COMMITMEN T & INTEGRIT

Y DRIVE RESULT

S 4 1 Hutchins Driv e T 800.426.426 2 Portland , Main

e 0410 2 T 207.774.211 2 www.woodardcurran.com F 207.774.663 5

Ma y3,201 3 Ro y Koster, P.E . Manager- EH&

S Complianc

e Central Main

e PowerCompan

y 8 3 Edison Driv

e Augusta , M

E 0433 0 

### Superfund Records Center SITE: O'

(Onr\Or BREAK: TZ

~ 

## OTHER: ZJiT^To i SDM S DocI D 55256 0

Re : O'ConnorCompan y Superfund Site , Augusta , Main e Observatio n o

f Disturbe d Soi l Conditio n an

d Recommendation

s Dea rMr . Koster, A s yo u requested , I accompanie d you o n a visi t t

o th e O'ConnorCompan

y Superfun d site , Apri l 30 , 2013 , t o examine a

n unusual disturbanc

e o f surficia l soil . The disturbanc e firs t observe d durin g a recen

t routin e inspectio n b

yCentra l Main

e Powerca

n b e broadl y characterize

d a s hole s i n th e ground . The presenc e o f hole s raise d questio n abou

t cause , suc

h a s erosion , settlement , o ranimals . The are a exhibitin g th e unusual soi l disturbanc e is perhap

s 50 0 squar e fee t o f grasse d fiel d positione

d immediatel y downhil l o

f th e Designate

d Area' s easter

n margin . Withi n th e disturbe d are a ar e multipl e smal l hole s bes t describe d a s tunnels . Som

e tunnel s ar

e jus t beneat h th e dea d vegetatio n fro m las

t growin g season whil e othe rtunnel s ar e a t shallo w dept h i n th e soil . A

s show n i n th e attache

d photos , i t wa s possibl e t

o prob e int o th e tunnel s wit h a metal measuring tape . A t entrance s t o a fe w tunnel s wer

e large rvoids on th e orde ro

f 6 t o 8 inche s i n width , heigh

t an d depth . Upo n seein g th e situatio n an

d subsequentl

y sharin g photographi c informatio n wit h a colleagu e w e hav e conclude d th e soi l disturbanc

e wa s cause d b yanimals , likely vole

s o rsimila rsmal l rodents . Woodar d & Curran is currentl

y involve d wit h a landfil l sit

e i n Massachusett

s wher e a vegetate

d fina l cove ri s exhibitin g a nearl

y identica l occurrence . There , vole s wer e th e confirme

d cause . The singl e differenc e a t th e O'Connorsit

e i s th e large hole

s nearth e tunne l entrances . W e speculat e th e large rhole

s ar e th e result o f coyote s o ranothe ranimal diggin g fo ra meal . Understandin g th e O'Connorsite' s remed y include s a clean protectiv

e soi l laye rcoverin g contaminate d soil ; i t i s desirabl e t

o maintai n th e integrit

y o f th e coverin g soils . Althoug h th e vol e tunnel s w e observe d ar e outsid e th e site' s Designate d Are a wher e contaminate

d soil s persist , i t i s possibl e tha t th e animals wil l expand thei rhabitatio n t o othe rportion s o

f th e site , includin g th e Designate d Area . Therefore , i t is desirabl e t o eradicat e th e vole s befor e th e colon

y expand s and th e Designate

d Are a i s als o affected . The existin g coyot

e hole s shoul d b e fille d wit h soi l t

o eliminat e trippin g hazards and reduc e possibilit y o f erosion . The vol e tunnel s ca n b e lef t as-i s t o recove rthroug h collaps

e o rfil l wit h vegetatio n roots . I n conclusion , Woodar

d & Curran recommend

s tha t CM P tak e a n activ e approac h t o remov e th e vol e colony . A professiona l exterminato rshoul d b e contacte d fo radditiona l guidanc

e and mad e awar e othe r wildlif e i s evidentl

y present . Maintai n th e frequenc y o f sit e inspections ; bein g cognizan t th e vol e tunnel s ar e mos t visibl e whe

n th e gras s is firs t emergin g i n earl

y spring . N

o additiona l cours

e o f actio n beyond th e routin e inspections an

d maintenanc

e appear s necessary .

## WOODAR

D &CURRA N W

e hop e you fin d th e opinion s usefu l fo rprovidin g a solutio n t o a potentia l problem . I f ther e ar e furthe r question s o rnee

d fo rassistance , pleas

e contac t m e a t 1-800-426-426

2 o remai l pporada(5)woodardcurran.com . Than k you fo rth e opportunit

y t o assis t CM P wit h thi s issue . Sincerely , WOODAR D & CURRA

N INC . Pau l Porada , P.E . Vic e Presiden

t PJ P 226630.1 3 Enclosures : Photo

s cc : Terr

y Connelly , U

S EP A Claudi a Sait , Maine DE P

CM P (226630

) 2013.05.0 3 Letter.Doc

x 2 Ma y 3,201 3Affecte d Area , Boundar

y Highlighte

d

Remnant s o f anima l burro wi n soi l surfac

e and beneat

h vegetation .

CM P (226630

) 2013.05.0 3 Letter.Doc

x 3 Ma y 3,201 3CM P (226630 ) 2013.05.0 3 Letter.Doc

x 4 Ma y 3,201 3Large r siz e hol e du g a t entranc e t o a burrow

. Roughl y hemispherica l i n shape , 6 t o 8 inche s diameter

. Not e excavate d soi l o n groun d betwee n hol e an d boots .

CM P (226630

) 2013.05.0 3 Letter.Doc

x 5 Ma y 3,201 3