United States Environmental Protection Agency 5 Post Office Square, Suite 100

Boston, MA 02109-3912

May 31, 2011

Andrew Silfer, P.E. General Electric Company 319 Great Oaks Boulevard Albany, NY 12203

Sent via electronic and U.S. First Class Mail

Re: Conditional Approval ofGE's November 2010 Revised Final Removal Design/Removal Action Work Plan for Silver Lake Area

Dear Mr. Silfer,

EPA has completed its review ofGE's report entitled Revised Final Removal Design/Removal Action Work Plan/or Silver Lake Area dated November 2010 (the Work Plan).

Pursuant to Paragraph 73 of the CD, EPA, after consultation with the Massachusetts Department of Environmental Protection (MassDEP) and the Natural Resource Trustees (the Trustees), approves the Work Plan subject to the following conditions (note that the conditions of the July 9,2010 Conditional Approval Letter (CAL) are referenced where applicable to streamline the review process):

1. As we have discussed, EPA does not concur with GE's assumptions in the Work Plan that sediment/fill/soil near the edge of water will consolidate to the point such that, in all areas, the top of the placed isolation layer/cap material and annor stone (26 inch depth total) will match pre-existing sediment/soil elevations (see Appendix. D, Sheet 18b, Note 10). EPA notes that if this assumed consolidation does not occur, there would be both a loss of flood storage capacity and a loss of aquatic habitat. Since the Statement of Work states that "all practical measures will be taken to minimize and mitigate any adverse impacts from the work" (Attachment B, Applicable or Relevant and Appropriate Requirements, Table 3 - page 2, Clean Water Act § 404 Requirements), and neither the Decree nor the SOW contemplate significant loss of flood storage or aquatic habitat, GE shall redesign the near-shore cross-sections of the cap/isolation layer and armor stone to minimize such losses, including use of assumed consolidation rates for this material that, where justified, are significantly less than the currently assumed rate of 100%. GE shall describe the basis for the assumed rates of consolidation, including, but limited to, infonnation obtained during the May 5, 2011 investigation.

GE shall also revise the appropriate cross-sections to incorporate the design modifications that we have discussed including:

I

Use of a lO-inch sand isolation layer (with geotextile) under the annor stone in the lake; Use of a 6-inch layer of annor stone within the west shore annor configuration area; Use ofa IO-inch isolation layer (with geotextile) on the shrub-scrub island; Following removal of the existing vegetation on the shrub-scrub island, placement of the cover materials on the existing grade of the island such that the final grade will be approximately two inches higher than the previous design (but still approximately one foot above the mean water surface elevation; Placement of annor stone at grade on the banks where other soil removal activities are not being perfonned (except at the toe of slope where stone will be placed below grade to blend into the undClWater armor stone), and also securing the geotextile under the annor stone with pins, as necessary, rather than through the use of anchor trenches; Revisiting the designs of cross-section #6 (4th St. outfall) and #53 (outfall to river) as necessitated by these design modifications and to level the final surface grade as appropriate; Addition oftopsoiVseed rather than stone when blending the upper limit of armor stone into the adjacent bank (unless too steep); and Placement of a sand/topsoil mixture together with herbaceous seeding to fill and vegetate the void spaces of the annor stone where such voids are above the mean water surface elevation of975.9 feet (such topsoil and seeding to be excluded from the Work Plan's monitoring and maintenance requirements). The species and seeding rate shall be consistent with the New England Wet Mix specified on drawing D-502 (Silver Lake Walking Path), Appendix D of the Work Plan. GE shall propose the sand/topsoil mixture for EPA approval.

In addition, GE shall demonstrate that it will obtain sufficient flood storage compensation to offset the loss of flood storage capacity that would result should the actual consolidation of this material be less than assumed. In addition, in the event that the actual consolidation of this material is less than assumed and that as a result, based on an evaluation to be conducted by EPA approximately three years after placement of the isolation layer and annor stone, there is a significant loss of aquatic habitat, EPA reserves the right to require that GE provide mitigation to offset this loss of aquatic habitat by creating new aquatic habitat elsewhere as approved by EPA.

