## DES Waste Management Division 29 Hazen Drive; PO Box 95

Concord, NH 03302-0095

2012 Annual Summary Report Groundwater Monitoring Program Town Garage/Radio Beacon Site

Londonderry, New Hampshire
NHDES Site #: 198509001 Project Type: Superfund (CERCLA) Project Number: 0003569

Prepared For: Town of Londonderry, New Hampshire c/o Sherilyn B. Young, Esq. Rath, Young and Pignatelli, P.A. PO Box 1500 Concord, NH 03302-1500

Prepared By: Sanborn, Head & Associates, Inc. 20 Foundry Street Concord, NH 03301 Phone Number: (603) 229-1900 Contact Name: Timothy M. White, P.G. Contact Email: twhite@sanbornhead.com

Date of Report: January 16, 2013

# Groundwater Monitoring Report Cover Sheet

Site Name: Town Garage/Radio Beacon Site Town: Londonderry Permit #: GWP-198509001-L-003 Type of Submittal ( Check all that apply ) Periodic Summary Report ( year ): 2012 Data Submittal ( month and year per Condition #7 of Permit ): November 2012

Check each box where the answer to any of the following questions is “YES” Sampling Results During the most recent monitoring event, were any new compounds detected at any sampling point? Well/Compound: Are there any detections of cont amination in drinking water th at is untreated prior to use? Well/Compound: Do compounds detected exceed AGQS? Was free product detected for the first time in any monitoring point? Surface Water ( visible sheen ) Groundwater ( 1/8” or greater thickness) Location/Thickness:
Contaminant Trends Do sampling results show an increasing concentration trend in any source area monitoring well? Well/Compound: Do sampling results indicate an AGQS vi olation in any of the GMZ boundary wells? Well/Compound: Recommendations Does the report include any reco mmendations requiring DES action? ( Do not check this box if the only recommendation is to c ontinue with existing permit conditions. ) The November 2012 sampling event is the third consecutive sampling event at MW-2R with no exceedances of groundwa ter cleanup standards. As such, we propose to meet with USEPA and NHDES to discuss the proposed approach for the site closeout process. This form is to be completed for groundwater monito ring data submittals and periodic summary reports submitted to the New Hampshire Department of En vironmental Services Waste Management Division.

# 2012 Annual Summary Report Groundwater Monitoring Program Town Garage/Radio Beacon Site Londonderry, New Hampshire NHDES Site No. 198509001
Prepared for Town of Londonderry, New Hampshire File No. 2049.04

January 2013

### 20 Foundry Street Concord, NH 03301



## Sherilyn B. Young, Esq. Rath, Young and Pignatelli, P.A. P.O. Box 1500 Concord, NH 03302-1500 January 16, 2013 File No. 2049.04

Re: 2012 Annual Summary Report – Groundwater Monitoring Program Town Garage/Radio Beacon Site Londonderry, New Hampshire NHDES Site No. 198509001 Dear Sherry: On behalf of the Town of Londonderry (Town), Sanborn, Head & As sociates, Inc. (Sanborn Head) completed a groundwater quality monitoring event at the T own Garage/Radio Beacon Site (site) in November 2012. In addition to the permit- required annual monitoring activities (collection of a volatile organic compound [VOC] gro undwater sample at monitoring well MW-2R), similar to 2011 sampling, groundwater s amples were collected from MW-2R, MW-6D-2, and MW-6D-4 1,2 

## and analyzed for VOCs, 1,4-dioxane, and total (unfiltered) metals (i.e., antimony, arsenic, barium, beryllium , and chromium). Groundwater Management Permit (GMP) No. GWP-198509001-L-003 (ef fective November 26, 2007) was issued by the New Hampshire Department of Environ mental Services (NHDES) to the Town for the site . This report is subject to the limitations in Attachment A.


## GROUNDWATER SAMPLING AND ANALYSIS Groundwater samples we re collected from monitoring well MW-2R, and multi-level monitoring well MW-6D (2 and 4 intervals) on November 19, 2012 (refer to Figure 1 for the Monitoring Well Location Pla n). Prior to purging/sampling m onitoring well MW-2R, the groundwater level in the well was measured with an electronic w ater level meter. The groundwater sample from monitori ng well MW-2R was collected usi ng a portable submersible bladder pump. Low-fl ow sampling techniques were use d, as described in Sanborn Head’s December 2009 Quality Assurance Project Plan (QA PP).

