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STATE OF MAINE

Department of Environmental Protection MAIN OFFICE: RAY BUilDING, HOSPITAl STREET. AUGUSTA

MAll ADDIIEIS: Sllle House Sletlon 17, Auguste. 04333

207·21Q.7e&a JOHN II. McKEIINAN, Jll. DEAN C. IIAIIAIOTT

GOVERNOR COMMISSIONER

October 3, 1988 ocr 1 4 ~~

Hr. Andrew Tovt Central Kaine Power Co. ldhon Drive Auauata, Maine 04336

RE: Feaaibility Study Draft Report and Re l ated Documents for the F. O'Connor Site, Auauata, Maine

Dear Hr. Tovt:

The Deparbaent of !nvironaental Protection baa co.pleted ita review o£ the June 1988 Feaaibility Study Draft Report and Addendu. and the Auauat 5, 1988 naponee to IPA and DIP co.entl. The followiaa are the Depart.eat '• co.aents and are preaented in an order correapondina to the Feaaibility Study Draft Report (Draft PS):

1. Paae 1-13, Site Deacription and Riatory. Provide the date of iacluaion on the IPL;

2. Paae 1-13, Site Conta•ination and Riak Aaaea..ent

le conahtent with the uae of "riak" and "endanaenent" or provide def ini tiona.

Define "abort dhtancu" 11 it relate• to PCI •iaration fro. the 'lWAa

The lA identified riaka fro. inhalation of particulate• froa the aoila aa well aa vapora; reviae the aoil diacuaaion to include thia .

3. Paae 1-20, liota

Include a discuaaion on the availability and reaulta of patholoaical or hiatoloaical data for the biota.

The diecuaaion here ia •i•leadina in that it suaaeata that the FDA action li•it ia protective of aquatic ecoaytte.a. Reviae this to ~ake it clear that the PDA li•it ia only to be uaed for hu.an conau.ption purpoaea and •ay not be protective of aquatic ecoayate.a.

4. Paae 2- 2. Definition and Approach to ARARa

Indicate what the condition• are under which ARARa can be waived .

REGIONAL...,..,. OFFICES • Portland • • Presque Isle •

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5. Page 2-11. Chemica1-apecific ARARa

Claaa GW-A groundwater ia auitabl~ for public drinking water purpoaea without treabaent. Revise tbia discussion to r~flect this

Not all State of Maine drinking water standards and guideline• are baaed on MCLa. The State Department of Ruman Services bas rulea releting to private water auppliea which muat be considered alao.

6. Table• 2-2 and 2-3 1 Chemical and Action Specific ARARa

Include CMR 10-144A, Chapter 233, Appendix C (Rulea Relating to Teeting of Private Water Systems)

Include all of 38 HRSA Chapter 4, Protection and Improvement of Air, Section• 581-611 and the aasociated regulations.

7. Page 3-5. General Remedial Reaponae Objectives

Are Riggs Brook sediments included in these objectivea? If not, include tbea.

8. Paae 3-6. Developaent of Target Clean-up Levela

If a apecific health riak calculated for thi1 aite indicate• that a clean-up level lower than exiatina ARARa-baaed level• or anelyticel detection liait.-re-werrented, the riak-baaed level abould be uaed.

Wby were teraet clean-up levela not developed for riaka of lo-7?

9. Page 3-7 and 3-8. Retionale for Develop.ent of Terget Clean-up Levell

It will beca.e neceaaary to develop a aeparate clean-up level for PCBa in fiab if Riaa• Brook aediaenta are not reaediated and/or PCB-cont..inated aateriala are left on-aite.

Provieiona auet be ..de to aaaure that tbe laaoona will not refill with water and beco.e wetlands aaain, particulerly if the re.ainina eediaenta (aoila) have not been reaediated to levela protective of aquatic life.

10. Paae 3-9 to 3-16. Site-apecific Taraet Clean-up Levela

liak-baaed taraet cleen-up levela ahould have been developed uaing plauaible aaxi.u. expoaurea from Table 5-4 of the !A, aa well aa moat probable expoeurea. The Maine Depertaent of Ru.an Servicea baa adopted the policy of ueing plauaible aaxiaua for calculatina clean-up levell.