GE shall also revise all related sections of the Work Plan, Notes and Technical Drawings accordingly (e.g., Sheet #11, Note 11; Sheet #18A, Sheet #188, Cross-sections I through 70, etc.).

GE shall also include a separate version of Cross-sections 16 through 65 1 showing how these would look immediately upon construction (rather than after consolidation), so that the contractor will have a better understanding of how to construct the near-shore and bank areas.

l.b As specified in Attachment 1 of the SOW. for those areas of the shrub-scrub island where exposed annoring is present (i.e. , above elevation 975.9 feet), the voids in the stone shall be

lCross-sections 1-15 and 66-70 will have all necessary sediment removed (i.e., 0% consolidalioo assumed) so that these sections do oot need both sets of drawings.

2

filled with topsoil and seeded with a wetlands mixture of herbaceous species (see p.18 of Attachment I for species and seeding rate).

2. As we have also discussed, the City of Pittsfield is concerned about traffic impacts due to the closing of Silver Lake Boulevard (SLB) for this project. GE shall keep the closing of SLB to a minimum (e.g., closure during the second construction season only) and consider other alternatives to full closure ofSLB for those periods when SLB is needed for staging (e.g., closing one lane instead of both lanes). GE shall address these road closure issues accordingly in the Traffic Control Plan.

3. Section 6.6.5.4, Gravel Habitat Layer: The current Technical Specifications define the gradation for this layer as follows:

3 inch No. 200

Percent Passing

100 10-30

However, to ensure effective ecological structure and function, and consistent with consultation with the Trustees, GE shall replace this gradation specification with the following, and, if it believes appropriate, recommend additional sieve specifications between the 2.5 inch and No. 200 sizes:

Sieve Percent Mass Passing (minimum)

2.5 inch 100 I inch 50 No. 200 (0.003") 30

4. CAL Condition #16:

a - for materials stockpiled inside buildings (e.g., building 65), GE shall specify that materials will be transported off-site within 90 days, provided the material is sufficiently dewatered so that it is able to pass the paint filter test and can be transported in vehicles to an off-site disposal facility;

b - for materials stockpiled in outdoor areas, GE shall specify that such stockpiles not exceed 30 days in place or as soon thereafter as the material in the stockpiles are sufficiently dewatered to be transported in vehicles to the temporary in-building stockpile at the GE Plant;

c - for materials stockpiled in outdoor areas, pursuant to 40 CFR 761.65(c)(9), GE shall specify that liners and covers be "constructed of materials that have appropriate chemical properties and sufficient strength and thickness to prevent failure due to ... the stress of daily operation." GE shall specify, at a minimum, the use of heavy duty impenneable tarps for covers of outdoor stockpiles. EPA is concerned that a single sheet of 4 or 6 mil polyethylene sheeting, as currently proposed in the Work Plan, would likely be punctured during typical daily operations (e.g., from

3

heavy stones or debris being placed on to the liner, impacts from heavy equipment - bucket teeth, treads, etc.) and therefore may not be sufficient to prevent contaminant migration, especially for saturated soil and sediment. GE shall therefore use 30 mil HDPE bottom liners for outside staging areas for saturated soils and sediments.

d - GE shall specify that "outdoor areas not subject to future excavation" only be used for stockpiling if no other areas are available.

e - GE shall require that polyethylene sheeting be placed on all land areas underneath the "swing-arc" of excavator or back-hoe buckets when excavated soil/sediment is being moved over outdoor areas not subject to future excavation (and when such areas are not to be used for stockpiling) so that such areas are not contaminated by spillage from said buckets.

f - After all material is transported off-site, GE shall remove any residual soil from building floors by sweeping or other mechanical means and shall pressure-wash the floor. Wash water can be treated at GE' s on-site water treatment facility. In addition, GE shall ensure that the roofs of the buildings remain intact and shall take efforts to control windborne emissions from the soil (if any) that is stored within the buildings.

GE shall modify the Work Plan and Technical Drawings and Specifications (Appendix D and E) accordingly to reflect these requirements.

5. CAL Condition #18: Stonnwater Outfalls/Structures

GE shall provide additional details on the design assumptions/parameters and clarification of the approach used for all of the proposed outfall protection designs.

