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U, S. ENVIRONMENTAL PROTECTION AGENCY REGION I

J.F. KENNEDY FEDERAL BUILDING, BOSTON, MASSACHUSETTS 02203-2211

DATE: January 9, 1991

SUBJ: Technical Directive Heaorandu11, Phase lA RI/FS Picillo Far• aite, Coventry, RI .

FROM: Anna P. Krasko~EPA Remedial Project Ml!lnaqer

TOo Robert N. La111be , ADL Project Manager

The purpose ot thia memorandum b to transmit to you EPA couents on the Draft Technical Directive Memorandua, Phase lA RI/FS, Voluaee I and II, dated November 28, 1990, and Volume III, dated Deceaber 14, tor the Work Assignme nt 01-lLDl tor the above Site.

In addition to epecitic comments on the report, EPA also has ao111e additional questions related to the s ubsequent phases of the field inveatiqation. Although some ot these concerns may ba better addressed in the Work Plan tor the Phases 18 and II, they should be dbcu..ed before hand to minbize any •i•underatandinga.

Becauae this Technical Directive Memorandum is an interim deliverable under this work assignment, and because ot the overall good quality ot the report, EPA approves this report with a condition that the following co111111enta will be addressed by the ADL in a written •e•orandum to be submitted to the EPA within 2 weeka ot a receipt ot the comments. EPA expects ADL to incorporate the required changes in the subsequent deliverables under thia work a..ign•ent .

ADL should sub•it to the EPA three (J) unbound copies ot the Volu•• I, and two (2) unbound copies ot each, Volume II and III.

Voltllle I

1. Table ot Contents Host ot the pages are not numbered in accordance with their reference in the Table ot Contents, which makes it ditticult to lind any given section in the text .

2. Section No.1, Page 2 ot 11. Site History The PRPs signed the consent decree and performed the remedial action in 1988 not 1989.

The 1985 ROD called tor construction ot a RCRA landfill, which would include leachate collection and groundwater monitoring, thus, it is incorrec t to state that the ROD called tor "a no action management ot migration ot contaminated ground and surface water" .

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,-..., J. Section No . 1, Page 2 of 11. Previous Investigations Phenol should be included as one of the contaainant• at the Site.

4 . Figure 1.1 Topographical Location Map Add expl anation to that aap, or re•ove word "explanation fro• the tigun.

5 . Figure 1 .2 study Area Locus Map (and subsequent ••P• and text)

Aa waa diacuaaed with Bob Lallbe previously, the area vest of the houses s hould be called "solid waste dut~p" or "solid waste diapoaal area", not "landfill". The ten "landfill" ia i nappropriate for thia dte dnce it does not fit the traditional description of a uch . All r eferences to that area on the aapa , tables , and t ext ahould be chanqed.

6. Section No. 2, Page 1 of :u. Elevation survey Plate nullber h miaaing in the reference to the topographic baae.... 7. Section No. 2, Page 9 ot 26 Residential Well Inventory and

Saaplinq ADL should discuss and include a general location map and a suaaary table for r ..idential welb ..mpled by the Rhode Island Oepartaent ot Health for the last 11 yeara. since the report lacke any discussion ot the historical sampling results, AOL'• s tateaent that "disposal site constituents may be contaminating so.. residential well•" ia unsubstantiated. The RIOOH data should be incorporated with the samplinq results troa thtt thirteen residential walls saapled by ADL to detenina the •igration pattern ot the contaainanta .

8. · Section No. 2, Page 13 ot 26. Monitoring Well Inventory, Develop.ent, and sa•pling

'l'ha data s hows that all the equipment blanks contained high levels ot •ethylene chloride. The decontamination procedure states that hexane was used to clean the equipment. There is no explanation ot the origins ot the aethylene chloride. Even throuqh it did not affect the sa111ples, the problem needs to be corrected tor future aamplinq.

The type ot bailer which the samples were collected in needs to be added to the description ot the sampling procedures .

9. Figure 2.1 Observation tro• EPIC In order to make the map more ·clear, add outlines ot the areas 1 through 9, similar to ADL' s Fiqure 2.2.

10. Piqure 2.5 Residential Well Sample Location Show outline ot the unnamed swamp and great cedar swamp . Show drainage connection between the lower beaver dam and Whitford Pond, and the upper beaver dam and Unnamed swamp.

