous Waste Quantity Factor Value: 100
(Ref. 1, p. 51591, Table 2-6)
4.1.3.2.3 Waste Characteristics Factor Category Value
4.1.2.2.3 Waste Characteristics Factor Category Value
The waste characteristics factor category value was assi gned based on the waste characteristics product. The waste characteristics product is the product of the toxi city/persistence factor value and the hazardous waste quantity factor value (Ref. 1, Section 4.1.2.2. 3). Values from the substance with the highest toxicity/persistence factor value for the watershed (PCBs) were used (Ref. 1, Section 4.1.2.2.3).

A hazardous waste quantity factor value of 100 was assigned as described above.
Toxicity/Persistence Factor Value: 10,000
Hazardous Waste Quantity Factor Value: 100
(Toxicity/Persistence x Hazardous Waste Quantity):
10,000 x 100 = 1.0 x 10 6

Bioaccumulation Potential Factor Value: 50,000
(Toxicity/persistence x hazardous waste quantity) x food chain bioaccumulation factor value: 5 x 10 10 (Ref. 1, p. 51592) (1 x 10 6 ) x(5 x 10 4 ) = 5 x 10 10 Waste Characteristics Factor Category Value : 320 (Ref. 1, p. 51592, Table 2-7)39 4.1.3.3 Human Food Chain Targets

Level I concentrations for the Human Food Chain Threat were not evaluated.

The zone of actual contamination associated with the surface water pathway is bounded by sediment samples SD2 and SD3 collected from Lange Street Canal; SD5, SD 6 and SD7 collected from Revere Street Canal, and SD26 collected from Lake St. Clair. All of these sediment samples meet observed release criteria (Refer to Section 4.1.2.1.1 of this documentation record). Lake St. Clair is considered a fishery; fish are caught for human consumption within the zone of actual contamination, based on interviews with persons who fish within this zone (Refs. 18, p. 1;19, pp. 9, 10; 34). Lake St. Clair also is used for boating, and swimming (Ref. 18, p. 1). The most likely source of human exposure to PCBs is through the eating of contaminated fish (Ref. 20, p. 11). The Michigan Department of Community Health (M DCH) has issued a Do Not Eat advisory for several fish species caught in Lake St. Clair because of PCB contamination (Refs. 20, pp. 11, 12; 21, p. 8; 22, p. 8).

4.1.3.3.1 Food Chain Individual
There are Level II releases of contaminants having a bioaccu mulation factor of 500 or greater to Lake St. Clair, which is considered a fishery (see Section 4.1.3.3 of this HRS documentation record). The observed release has been established by the presence of hazardous substan ces in an observed release through chemical analysis (Ref. 1, p. 51620); therefore, a food chain individual factor value of 45 was assigned.

Food Chain Individual Factor Value : 45
4.1.3.3.2 Population

4.1.3.3.2.1 Level I Concentrations

Level I concentrations were not evaluated.

Level I Concentrations: NS

4.1.3.3.2.2 Level II Concentrations
An observed release of PCBs has been documented (see Se ction 4.1.2.1.1 of this HRS documentation record). Lake St. Clair is considered a fishery (Refs. 18, p. 1; 19, pp. 9, 10). The zone of actual contamination is bounded by sediment samples SD2 and SD3 collected fro m Lange Street Canal; SD5, SD6 and SD7 collected
from Revere Street Canal and SD26 collected from Lake St. Clair. All these sediment samples meet observed release criteria (refer to Section 4.1.2.1.1 of this documentation record). Lake St. Clair also is used for boating, and swimming (Ref. 18, p. 1). The most likely source of human exposure to PCBs is through the eating of contaminated fish (Ref. 20, p. 11). The MDCH has i ssued a Do Not Eat advisory for several fish species caught in the Lake St. Clair because of PCB contamination (R efs. 20, pp. 11, 12; 21, p. 8; 22, p. 8; 23, p. 39). The fish caught in Lake St. Clair within the zone of contamination described above are utilized for human40 consumption (Ref. 34, p. 1). While the exact amount is unknown, the amount of fish caught for consumption by humans within the zone of actual contamination is estim ated to be greater than 0 pounds (Ref. 34, p. 1). As instructed in Section 4.1.3.3.2.2 and Table 4-18 of the HRS (Ref. 1 p. 51621), the human food chain population was assigned a value of 0.03.

Level II Concentrations : 0.03

4.1.3.3.2.3 Potential Contamination
Fisheries (the Detroit River) are present downstream of releases associated with the site (Ref. 19, p. 9); however, downstream fisheries were not included because they would not significantly impact the site score.

4.1.4 Environmental Threat
Sensitive environments (wetlands) are located within the TDL (Refs. 22, 23); however, these targets were not included because they would not signif icantly impact the site score.