GE shall revise the outfall protection design for the four swales (outfa11s 16,23,28 and 30) to include assumptions and design inputs related to actual field conditions rather than calculating protection measures based on potentially conservative assumptions related to pipe geometry.

EPA notes that outfall 9 (invert elevation 978.9') will discharge approximately 1.3 feet above the cap annor layer (top elevation 977 .67' along eastern shore) and will thus require additional riprap for erosion control. This is inconsistent with Note I on Technical Drawing 22 ("No additional annor necessary for outfall protection due to presence of annor layer materials."). GE shall therefore correct Technical Drawing 22 accordingly and review all other outfalls in this regard to ensure accuracy.

In addition, in areas where the designed riprap size for drainage apron protection exceeds the riprap size designed for the abutting bank annor protection, GE shall clarify if the apron protection riprap will be tenninated below, at, or above the water line.

6. CAL Condition #21, Appendix H, NAPL Contingency Plan:

Section 2:

4

I SI paragraph, last sentence: GE shall revise this sentence to read: "Such measures will be deployed during construction to minimize the potential for NAPL impacts to the lake and/or the transport ofNAPL to the Housatonic River in the event that NAPL or surface water sheens or oil-stained soils are observed."

2nd paragraph: CAL Condition # 17 required sheet pile and booms deployed outside of the sheet pile for all bank cuts 3 feet below mean water level. Section 6.2.5.1 of the Work Plan correctly addresses this requirement; however, the NAPL Contingency Plan fails to mention that booms will be deployed along with (outside of) this sheetpiling. For additional protection, GE shall also deploy booms on the inside of the sheetpile. Similarly, GE shall deploy booms inside and outside of the silt curtain surrounding the shrub-scrub island excavation as a preventive measure for NAPL control.

In the third-to-Iast sentence in this Section 2, a word is missing between "and" and "for".

Section 3:

I st bullet: insert "immediately" between "EPA will be" and "notified".

2nd bullet, 1 st sentence: revise this sentence to read: "To mitigate the migration ofNAPL to the lake from the in-shore area of construction, any NAPL observed will be removed, and any NAPL-stained soils will be removed to the extent practicable."

3m bullet, 2nd sentence: delete "immediately"

3m bullet, 2nd sentence: change "GE may continue" to "GE will continue".

3rd bullet, last sentence: revise this sentence to read: "In other areas where NAPL or stained materials within the project work zone that have generated sheens have been observed and/or removed, a low-permeability barrier and/or materials with sorptive capacity (e.g., organo-clay, AquabJockTM) will be placed to mitigate the potential for any remaining impacted materials to reach the lake."

GE shall revise Appendix H accordingly.

7. CAL Condition #23: Additional survey control points may be required within polygons to account for significant grade changes, and certain polygons may be subject to multiple slope correction factors if slopes vary significantly. GE shall acknowledge that EPA's review may result in a request for additional survey points.

8. CAL Condition #24: See comment 4.c above.

Also, once excavated bank soils/sediments pass the paint filter test (but not prior to passing) GE may add polymer or other drying agents as necessary to further "dry" the excavated material to ensure safe transport of this material. (GE may also include here the provision in the last sentence of Section 7.2 allowing GE, in certain limited circumstances, to request a

5

risk-based detennination by EPA under the TSCA regulations that would allow the addition of drying agents to material that still does not pass the paint filter test even after implementation of all practical actions.)

9. CAL Condition #26 - Appendix E, Technical Specifications

Topsoil, Seeding, and Mulch - Section 1.03B states the fertilizer application rate is identified in Section 3.01 B; however, no such Section is included. Section I.03B states the soil laboratory will provide fertilizer recommendations for composition and application rates; however Section 2.01 B states fertilizer will be a standard 511 011 0 composition. In addition, the seed mix composition as well as sections of the Specification regarding execution and maintenance are missing (although the seed mix composition is listed on Sheet D-502 of the Technical Drawings). Lastly, GE shall not apply fertilizer for herbaceous cover without prior approval from EPA. GE shall revise the Specifications to follow the fonnat of the Topsoil, Seeding, and Mulch specification in the Revised Final RDIRA Work Plan for East Street Area 2 - South dated April 2010.