If dietary levels of 1 ppa PCBa have been ahown to heve toxic effecta on terrestrial wildlife, 10 ppa ia not an acceptable target clean- up level for protection of the enviroD;;nt . In addition, apeciea closely related to Mink (a aenaitive apeciea) , if not Mink theaaelvea , ar~ very likely to occur at the O'Connor aite. Provide further argu.enta for a clean-up level of 10 ppa.

Extre.e caution aust be uaed in eatiaating riaka poeed to biota baaed on levela which are protective of human health.

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11. Section 4.0. Identification and Screening of Technologies

Elimination of technologies eiaply becauee other technologiee '~ith leeser engineering and implementation complexitiee are b~ing coneidered" is not acceptable at this point (i.e. solvent extraction and dechlorination). Provide detailed analyses of th~se alternative•.

12. Section 5.0 Development and Screening of Remedial Alt~rnativee

Why ie long-term monitoring and maintenance needed for on-site incineration?

Page 5-11 refers to 12 potential remedial alternatives but only 11 are diecuseed. Correct ihia.

An advantage to in-aitu vitrificetion ae oppos~d to on-site vitrification is fever e.iaaione and therefore, leaa public health riek. This •uat be coneidered in the event that on-aile vitrification ie eliminated due to emiaeions problema

Under Alternative SB-2: Minimal No-Action, for Rigge Brook eedimenta - for bow many yeara would fieh ...pling occur?

Why ia long-te~ aonitoring and aaintenance required for in-eitu vitrification and aolidificetion, but not for on-eite vitrification and aolidification?

13. Page 6-10. Ca..unity and State Acceptance

There vae only one public meeting during the II proce11

14. Alternative SC-1: Hini.al No-Action

Why doea thia alternative not include aoil aaaplina?

What levela of conta•inanta reaaining on-eite require the Five-Year Site Review?

15. Alternative SC-2: Site-Capping

Propoeed chana~• in Route 17 ehoulders and drainage ditches may prevent re-routing of eite drainage to the highway drainage eyetea

Ia uee of US EPA PCB Spill Clean-up Policy inetead of a health-baaed riek appropriate in eelectiog action level• for barn floor decontaaination? [Thie comaent applies to all alternativ~• which require barn floor deconte•ination.] Will the barn be diepoeed as ha1ardoua vaate or otherviee? Rae thie been taken into coneideration in chooeing an action level?

A ..aller grid auet be ua~d for confirmation saapling. A 50-foot grid ie not eufficient to locate remaining conta.inated eoil.

11 it viee to place the organic •atter reaulting fr~ vegetation clearing in the cap ar~a where it can decompoee and settle? (Thia pertain• to all alternative• which requir~ veg~tation clearing and cap conetruction.]

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Bov lona i• the propoaed liner auaraoteed for?

Why i• aetala analy•i• excluded froa lona-term aroundvater analyaia? If aetala are left on-aite, there i• the potential for them to eventually aiarate to aroundvater. [Thi• comment alao appliea to other alternative• where metal• reaaio on-aite.)

11 the 200ua/a3 CAA MAAQS atandard for fugitive duat emieaione aufficient for preventina health riak1 from PCB• aaaociated with particulate•?

le a ainale aoil aaaple for the TCLP analyaia eufficient to eneure that treataent atandarda are not exceeded (i.e. Land Ban)?

Thia alternative aay reault in a decreaae of [PCB• in) Ria&• Brook aediaenta, but it would be yeara before it ia aeaaurable

Inatitutional controls will be needed to prevent alteration of drainaae ayateaa, excavation and well drillina in the area once the cap i• in place.

What happeana to the cap after 30 years?

16. Alternative SC-3: On-aite Diapoaal Facility

Who will be reaponaible for diapoaina of leachate froa the tank for years to coae?

Are exiatina aite aoil and aroundvater conditione acceptable for a diapoaal cell?

17. Detailed Analyaia of Maoaaeaent of Miaration Alternative•

Why were clean-up level• for aroundvater not eatabliabed for to-6 riak level? Do oot baae clean-up levela on analytical detection liaita.

