Site LOCUS Figure 1 15 Gardner Falls Road Buckland, Massachusetts

44 Wood Avenue · Mansfield, MA

Site LOCUS

½ Mile Radius

20

SCALE IN FEET

200 40

PLAN

1"= 20'

PZ-02

PZ-03

PZ-01HA15-1

HA15-1A(OW)

HA15-2A(OW)

HA15-2(OW)

HA15-3A(OW)

B-1

WL-DS

HA15-5

HA15-7

HA15-8

HA15-6

HA15-4(OW)

HA16-4(OW)

HA16-3(OW)

HA16-1(OW)

HA16-2

A

A

'

CANAL

S

IT

E

A

C

C

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S

S

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A

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NOTES:

1. BASE PLAN OBTAINED FROM PLAN TITLED "0803046 sht

1-5.dwg", DATED 22 JANUARY 2016.

2. ELEVATIONS ARE IN FEET AND REFERENCE A VERTICAL

DATUM SPECIFIC TO THE GARDNER FALLS

HYDROELECTRIC FACILITY SITE.

3. FULL-TIME ON-SITE TECHNICAL MONITORING OF THE

2015 AND 2016 TEST BORINGS WAS PERFORMED BY

HALEY & ALDRICH, INC.

4. LOCATIONS OF 2015 AND 2016 TEST BORINGS WERE

OBTAINED BY HALEY & ALDRICH BY TAPING DISTANCES

FROM EXISTING SITE FEATURES.

5. PLAN LIMITS OF SINKHOLE TAKEN FROM FIGURE C-2 IN

REPORT TITLED "GARDNER FALLS HYDROELECTRIC

PROJECT, FERC 2334, POWERHOUSE STRUCTURAL

ASSESSMENT," PREPARED BY HDR ENGINEERING, INC.

DATED OCTOBER 2014.

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FIGURE 2

UNIT NO. 2 PENSTOCK REPLACEMENT

GARDNER FALLS HYDROELECTRIC FACILITY

BUCKLAND, MASSACHUSETTS

SITE AND SUBSURFACE

EXPLORATION LOCATION PLAN

SCALE: AS SHOWN

JULY 2016

LEGEND:

HA15-1

DESIGNATION AND APPROXIMATE LOCATION OF TEST BORING

DRILLED BY NEW ENGLAND BORING CONTRACTORS (NEBC) OF

LONDONDERRY, NEW HAMPSHIRE DURING THE PERIOD 12 TO 18 JULY

2016 RELATED TO UNIT NO. 2 PENSTOCK REPLACEMENT PROJECT

DESIGNATION AND APPROXIMATE LOCATION OF TEST BORING

DRILLED BY NEBC OF LONDONDERRY, NEW HAMPSHIRE DURING THE

PERIOD 27 MAY TO 9 JUNE 2015 RELATED TO UPSTREAM HYDRAULIC

CUTOFF PROJECT

DESIGNATION AND APPROXIMATE LOCATION OF TEST BORING

DRILLED BY NEBC FOR HDR IN SEPTEMBER 2014 RELATED TO NO. 2

PENSTOCK SINK HOLE DOWNSTREAM OF UNIT 1 & 2 GATEHOUSE

DESIGNATION AND APPROXIMATE LOCATION OF TEST BORING

DRILLED BY KLEINSCHMIDT ASSOCIATES IN 2011 RELATED TO THE

CANAL WALL REPLACEMENT PROJECT

DESIGNATION AND APPROXIMATE LOCATION OF SLOTTED PVC CASING HUNG

FROM SITE FEATURE TO ALLOW WATER LEVEL MEASUREMENTS IN THE RIVER

DOWNSTREAM OF THE POWERHOUSE

GENERAL PLAN LIMITS OF SINKHOLE PER OCTOBER 2014 REPORT BY HDR. SEE

NOTE 5 BELOW

INDICATES OPEN STANDPIPE PIEZOMETER INSTALLED IN COMPLETED

BOREHOLE

INDICATES OBSERVATION WELL INSTALLED IN COMPLETED BOREHOLE

DESIGNATION, ORIENTATION AND APPROXIMATE LOCATION OF SUBSURFACE

PROFILE

PZ-01

B-1

PZ

OW

WL-DS

HA16-1

A A'

HA15-2

(OW)

12.8'S

EL. 315.8'

BOE

@ 29.0'

HA15-1

(OW)

HA16-1

(OW)

BOE

@ 37.6'

HA16-4

(OW)

HA16-2

BOE

@ 37.6'

21.3'S

EL. 334.3'

15.0'N

EL. 315.8'

5.3'N

EL. 315.1'

12.6'N

EL. 318.8'

BOE

@ 49.0'

182

100/2"

150/6"

62

85

44

15

19

4

5/27/16

78%

0%

87%

80%

97%

88%

123/10"

50/2"

126/6"

127/8"

20

7/19/16

76

135

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20

146/11"

96

61

82

12

55

11

23

11

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7/19/16

7/19/16

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14%

*

87

7/19/16

IN

DS-WL

74%

37%BOE

@ 34.0'

0 10 20

SCALE IN FEET

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FIGURE 3

UNIT NO. 2 PENSTOCK REPLACEMENT

GARDNER FALLS HYDROELECTRIC FACILITY

BUCKLAND, MASSACHUSETTS

SUBSURFACE PROFILE A-A'

SCALE: AS SHOWN

JULY 2016

NOTES:

1. BASE PLAN TAKEN FROM DRAWING TITLED “PLAN AND SECTION GARDNER FALLS POWERHOUSE UNIT NO. 2 TAILRACE

REPAIR PROJECT," DATED 22 JANUARY 2016, PROVIDED BY KLEINSCHMIDT ASSOCIATES.