Erosion Control Blanket. GE shall include a requirement that all staples or pins that hold the blanket in place are biodegradable.

Geotextile Fabric - Section 2.02C states "non-woven" geotextile for decon areas while Appendix D, Drawing 26 states "woven" geotextile for decon areas. Figures and construction drawings routinely cite "Mirafi" geotextiles. Mirafi is a trade name for geotextiles produced by TenCate Geosynthetics; however, TenCatc Geosynthetics is not listed as an approved manufacturer in the specification. GE shall modify the Technical Drawings and Specifications accordingly to resolve these inconsistencies and clearly document the geotextile requirements for all applications.

Bituminous Concrete - GE shall revise the Specification to require a submittal that contains a certification from the asphalt supplier that the material is fonnulated in accordance with the Specification.

GE shall include specifications for fencing and guardrails.

10. CAL Condition #32: GE shall clarify that the protective procedures used for containing dewatering sediment and collecting decant shall be the same as those used for stockpiling in areas not subject to future excavation.

II. CAL Condition #42:

See comment # 1 above. The evaluation of Flood Storage Capacity (FSC) and tables K-4 and 6-2 shall be revised based on the redesigned near-shore cross-sections. GE shall provide documentation showing that if the assumed consolidation of sediment/fill/soil near the edge of water does not occur, that GE still has sufficient FSC off-sets to account for this potential loss of FSC.

6

OE shall provide documentation to EPA demonstrating that the Pittsfield Conservation Commission concurs with PEDA'a allocation of certain FSC to GE for the Silver Lake project.

OE shall revise Table K-5 to account for the FSC PEDA gave to the City for the Deming Park project.

12. CAL Condition #53: During bank soil removal activities, OE shall collect PCB and TSS water quality data weekly, rather than monthly as the Work Plan currently proposes. Should it become clear based on data that these activities are not significantly impacting water quality, than GE may propose to EPA, for review and approval, a monitoring approach less frequent than weekly. OE shall not implement such a modified monitoring approach without EPA's approval.

Section 8.1.4, 2nd para., I st sentence: for clarity GE shall change "starting two weeks prior to sediment-related construction activities" to "starting two weeks prior to any in-water construction activity" .

PCB data laboratory tum-around time (TAT): GE shall reflect in the Work Plan that the PCB TAT for the first two weeks of any in-water construction activity shall be 4 days, and thereafter be 7 days.

EPA notes that the monitoring locations for MON-l and MON-2 in Figure 8-1 do not match the description of these locations on p.82. To assess the overall perfonnance of the silt controls, EPA believes it makes sense to have these two monitoring locations bracket the silt controls; i.e. , MON-l be located just upstream and MON-2 be located just downstream of the silt controls. This would also allow assessment of how much turbidity the various in-water activities are creating. OE shall revise the text and Figure 8-1 accordingly, or notify EPA within seven (7) days of this CAL of OE's desire to discuss this sampling strategy further for inclusion in the revised work plan.

Given that the on-going monthly PCB and TSS monitoring at the outfall to the river will continue (see p.82), EPA assumes that this monthly sampling will be at the same location as the revised MON-210cation (downstream of the last silt curtain), and will therefore overlap/dovetail with the weekly monitoring at MON-2 during capping. OE shall confinn that MON-2 is the location of the monthly sampling.

13. CAL Condition #61: Table 6-3, footnote #2: OE shall change "addressed those regulations in Appendix E" to "addressed those regulations in Appendix L". Note that Footnote 2 of Table 6-3 incorrectly references Appendix E. The correct reference is Appendix L.

14. CAL Condition #63: Appendix B, Figures VRlOl -VRI05, Metes and Bounds: Figures VRIOI through VRI05 depict lines defined as "property lines" along the public streets paralleling the edge of pavement. Note 7 on Figure VRlOl states that such property lines running along public ways represent the limits of the public right-of-way taken by the City or County for the public ways, but that the title to these properties extends to the center line of the public way. While the latter statement may be the case for other public

7

ways in the Silver Lake area, this is not the case along Silver Lake Boulevard (SLB). Since WMECO and GE own properties on both sides of SLB, their ownership covers not only the bank property between SLB and Silver Lake but the entirety of SLB. Note 7 shall be revised to clarify that the "property lines" running along public ways represent the limits of the public right-of-way held by the City for the public ways, but that the title to these properties extends either to the center line of the public way or, for SLB (where the same entities own properties on both sides of the public way), across the entirety of the public way.