18. Alternative MM-1: Miniaal No-Action

Table 7-1 include• the Maine Standard• for Claaaification of Surface Water• •• a potential ARAR yet it i• not included in the diacuaaion on paae 7-5. Reviae tbia.

Thi• alternative ia ~ likely to be acceptable to the co.aunity aod atate.

19. Alternative MM-3 : Groundwater Extraction and On-aite Treataeot with Activated Carbon Abaorption

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The hydrogeologic inforaation collected durin& the RI ie not eufficient to atate that the aroundwater behave• ae a eingle, complex eyetn. A detailed pump and treat propoeal cannot be developed until the data gapa have been adequately addreeeed. The hydrogeologic characterietice and propertiee (pe~eability, hydraulic conductivity, etc.) of each of the etratigraphic unite at the eite, ae well ae the hydroloaic connection between the various unite muet be determined. The bedrock hydrogeologic eyetem in particular need• additional etudy. The photogrammetric and outcrop analysis reeulte muat be integrated with aite-epecific hydrologic and aeologic data, and the relative i.portance of the different fractures to the eite hydrology must be determined before an effective pump and treat ayetem involving bedrock can be deeigned.

The extent of the plume and ita rate of aigration auet be determined before a pump and treat eyetem can be deeianed. The one additional pair of aonitoring vella propoeed (MW-107A) and 107-1) ia not eufficient to accompliah thie. Several aore well cluetera are needed to define the lateral, vertical and longitudinal boundariea of the plume. It ia crucial that the photogr...etric and outcrop atudy reeulta be coebined with the information derived froa exiating bedrock velle to optiai&e the location• of the new bedrock velle.

There ie not enough hydroaeologic and water quality data currently available to calculate quantitative concentration• in groundwater under "bot epote" with any dearee of certainty. Moreover, 200,000 ua/ka (the hiaheet concentration• actually found in eoil on-eite) rather than 38,000 ua/kg PCie ahould have been uaed in the leaching potential calculationa.

The effectiveneee of the carbon filter• to r ..ove tbe array of cont..inante (not juet the cont ..inante of concern) auet be dnonatrated.

Do ve know for certain there are droplets of oil in the aroundwater? Bow doea thia affect the treataent ayete.?

Why vae epray irrigation choaen over groundwater reinjection? Will the ayat.. be ehut down all winter? What are the effect• of epray irriaating the eite-epecific eoila and vegetation? There are etate AlAI• which apply to diachargea of water by epray irriaation (38 MRSA Section 413(l)(A).

The propoeed monitoring plan is not aufficient. An array of aonitoring vella ia needed ae oppoeed to only a couple of dovnaradient velle. The frequency of ...pling auet be increaaed for the firet 2 year• to adequately •••e•• the eeaeonal effect• on the influent and effluent concentration•.

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20. Section 8.0 Co.parative Analyaia and Su.aary of Alternative•

Do not aake aaeuaptioae •• to what ••Y be acceptable to the State. Off-eite diepoeal ia not acceptable •i•ply becauee it ie diepoeed of out of the atate. ·

The applicability of Land Jan hae not been clarified for this eite and ita cont..inaate.

Where i• it etated that •olidificatioa and vitrification are per.aneat aolutiona!

Solidification doea not •eet C!ICLA perference for reduction of toxicity and voluae.

Colt-effective ehould not be aiven preference over long-tera protection of public health.

The eenaitivity analyaia provided in tbia aection ia not adequate. Provide eeti.. tea of coat, voluae of aoil to be treated apd ti•e for co.pletion of treabaeat ueina 1,5 6 10 ppa PCI taraet clean-up level• for the followina alternativea:

Vitrification Solidification Solvent Extraction Incineration Dechlorination

In addition to theee co.aente, tbe Deparbaeat hae eerioua reeervatione about the reca..ended taraet clean-up level• for aoil• and the li•ited nuaber of arouadwater coat..inante beina coaeidered for clean-up. The•• ieeuee will be diecueaed further with !PA and CMP in the followina weeka.

s(J~~l~Ao- A. t<-J..UA4 ~~--;:--lUHRS, !8 III Divieion of Licenaiaa 6 !aforc..ent Bureau of Oil 6 Bazardoua Material• Control

CJit:ea / ,.

cc: Steve Serian, IPA ~