1 

### Monitoring well location MW-6D is a deep bedrock well instrum ented with a dedicated multi-level well system. This system (installed by USEPA as part of the Remedial Investigation [RI]) was designed and manufactured by Solinst Ltd. (Solinst) of Ontario, Canada and i ncludes inert gas driven pumps, sample tubes, pressure transducers, and cables. This system is reporte dly constructed around a 3-inch inside diameter poly vinyl chloride (PVC) pipe that serves as a condui t for the sample tubes and transducer cables. Discrete sample intervals are separated by inflatable p ackers, which contain a water-activated material inside a rubber sleeve. Groundwater samples were colle cted previously from intervals MW-6D-2 and MW-6D-4 between 1994 and 2005.

2 

### Although the MW-6D installation is not designed to be sampled in a traditional low-flow manner, for the 2011 and 2012 sampling events, methods were used that are consi stent with Sanborn Head’s previous sampling of these locations (from November 1996 to 2005), and t he QAPP (e.g., low flow rate, stabilization of parameters, field quality assurance/quality control).

### January 16, 2013 Page 2 20130116_LTG_2012_Annual_Rpt.docx 2049.04 

## Groundwater samples were collected from intervals MW-6D-2 and M W-6D-4 using the previously-installed, dedicated Solinst inert gas-driven pumps and sampling tubes. Sampling techniques for these intervals were generally similar to those used in previous sampling events conducted at the site. Water quality parameters including temperature, pH, specific co nductance, oxygen reduction potential (ORP), and dissolved oxygen (DO) were monit ored during purging using an YSI Model 556 MPS multi-parameter water quality meter with an in-line flow cell. Turbidity was monitored via a sampling port installed prior to the flow cell using a Hach 2100P turbidity meter. Upon parameter stabilization, the in-lin e flow cell was disconnected and primary and duplicate groundwater samples were collected. A summary of stabilized water quality parameter data and related field sampling informa tion for the November 2012 event is presented on the Groundwater Quality Field Sampli ng Summary form included as Attachment B. Historical water quality parameter da ta are summarized in Table 1. As indicated above, in addition to the analysis of VOCs at MW-2 R, additional groundwater samples were collected and analyzed in November 2012. These add itional analyses consisted of VOCs, 1,4-dioxane, and total (unfiltered) metals ( i.e., antimony, arsenic, barium, beryllium, and chromium) from MW-2R, MW-6D-2, and MW-6D -4. The reporting limit of 0.25 micrograms per liter (μg/l) was used for 1,4-diox ane during the 2012 sampling event based on an October 19, 2011 letter from NHDES t o investigators performing work at sit es managed by NHDES’ Waste Management Div ision. Groundwater samples were placed in the following pre-cleaned sa mple containers provided by the analytical laboratory:

 

## VOCs : 40-milliliter (ml) glass vials with Teflon® septa, pre-preser ved with hydrochloric acid (HCl);

 

## 1,4-dioxane : 40-ml glass vials with Teflon® septa, un-preserved; and

 

## Metals : 200-ml plastic bottles, pre-preserved with nitric acid (HNO 3 

## ). Following collection, sample containers were stored in a cooler packed with ice and transported to Eastern Analytical, Inc. (EAI) of Concord, New H ampshire, a New Hampshire certified laboratory, via laboratory courier for: VOC analysis by USEPA Method 8260B; 1,4- dioxane by USEPA Method 8260B in Selective Ion Monitoring (SIM) mode; and metals by USEPA Method 6020. The samples w ere handled and transported fol lowing standard chainof-custody procedures. A trip blank, prepared beforehand by EAI , was also analyzed for VOCs by USEPA Method 8260B and 1,4-dioxane by USEPA Method 8260 B SIM. A field duplicate sample (designated, “DUP-1”) was collected from MW-6D -2 and submitted to EAI for analysis using the same meth ods as the prima ry field sample s. A copy of EAI’s analytical laboratory data report for this moni toring event is included as Attachment C. Sanborn Head performed an assessment of data qual ity and usability as described in Sanborn Head’s December 2009 QAPP (refer to Attach ment D).