15. CAL Condition #70: Appendix D, Technical Drawing 11:

a. The Fourth Street outfall channel is labeled as being excavated to 2.7 feet below grade while Teclmical Drawing 20 and Cross Section 6 show it as being excavated 3 feet below grade. EPA also notes that the graphic depiction of the 3 foot removal area on Technical Drawing 20 is inconsistent with Drawing 20's legend. GE shall revise accordingly.

b. Note # 11: in addition to the issues discussed above in comment #1, the reference here to Drawing 17 shall be changed to Drawing 18A

16. CAL Condition #76: Appendix D, Teclmical Drawing 19B: The Drawing depicts an abandonment detail for outfall 14. It is unclear how GE proposes to fill the end of the open ended pipe with non-shrink grout as depicted in the Profile. GE shall require that a brick and mortar wall be constructed in the end of the cut off pipe and that a flowable non-shrink grout be added behind this wall via an access port cut in the top surface of the pipe in order to fill as much void space of this pipe as practicable behind the brick and mortar wall.

Similarly, since outfall 15 is also a four foot pipe, GE shall revise this plan to address outfall 15 as well with a detail depicting a brick and mortar wall constructed in the pipe end but no flowable grout since this pipe is above the water table. The drawing shall be re-titled "Abandonment detail for SL-OF-14 and -IS" since it is not an "outfall protection detail" and since it will address both outfalls.

EPA also recommends that a note be added to Drawing 19A, Detail 2 to clarify that different outfall plugging methods will likely be required depending on whether the outfall is under water or not.

17. CAL Condition #79: Technical Drawing 24: To avoid confusion in the field, EPA recommends that Detail 3 (both section and elevation) be revised to show the silt fence extending 6 inches below grade to be consistent with Note 1 (which further clarifies that silt fences below the waterline will NOT be so buried).

18. CAL Condition #80: Appendix D, Technical Drawing 25: Detail 2 shows geotextile beneath existing grade, presumably due to a scaling error in the drawing, and this geotextile not extending beyond the stone fill under the adjacent access road. Detail 3 does not depict gcotextile on existing grade as specified in note 2. GE shall redraw these details accordingly.

8

19. CAL Condition #86: Cross Sections: See comment # 1 above: cross-sections I through 70 shall be redesigned as appropriate, and a separate version drawn for cross-sections 16 through 65 to show how these would look immediately upon construction. In addition, EPA has the following general comments:

Transect 6 - The bottom of the excavation profile does not match Technical Drawing 20, Detail 1. EPA believes the depiction in Transect 6 is correct and Drawing 20 needs to be revised. Transect 6 appears to depict the 1.5-foot thick layer of 11" armor stone for outfall protection extending out to the fu ll extent of the annor stone, well beyond the 62 linear feet specified in Technical Drawing 22. If this is in fact GE's intent, Technical Drawing 22 shall be revised accordingly. If this is not GE's intent, Transect 6 shall be revised accordingly.

Transect 20 - The retaining wall on the lake side of the walking path should be depicted.

Transect 21 - the swale within the interior of the shrub-scrub island should be shown on the proposed final grades to be consistent with Technical Drawing #23 . Also, consistent with condition l.b above, voids within the exposed annor stone within this swale shall be filled with topsoil and seeded.

Transect 24 - Based on Technical Drawing 17, Transect 24 should cross an area of the west shore protection system annor near the bank.

Transects 26 and 27 - The 3-foot cut at the edge of pavement should be vertical.

Transect 30 (PEDA outfall) - The concrete outfall structure and current extent of riprap shall be depicted in the existing cross section, as well as the pre-outfall construction edge of water. The temporary riprap shall be removed and the sediment cap shall be extended to this pre-outfall edge of water, not the current edge of water which has resulted from the placement of the temporary riprap outfall protection annor stone.