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~ ll. Figure 2.6 Developed and Sa•pled Monitoring Wells Add a legend, explaining the difference between wells shown as dark and light circular a}'Jlbola. Add na!lea of all water bodies shown, add outline of the Unnaaed swamp, show drainage pattern, and designate dhpoaal area •• such.

12. Section No . J, Page 2 of 45. Surface Water Hydrology Throu9hout thla Section, ADL uaaa ten "for~~~ar landfill" and "historic landfill" in reference to the former disposal area , To be conaiatent with the res t of the report, ADL should refer to this area aa "disposal atea".

13. Piqure 3.1 Surface Water/Sedi•ent Sa•pling Location In the future reports ADL should deaignate separately surface water va. aedi•ent aa•pling locations, since in ao•e locations, such aa SW 20, 21, and 22, it is feasible only to collect sedi11ent samples.

14 . Figure 3. 8 Doaain Analyaia ot Joint Orientation Add outlines of the awampa and s how drainage pattern.

1 5. Figure 3.11 Seiaaic Retrac tion and VLP Traverses and Figure 3 . 13 water Level Contour• .,

Add a legend explaining different aarapling locations , add SW 14 thru 22, add naaea and outlines of all water bodies and drainage -pattern, name di s posa l area as a uc h . n 16. Section No. 4, Page 3 of 26 Soila = Add a tigure s howing location ot aamplea done by RIDEM i n 1988 (Table 4 .3) =U"' 17. Section No. 4, page 5 of 26 Monitoring wells ADL should check the data for the following compounds in each of the walla identified :

MW-45 1, 1, !-trichloroethane (1000) concentration is different than described in sample AQ768 (2600) ; explain.

KW-44 1, 1, 1-trichloroethane (2600} concentration ia ditferent than described in sample AQ769 (1000); explain.

KW-17 Explain, how the TVO of 2,215 was calculated. The greatest concentration f ound in this well was 830 according to sample AS007.

MW-06 Explain, how the TVO of 320 wa s calculated and why the concentration of 1,1, 1-trichloroethane a nd toluene are different than those described i n sample AS02J.

18 . Section No . 4, Page 6 of 26 Monitori ng We lls While it is true that pas t chemica l data has not been fully validated , ita evaluation is still significant. The lack of seasonal data may be cause for more data limitation than the

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-val !dation.

19. Section No . 4, Page 7 of 26 surface water a nd Sedieent Location of historical surface water aa11pling is aiasing on Figure 1.2, deapit. the reference to thia Fiqure in the text. It 111ay be acre convenient to show these locations on the Figure l.l, surface Water/ Sedi•ent Saapling Locations.

20 . Piqure 4 ,3 EPA/RIDEM Post Soil Reaoval Sa11pling Result. The date of those auaplea ia incorrect, change 1979 to 19811.

:n. Figure 4 .1 Mag netic Anoaaly Locations Figure 4 . 2 Soi l Caa Anoaaliea

Add outline of the areas 1 through 9, in order to better show which areas were actually covered vith magnetic survey and soil gas survey.

22. Piqure 4 . 3 through Fiqure 4. 7 Change the Bar Scale to r e tlect the correct scale lin. •200ft (currently it s hows a scale Un.•lOOft .) .

In order to 11ake interpretation of these Figures more straightforward, use different symbols for wells s ampled and welh not aa11pled (for example, u se shaded and non-shaded circles) and add a legend. Although ADL used annotations tor sa11pled vella, so•eti11es it is not clear which wells are annotated and which are not .

23. Section Ko. 5, Suaaary and Conclusions The major downfall of this report h the insufticient discussion of the conclusions based on the evidence collected during Phase lA RI/FS. Phase lA data should serve as a basis for hypotheses tor contanination patterns , 1. e. new sources vs. plume 11iqration, and the additional data acquisition proqram should be designed to prove these hypotheses. For example, ADL should discuss suspected patterns of contamination in North Field and design the sampling program to fully characterize that contaaination. In addition , ADL should discuss solutions to the anticipated difficulties and special problems in the tield, such as li•ited access to some areas, poeeible presence of DNAPL on the Site, and disposal of wastes generated during tleld investigation.

24 . Section No. 5, Page 2 of 18 Data Gaps and Limitations The sentence "the primary l..1m.i.t.l..t. of existing data is directly ~ to its age" should be clarified.