### January 16, 2013 Page 3 20130116_LTG_2012_Annual_Rpt.docx 2049.04


## SUMMARY OF ANALYTICAL RESULTS As indicated above, Sanborn Head performed an assessment of dat a quality and usability (Attachment D). Based on this assessment, the data are of suffi cient quality for their intended purpose (i.e., comparison to applicable groundwater st andards). Results from the November 2012 gr oundwater quality monitoring a re summarized below:

 

## MW-2R: 1,1-dichloroethane (1,1-DCA), 1 ,1-dichloroethene (1,1-DCE), an d 1,4-dioxane were the only VOCs detected in the sample from MW-2R. The conce ntration of 1,1-DCA (7 μg/l) was below its groundwater cleanup level (81 μg/l), as was the concentration of 1,1-DCE (4 μg/l) with a cleanup level (7 μg/l). The concentrati on of 1,1-DCA was equal to the concentration recorded in 2011; the 1,1-DCE concentratio n was slightly above the 2011 concentration (4 μg/L [2012] vs. 3 μg/l [2011]). The c oncentration of 1,4- dioxane (0.35 μg/l) was below its NHDES Ambient Groundwater Qua lity Standard (AGQS) [3 μg/l], and was equal to the 10 -6 

## excess lifetime cancer risk (ELCR) drinking water value 3

 

## MW-6D-2: 1,1-DCA, toluene, and 1,4-dioxane were the only VOCs detected in the sample collected from MW-6D-2, and the concentration of 1,1-DCA (4 μg/l in both the primary and duplicate samples) was well below its groundwater c leanup level (81 μg/l). The concentration of toluene (2 μg/l in both the primary and duplicate samples) was also well below its groundwater cleanup level (1,000 μg/l). The concentration of 1,4-dioxane in the primary sample (0.35 μg/l) was below its NHD ES AGQS (3 μg/l), and equal to USEPA’s 10 -6 

## ELCR drinking water value, while the 1,4-dioxane concentration in the duplicate sample (0.40 μg/l), slightly exceeded USEPA’s 10 -6 

## ELCR value. Arsenic was detected at a concentration of 1.1 μg/l in the primary samp le (1.5 μg/l in the duplicate sample), below its groundwater cleanup level of 10 μg /l. Barium was detected at 220 μg/l in the primary sample and duplicate samples, well b elow its groundwater cleanup level (2,000 μg/l). Anti mony, beryllium, and chromium w ere not detected above laboratory reporting limits in 2012. Overall, the 2012 VO C and metals concentrations at MW-6D-2 are generally consistent with 2011 re sults. . 1,4-dioxane was detected at 0.45 μg/l at MW-2R in 2011. Arsen ic was detected at 1 μg/l, below its groundwater cleanup level of 10 μ g/l. Barium was detected at 370 μg/l, below its groundwater cleanup level of 2,000 μg/l . Beryllium and chromium were each detected at 2 μg/l, below their groundwater cleanup levels, 4 μg/l and 100 μg/l, respectively. Antimony was not detected above the laboratory reporting limit in 2012. Overall, the 2012 VOC and metals concentrations at MW-2R are generally consistent with 2011 results.

 

## MW-6D-4: Similar to MW-6D-2, 1,1-DCA, to luene, and 1,4-dioxane were the only VOCs detected in the sample collected from MW-6D-4. The concentratio n of 1,1-DCA (3 μg/l) was well below its groundwater cl eanup level (81 μg/l). Toluene was detected at 1 μg/l, well below its groundwater cleanu p level (1,000 μg/l). 1,4-diox ane was detected at 0.28 μg/l, below its NHDES AGQS (3 μg/l) and USEPA’s 10 -6 

## ELCR drinking water value (0.35

3 

### USEPA. 2010. Toxicological Review of 1,4-Dioxane, In Support of Summary Information on the Integrated Risk Information System (IRIS) . EPA/635/R-09/005-F. Dated Augus t 2010.