Transects 57 and 67 - The upland extent of the 3-foot cut should be perpendicular to the slope rather than vertical.

20. CAL Condition #87 : Contractor Submittal Tracking Fonn. GE shall revise as follows

Note 1 shall be updated to the "Revised Final RDIRA Work Plan"

The content of the NAPL Contingency Plan shall also be listed as a component of the SIP under Item 3 as outlined in Section 6.1 of the report.

CAL Condition 23 requires submittal of survey control points, assigned slope correction factors, and required minimum excavation depths to EPA for review prior to excavation. The Tracking F onn shall be revised accordingl y.

9

The fill materials specification requires a submittal for any materials which may be needed to be added to the cap materials to achieve the target TOC percentage. The Tracking Form shall be revised accordingly.

Include a requirement for additional submittals required by condition 9 of this CAL.

The wording of Note 4 shall be revised as follows: "Submittals required by GE, but not included in the SIP, that will be submitted (as described in section 8.2.1 of the Work Plan) under separate cover for EPA review, are shaded."

21. CAL Condition 88. EPA reserves the right to modify or require additional PRSC Plan activities at any time in the future, including during EPA's review of GE's Draft Final Completion Report.

22. CAL Condition #90: Ambient Air Monitoring Program

Table 8-1 shall be revised to include airborne PCBs as well as particulates, and an "X" placed under the "Pre-Construction" column to reflect the pre-construction monitoring described in Appendix M.

Appendix M, Section 10.1 , 2nd paragraph, 2nd to last sentence: "modifications to dust-producing activities" shall be changed to "modifications to dust-producing or airborne PCB­producing activities" to better capture the range of activities that may require corrective action.

23. Planting Plan CAL Condition #3: Note that p.69 of the Work Plan (first sentence) is not quite accurate regarding the description of a single row of taller trees along the eastern end of the lake. For example, this row starts at Station 16+00, not 0+00, and continues south of the end of the walking path towards East Street. The drawings are correct. GE shall correct the text here accordingly, or simply delete "from Station 0+00 to 20+00" from this sentence.

Other comments on planting plan and walking path:

a. Page 69, second paragraph, and Appendix D, Technical Drawings D-I03 and D-502. The Work Plan indicates that "In general, trees and shrubs will be watered upon installation and thereafter as necessary for survival"; however, this requirement is not stated on Drawing D-l 03 or Drawing D-502. GE shall revise accordingly.

b. Drawing D-501 , Detail #5: EPA notes that the specified 24 inch minimum depth of granular backfill under the walking path depicted here is inconsistent with Detail #1 on this drawing, which specifies a minimum of 11 inches. GE shall revise as necessary.

c. Drawing D-502, Details #2 and #3: the note on each of these details regarding placement of erosion control blanket "around all newly installed trees" is inconsistent with note 2 on Detail #1 of this drawing which calls for installing the blanket first "and then carefully cut blanket as

10

necessary to install all required plantings. Do not install plantings and attempt to cut/fit blanket around plants." GE shall revise accordingly.

d. Drawing D-501, Details #2 and #3: the depicted, unlabeled backfill (likely meant to be mulch) above the rootball is inconsistent with the requirement in each of these details that the root flare not be buried. If mulch placement is a requirement, a note shall be added to require that mulch be pulled back from the root flare to avoid long tenn damage to the plant.

Also, to maximize long-term planting success, a requirement should be added to pull or tease so­called "pot-bound" roots from the rootball, and to add starter fertilizer to the planting hole prior to planting. GE shall revise accordingly.

e. Outfall #16, an approximately 3' by 18' asphalt swale, which is to remain in service, will presumably need to be culverted beneath the walking path, but is not so accounted for in the technical drawings. GE shall include this detail accordingly.

24. Section 6.4.1 and Item 3 of the Contractor Submittal Tracking Form. GE shall include the following bullet:

• Immediate suspension of excavated activities in the area of potential discovery.