2. REFER TO FIGURE 2 FOR THE PLAN LOCATION AND ORIENTATION OF THE SUBSURFACE PROFILE; REFER TO

APPENDICES OF REPORT FOR TEST BORING LOGS.

3. THE SUBSURFACE PROFILE DEPICTS THE GENERAL GEOLOGIC CONDITIONS AT THE SITE AND IS BASED ON

INTERPRETATION OF DATA ENCOUNTERED IN THE EXPLORATIONS. LINES REPRESENTING INTERFACES BETWEEN

STRATA ARE BASED ON INTERPOLATION BETWEEN ADJACENT BORINGS. THIS FIGURE SHOWS THE ACTUAL SEQUENCE

OF STRATA ENCOUNTERED AT EACH BORING LOCATION. ACTUAL SOIL CONDITIONS AND INTERFACES BETWEEN

SUBSURFACE EXPLORATIONS MAY VARY SIGNIFICANTLY FROM THOSE INDICATED ON THE PROFILE.

4. ELEVATIONS ARE IN FEET AND REFERENCE A VERTICAL DATUM SPECIFIC TO THE GARDNER FALLS HYDROELECTRIC

FACILITY.

5. EXTENT OF SINKHOLE IS AS SHOWN ON FIGURE C-2 IN REPORT TITLED “GARDNER FALLS HYDROELECTRIC PROJECT,

FERC 2334, POWERHOUSE STRUCTURAL ASSESSMENT”, PREPARED BY HDR ENGINEERING, INC., DATED OCTOBER 2014.

6. INTERPOLATED PHREATIC WATER SURFACE SHOWN IS APPROXIMATE AND WAS ESTIMATED USING RECENT WATER

LEVELS MEASURED IN INSTALLED OBSERVATION WELLS. ACTUAL PHREATIC SURFACE WILL VARY FROM WHAT IS

SHOWN.

31

100/42

LEGENDHA15-1

(OW)

DENOTES BOTTOM OF EXPLORATION AT

APPROXIMATE DEPTH SHOWN

PERCENT RECOVERY/PERCENT ROCK

QUALITY DESIGNATION (RQD)

INTERPRETED GEOLOGIC STRATUM INTERFACE

WATER LEVEL MEASURED IN OBSERVATION WELL ON DATE

SHOWN INTERPOLATED PHREATIC WATER SURFACE FROM

RECENT WATER LEVEL READINGS (SEE NOTE 6)

UNCORRECTED STANDARD PENETRATION TEST

(SPT) N-VALUE (BLOWS PER FOOT)

GROUND SURFACE ELEVATION AT TEST BORING (SEE NOTE 4)

APPROXIMATE PERPENDICULAR OFFSET DISTANCE AND

DIRECTION MEASURED FROM PROFILE LINE

TEST BORING DESIGNATION

(OW - WELL INSTALLED IN COMPLETED BOREHOLES)

12.6'N

EL. 318.8'

7/19/16

BOE

@ 34.0'

Mansfield, MA Amherst, MA Chester, VT www.ohiengineering.com

TABLES

SAMPLE ID RESERVOIR DEWATERDGP

Effluent Limit Units

Solids, Total Suspended 30 mg/l NS 8.4

Chloride mg/l NS 8.22

Chlorine, Total Residual 11 mg/l NS NDpH (H) 6.5-8.3 SU NS 7.8Oil & Grease, Hem-Grav 15 mg/l NS NDChromium, Hexavalent 11.4 µg/l NS ND

Antimony, Total 5.6 µg/l NS NDArsenic, Total 10 µg/l NS NDCadmium, Total 0.2 µg/l NS NDChromium, Total 48.8 µg/l NS NDCopper, Total 5.2 µg/l NS 2.13Iron, Total 1000 µg/l 140 273Lead, Total 1.3 µg/l NS 0.61Mercury, Total 0.9 µg/l NS NDNickel, Total 29 µg/l NS NDSelenium, Total 5 µg/l NS NDSilver, Total 1.2 µg/l NS NDZinc, Total 66.6 µg/l NS ND

ND = Not Detected

Table 1: Groundwater Lab Analysis Summary for DGP Criteria

Gardner Falls Hydroelectric Facility

15 Gardner Falls RoadBuckland, Massachusetts

Daniel O'Connell's Sons, Inc.

Unit No. 2 Tailrace Structure Repair Project

Total Metals

General Chemistry

Anions by Ion Chromatography

General Chemistry

Mansfield, MA Amherst, MA Chester, VT www.ohiengineering.com

APPENDIX A Notice of Intent Form