# Sanborn, Head and Associates, Inc. Digitally signed by Sanborn, Head and Associates, Inc. DN: cn=Sanborn, Head and Associates, Inc., o=Sanborn, Head & Associates, Inc., ou=SHA, email=lsmith@sanbornhead.com, c=US Date: 2013.01.22 16:41:56 -05'00' january 16 , 2 01 3 201 3 0116_LTG _2 01 2 _Annuai_Rptdocx Page4 2049.04 

## Jlg/1). Arsenic was detected at a concentration of 0.6 llg/1, below its groundwater cleanup level (10 Jlg/1). Barium was detected at 240 Jlg/1, below its groundwater cleanup level (2,000 Jlg/1). Chromium was detected at 4 Jlg/1, below its groundwater cleanup level (100 Jlg/1). Antimony and beryllium were not detected at this location in 2012

. Overall, the 2012 VOC and metals concentrations at MW-60-4 are generally consistent with 2011 results. 

## CLOSING Results of the November 2012 groundwater monitoring at the Town Garage/Radio Beacon Site in Londonderry, New Hampshire indicate generally similar concentrations to those recorded in 2011. These concentrations are consistent with historically improving groundwater quality conditions in the vicinity of monitoring wells MW-2R, MW-60-2 and MW-60-4, with concentrations of all contaminants below their cleanup levels, and at or near to their lowest concentrations recorded since monitoring began in 1994

. The concentrations of 1,4-dioxane were well below the NHDES 

## AGQS, and below to slightly above the USEPA's 10
· 6 ELCR drinking water value of 0.35 Jlg/1.
The results of 2012 monitoring indicate the site groundwater has met the conditions of the GMP (i.e., groundwater concentrations below their respective cleanup levels for two consecutive rounds); and hence considering the recent expiration of the site GMP on Nov ember 25, 2012, we do not propose to renew the GMP. In addition, the Record of Decision (ROD) requires no exceedances of groundwater cleanup levels for a period of three consecutive years, and with the November 2012 results constituting the third consecutive annual sampling event at MW-2R with no exceedances of groundwater cleanup standards, we propose to move to site closure. As one of the first steps in this process, we recommend meeting with USEPA and NHDES at their earliest convenience to confirm the scope ofthe risk assessment. We propose to engage a risk assessor for the meeting with the Agencies

. Following concurrence from the Agencies regarding the scope of the risk assessment, working with our risk assessor we will conduct an analysis of potential risk related to site groundwater. The findings of the risk assessment would be provided to the Agencies for review.
We greatly appreciate the opportunity to continue working with you on this project. I f you have any questions or issues regarding the information

## provide~~WJ~**~e** contact us.**-- ---~,¢** **~**


# rft imot

. ite, P.G.

# ~(!:23;:;~ Charles A. Crocetti, Ph.D., P.G. Principal

SA N BO RN

# ~~**~~** H E AD

### January 16, 2013 Page 5 20130116_LTG_2012_Annual_Rpt.docx 2049.04



## SRN/CAC: tmw
Encl. Tables 1 and 2 Figures 1-4 Attachment A – Limitations Attachment B – Groundwater Quality Field Sampling Summary Form Attachment C – Analytical Laboratory Data Report Attachment D – Data Quality / Data Usability Assessment

S:\CONDATA\2000s\2049.04\Source Files\2012 Annual Report\201301 16_LTG_2012_Annual_Rpt.docx

# TABLESTABLE 1 Summary of VOCs and Chloride An alytical Data - Monitoring Wells Town Garage / Radio Beacon Site

Londonderry, New Hampshire

NHDES Site No. 198509001 Monitoring Well Location Chloride (mg/l) 1,1-DCA ( μg/l) 1,1-DCE ( μg/l) 1,1,1-TCA ( μg/l) Other VOCs ( μg/l) Cleanup Levels 250 mg/l 81 μg/l 7 μ g/l 200 μ g/l 6/3/1994 10,900 100 37 300 12/6/1994 12,410 100 48 360 4/20/1995 11,530 120 58 280 10/12/1995 9,000 120 62 320