25. Section 6.6.2.4 - Sediment Removal for Placement of Outfall Protection Measures; Outfall to Housatonic River Area: GE shall revise the Work Plan and Technical Drawings (e.g., Drawings 21 and 24) to require that the sediment areas to be excavated in the Silver Lake outfall area downstream of the proposed sheetpile weir and stop logs (to 14" and 2.2' below existing surface) are excavated as the last in-water construction activity. GE shall direct its remediation contractor to consider removal of this material in the dry by using the stop log system. The SIP shall include a proposal, for EPA approval, describing the means and methods for excavation of these areas.

26. Section 6.8.4 Walking Paths and Benches. Last paragraph. Insert the following before the last sentence: "Fourteen days prior to the proposed re-use of these materials onsite, GE will submit to EPA the analytical data associated with the material and confinnation that placement of the material meets the criteria of Section 3.3 of Attachment B to the POP for re­use, including, but not limited to, continning that:

• The use of such material will allow the response action to achieve the applicable PCB Perfonnance Standards;

• The material will be used only for depths greater than one foot below grade unless the material meets the PCB and non-PCB criteria specified in Section 3.2 of Attachment B to the POP for use of material from off-site sources (as well as comparable geotechnical criteria); and

II

• The evaluation ofVOCs, SVOCs, and metals meets the criteria described in Section 3.2.2. of the POP."

27. Section 8, Project Monitoring. GE shall include the following requirement: "If dust from the work is visibly airborne, the Remediation Contractor will immediately discontinue operations and will implement measures to mitigate windborne migration of particulate matter until there is no further visible airborne dust, either due to the implementation of such measures or a change in conditions."

28. Technical Drawing 19A and 22. For outfalls SL-04 and SL-05, GE shall extend the outfall pipes to the lake side of the bank and provide appropriate outlet protection. GE shall revise the technical drawings as appropriate. GE and EPA shall discuss the appropriate outfall protection and whether or not outfall SL-03 shall be extended. SL-03 is identified as a 4" Water blow-off valve. GE shall meet with the City to determine the purpose of this valve/outfall pipe, the frequency of use, and the anticipated velocities. After this information is known, OE shall design the appropriate outlet protection for EPA's review and approval.

29. GE shall include representatives from MassDOT on their document distribution list. In addition, GE shall coordinate with MassDOT on the design requirements for MassDOT's proposed storm drain discharge from East Street to Silver Lake, including, but not limited to, requirements for new utility lines, materials handling and outfall protection; and to identify which existing outfalls (that is, SL-04, 05 and 06) will be abandoned.

OE shall submit a revised Work Plan within 45 days of the date of this letter.

With respect to any other work plans or submittals related to the Silver Lake Area, nothing in this conditional approval shall be interpreted to supersede the approval, the conditions in a conditional approval, or the disapproval of such GE submittals, unless expressly stated as such by EPA. EPA reserves all of its review and compliance rights under the Consent Decree regarding all submittals, including other submittals related to the Silver Lake Area, including but not limited to, the right to perform andlor require additional sampling or response actions, if necessary, to meet the requirements of the Consent Decree. If there is any conflict between the Performance Standards as stated in the Work Plan and the Performance Standards as stated in the Consent Decree and SOW, the Consent Decree and SOW shall control.

Please do not hesitate to contact me at 617 918 1329 or at dickerson.dave@epa.gov should you have any questions in this regard.

Sincerely,

David Dickerson Project Manager

12

cc: Mike Carroll, GE Dick Gates, GE Rod Mclaren, OE James Bieke, Goodwin Procter Mike Gorski, MassDEP Jane Rothchild, MassDEP John Ziegler, MassDEP Eva Tor, MassDEP Karen Pelto, MassDEP Susan Peterson, crOEP Kenneth Munney, USFWS Ken Finkelstein, NOAA Holly inglis, EPA Tim Conway, EPA Dean Tagiiaferro, EPA Robert Leitch, USACE Mayor James Ruberto, City of Pittsfield Corydon Thurston, PEDA Jim McGrath, City of Pittsfield Deanna RutTer, City of Pittsfield Caleb Mitchell , City of Pittsfield John Burke, WMECO John Tulloch, WMECO Paul Cinquegrano, MassDOT Jack Jemsek, Sovereign Consulting Linda Palmieri, Weston Solutions Public Information Repositories

13