25. Section No. 5, 2age 3 of 18 Reco11.111e ndations for Additional Data Acquisition

Prior to conducting any sampling off-site, ADL s hould check the access records to verify that EPA has an access agreement with the property owners.

In addition to discussing source c haracterization, plume

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delineation, risk assessment, and treatability studies, ADL s hould • ••••• data gaps for fate and transport 11echanialls of the conta•inanta in the aubaurface.

At a •ini•um, the folloving phyaicaljche• i cal properties would have to be acquired for each contaminant of concern: aolacular for.ula, aolubility in vater, Henry•a Law constant., octanoljwater distribution coefficient, andjor aoUjvater distribution coefficient, apaciation, and chemical reaction rates, ADL a l ae should be aura to get the organic carbon content of the aolh. We alao a nticipAte batch and colunn t ..t a to obtain aoil partition coefticient.

26. Section No. 5, Page J of 18 Source Characterization How will borings near probable 1-hcibla phase be donajcomplatad? ADL has to diacuaa procedures and the number ot saaplea.

Haa ADL considered to do deeper and fewer borings, particularly in the source areae? Deep borings i n the source a r eaa may need a t a • iniaua aome adaixed be nton i t e. A concern i• that drilling in the backtillad t renches will mean going through a lot of clean fill (except recontaminati on from the ground wate r) . AOL shoul d consider aore borings completed s lightly ott the trenc hes a nd out side the fence to see if we can find evidence of later a l tingaring of the 1-iacible phases (s ee Ebasco Work Plan) . ADL s hould also consider a possibility that solvents that were disposed of could have he lped lD.Obilize the PCBS. ADL s hould keepthia joint goal in aind when installing vella along the North, South and West .aides it the fence. Doing s o would als o enable the borings to be used as part of a couple wi th an exi s ting well .

Place a piezo•eter in aost of the s oil borings. Additional head data will ease contaainant and transport interpretations. If •o•• borings are deep, piezometers will provide r e lative ly inexpensive data that b in otherwise short supply, i. e . how d eep flow ia different fro• s ha llow and how vertical flow v a ries. ADL should co-ant on an idea of placing up t o t!!Q piezomet ers (1\ inch each) i n the same boring with bentonite above and be l ow t he s and pack for the piezometer's s creens.

27. Section No. 5, Page 3 of 18 Source Characterization lind Table 5.1 (2}.

Under trenching activities, ADL proposes f ive tre nc hes, however, Figure 5.2 shows s ix trenches , the additiona l trench being l ocated at the aagnetic anomaly of 700 g alllJIIas j ust west of the aan-made pond; expl a i n this discrepancy.

28 . Section No. 5, Page 3 o f 18 Source Charact erization and Figure 5 .1 Disposal Area Soil Borings

What was t he r ati onal for eliminating surface/shallow soil samples (as was proposed in the Ebasco Work Plan) inside the fence area and just outs ide the fence? Additional surface soil samples should be included in Area 8 as ~o~ell as with any othe r

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borlnqa a nd tre nches. We need th••• sampl es t or the riak • ••• ••••nt purpoaea.

29 , section No. 5, Page J o f 18 source Characterization a nd Tabl e 5 . 2 Proposed Saap la Location Rationa l

Soil aa•ple locations for the aolid wa a t e du11p a r e 58- AO to SB-AW not SB-AO to 58-AW .

30 , Section No, 5, Page 4 of 18 Source Charac terization Ooea ADL antic ipate ua ing of a t ainleaa a t ee l ac r eena, at l eaa t in ao•• of the wa lla?

Geophyaica on s hallow (circa 20 f oot) bedrock is not warranted, eapechlly if borings are cored.

ll. Sect i on No. 5 , Page 4 of 18 Pl uaa Delineation ADL shou ld pay aore attention to clustering wella.

ADL should antic i pat e three-we ll c lua t er if more t ha n JO teet of s atur ated ove rburden and/ or •ultiple zonea ot' i nterest are encountered ( aee Ebaaco Work Plan) .

AOL ahould anticipa t e to goo 20 teet into rock att a r r e fus al . However, our goal ia to install scre ena in the wea thered bedrock, ao aa to have water and not to •isa sinking plume a t the overburden/bedrock interface.

The bedrock wells next to source areas should be continuously cored, for vella further froa the source areas consider aa•pling . at five foot centers. Aaauaing that the tre nches were filled with clean fill, continuous apoona are not nece s sary through the backfill material above the water table . Below the water table and everywhere elae continuous spoons are needed, because of the concern of recontaaination at the fluctuating water table and below .

Uae soil borings for wells whenever possible. The report 1s not clear about which wells vould be located in soil borings .

So•• wells should be bored to bedrock even through they will be finished a a overburden walla. The concern is that previous studies may have incorrectly inferred bedrock .- Proposed wa lla I and P are examples of this conunent. The r esults of the s eisl'llic survey should clarify whether this concern i a warranted .

Ia there a NE-SW trending lo"' through the fenced-in a r ea ? A aebaic line running eas t to wes t , i iUIIediate ly south o f the fenced area v ould he lp u s to identify this tre nd. We can also locate borings/monitoring walla to address th is. The results of the seis mic l i ne should be used to determ.ine fi nal l ocat ion of we ll s.

32, Sect ion No. 5, Page 5 of 18 Ri sk Asses s ment As part of the data needs t'or the Human Hea l th Ri s k Assessment,

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ADL should conduct an inventory of public water supply wells in t he vicinity of the Site and a 1 ikelihood of thea being impacted by the oft-site aigration ot contaaina.nta. Based on a discussion between David Chin, Water Division, and an official with the Kent County water Authority (KCWA), the :KCWA has two or three product ion we lla in Coventry, but all ot thea are located at l east several aile• aaat ot the Picillo Site. There appear to be several aaaller couunity water ayata•• that serve housing developaents and nursing hoaea that are located in Coventry. Th h i n tonati on should be continaed.

In conducting future ..,ork on the Site, please note, that Rhode Island OEM is in the process ot proaulgating regulations tor their ground ..,ater cla..itication and standards aystea. This should be completed by aid-1991. Part ot the Picillo Pan Site ( f enced-in d hpoaal area) is proposed as GB - i.e. ground water resources ..,hich aay not be suitable tor public or private d rinking ..,ate r wi thout treatment due to known or presumed degradation. The reaaining part o f the Site (approxi1oate extent ot the groundwate r contaaination) will be d..ignated CA-NA (nonattainaent area) - L a. g r ound ..,ater resour ces c lassified aa GA which do not a eat the CA s t a nda rd• under curre nt conditions; the goal i a t o res t or e thia ground water to drinking wa t er quality. The surrounding area ia c lassified CA - i. e. drinking water quality resources. More information on the State' s ground water classification ayatea can be obtained from Ernie Panciera , RIDEM'a Environaental Planner, at 401- 277-2234.

Thera are no apparent Wellhead Protection Areas in the immediate vicinity or the Site.

JJ. Section No. !5, Page 5 of 18 Risk Assessaent and Table 5.2 Proposed Sallple Location Rational

ADL should include rationale for location of sediment and surface water •••plea in the Table 5.2, sinc e this intonation vas not included i n the Work Plan for the Ecological Risk Assessment, dated Novaaber 12, 1990. Since Table 5.1 Data Gaps l!llnd Recouendationa for Additional Data Acquisition identifies insufficie nt aediaent and aurtace water data, samplingintonation tor those 11edia should be added to the Table 5. 2 . The dbcuaaion on location of the sl!llmples should specify rational for deviations from the EBASCO Work Plan.

34 . Figure 5 . 2 Proposed Soil Boring and Trench Locations Prom the result• of Phase 1A inves tigation of the are a 8, it appears that we may need more s urface s oil samples t o d e f i ne contamination of this fie l d.

35 . Table 5.2 Propos ed Sample Location Rational and Fi gure 5.3 Propos ed Monitoring Well a nd Sei s mic Survey Locations

Comments on specific wells: * MW- I and MW-F - Consider placing t hese wells in the soil

borings.

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MW-L - Shallow well aay not be needed given the nuaber of ~ ahallov \olella north of the tence .

HW-M - Baaed on resul ta of the aeiaaic survey, aay need to aove thb deep well further west to pick up potential valley or Northeast trench, May need nev deep well in the Northwest trench (aee co..ent tor MW-H. HW-K - Condder placing thb vall in a soil boring near Weat trench. May need additional bedrock well near Wast trench to pair up with either existing or new overburden walla . Use one ot the soil borings, probably SBS, HW-N and MW-0 - Consider placing these vella in the soil borings in South/Slit trench area. Results of the aeiaaic survey aay help to detine their find location. MW-Z and KW-AB - It th• southern ..Isdc line indicate a SW/NE valley, we aay want to couple these \olalla as overburden/bedrock. MW- AA - Given i•portance of the ground water divide, ve may need to pair up thb vall with an additional overburden well. MW-G and KW-H - Results ot the ••h•ic survey may he lp to finalize location of these wells. KW-B and HW-C - Sa•e COIUIIent a s tor KW-G and MW-H .

36. PiC)Ure 5.3 Proposed Monitoring Well and Seia•ic Survey Locations ,

Na•• all water bocH ea, add outline of the swamps , label dis posal area as such.

37. In the future deliverable• ADL s hould use numbers not letters tor designation of the •••plea (soils and groundwater). Nullbering of the •onltoring we lls should be continuous with the existing vells.

38. Differentiating conta•inant concentration with depth will also be use ful. In future reports this should be done on the croaa-sections. All plan view figures s hould differentiate wells according to depth, especially it cheaical data is shown.

39. ADL should map plan view of bedrock surface. The additional aebaic and well data will help define how bedrock has controlled contaminant dis tribution, since we suspect presence ot a dense immiscible phase liquids . currently, given the cobblyf boulderly overburden, the bedrock surface is probably not as well known as it will have to be .

40 . ADL should include topoqraphical base maps at the same scal es as other plan view maps in the report, or, on some maps, add tope as the background to most of the maps.

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41. ADL should discuss handling ot w.sstes generated during RI. For aonitoring we ll i nst alat ions, AOL should plan on drum~~ing corings with TVO greater than 1 ppa.

Vo luae III

42 . Plate 1 Topographic Base Map (1.: 2 , 400) Show outline o! the d iapoaal area .

Sy.boh t or s urface wat er;sedhent sa11pling points 14 t h ru 22 s hould be cons i stent with the r est of the first 13 points.

The Gr eene Coapany naae i s 11hspelled.

The l ege nd s hould i dentity surf ace water/sediment sa111pling point not "'surface wa t er point".

43. Plate 2 Topographic Base Map (1:24 ,000) It ia uncl ear what 1a t he pu rpose ot showing prope rty l e ta in a great detail eut of the Victory Highway, halt a mile tram the Picillo Site, while providing no i ndication whe r e the Picillo Parra property i t selt 1a locat ed on t his map.

44 . Plate 3 Surface Wate r Hydrology Thie Plate ehould have a title on it. Are the number s on the mapindicate ea•ple locations? Labe l dis pos al are a a s s uch . This up with intonation euch as s urface water divide , seeps , s wamps,and vatar bodies would be useful to have in the ~future dalivarablea for the Ecological Risk Assessment .

4 5 . Plata 4 Geoloqy Map The scala and contour inte rval indicated on the map ar e incorrect. Since this aap is a blow-up of the COE map, ADL ehould adjust the bar acale accordingly. Also, the c ontour interval on this •ap are every 5 f eet not 2 fee t . The not e on the • ap "thie ..p co•plies with nationa l 111ap a ccuracy s t a ndards tor two contour interval •apping" ia not appropriate .

46. Plate 5 Wate r l evel contours , September 1990 a nd Plate 6 Pote nti al a nd ~own Source Are as

ADL base aaps are at the large r sca l e than COE map ( Pl a t e 3) , however, the COE map has 111uch mor e t opographic features , i.e. tree lines , stone walla, water bodi e s and ditches . I t i s a l so has a h igher graphic qua lity, i.e. heavi e r contour lines every 25 t eet , different symbol s for different t opographic featur es, a good legend , etc. This h i gh quality ot the COE maps makes t hem eas ier t o r ead and use . If ADL can not produce s imilar maps on t heir ays t em, t hey shoul d use blow-ups of COE maps as a bas e, and t race new i n formation froa the ir plots onto these maps f or the final aubmittions t o the EPA.

On plate 5 t he l eg end incorrectly s t a t es t hat t he contour inte rval on the map is 10 tee t, the actual contour i nterval is 5 feet . What is the cont our interva l on Plate 67