5/1/1996 11,300 150 86 360 6.9 - Chloroethane 11/27/1996 NS 110 50 240 11/20/1997 NS 100 64 160 1 - Toluene 11/21/97 Dup. NS 110 70 180

11/10/1998 NS 110 58 150 1 - Toluene 7 - Chloroethane 11/23/1999 NS 86 40 85 8 - Chloroethane 11/21/2000 NS 120 48 56 13 - Chloroethane 11/19/2001 NS 100 48 52 17 - Chloroethane 11/15/2002 NS 57 28 28 7 - Chloroethane 11/15/02 Dup. NS 59 30 28 8- Chloroethane

11/4/2003 NS 57 28 19 10 - Chloroethane 11/4/03 Dup. NS 56 27 19 8 - Chloroethane

11/4/2004 NS 46 18 11 7 - Chloroethane 11/4/04 Dup. NS 46 19 11 8 - Chloroethane 11/29/2005 NS 36 18 8 5 - Chloroethane 11/29/05 Dup. NS 37 18 8 6 - Chloroethane

11/13/2006 NS 33 18 7 5 - Chloroethane 12/11/2006 NS 36 21 8 6 - Chloroethane 11/9/2007 NS 21 14 3 11/6/2008 NS 17 9 BDL 5/19/2010 NS 11 7 BDL 05/19/10 Dup. NS 11 7 BDL

11/22/2011 NS 7 3 BDL 0.44 - 1,4-Dioxane 11/19/2012 NS 7 4 BDL 0.35 - 1,4-Dioxane Date MW-2D/2R Location (GMP sampling location)

MW-2R Installed 10/30/06 MW-2D-6

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Londonderry, New Hampshire

NHDES Site No. 198509001 Monitoring Well Location Chloride (mg/l) 1,1-DCA ( μg/l) 1,1-DCE ( μg/l) 1,1,1-TCA ( μg/l) Other VOCs ( μg/l) Cleanup Levels 250 mg/l 81 μg/l 7 μ g/l 200 μ g/l Date

MW-6D* 11/1/1990 NS 13 6 BDL
6/2/1994 NS 6.6 2.5 BDL 3.80 - THM 7.50 - Toluene

340 - MEK 150 - Acetone 5/9/1996 8,480 16 2.2 BDL 7.8 - Carbon disulfide 40 - MEK 25 - Toluene 6/2/1994 8,800 11 7 BDL 1.50 - Toluene 12/1/1994 9,050 13 7.1 BDL 4/20/1995 8,714 10 6.3 BDL 1.10 - MTBE 1.80 - Toluene 10/10/1995 9,300 12 6.1 BDL 2.3 - MTBE

5/9/1996 7,350 11 6.8 BDL 2.6 - Toluene 11/26/1996 NS 10 5 BDL 11/20/1997 NS 12 8 BDL 1 - Toluene 11/9/1998 NS 10 6 BDL 2 - Toluene 11/22/1999 NS 9 4 BDL 1 - Toluene 11/17/2000 NS 11 4 BDL 11/17/00 Dup. NS 10 3 BDL

11/19/2001 NS 11 5 BDL 1 - Toluene 11/14/2002 NS 13 5 BDL 1 - Toluene 11/5/2003 NS 9 3 BDL 2 - Toluene 11/3/2004 NS 8 2 BDL 1 - Toluene 11/28/2005 NS 6 1 BDL 1 - Toluene 11/22/2011 NS 3 BDL BDL 2 - Toluene 0.34 - 1,4-Dioxane 11/22/11 Dup. NS 3 BDL BDL 2 - Toluene 0.35 - 1,4-Dioxane 11/19/2012 NS 4 BDL BDL 2 - Toluene 0.35 - 1,4-Dioxane 11/19/12 Dup. NS 4 BDL BDL 2 - Toluene 0.40 - 1,4-Dioxane MW-6D-2 MW-6D Location (monitoring well not sampled as part of GMP)

MW-6D-1

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Londonderry, New Hampshire

NHDES Site No. 198509001 Monitoring Well Location Chloride (mg/l) 1,1-DCA ( μg/l) 1,1-DCE ( μg/l) 1,1,1-TCA ( μg/l) Other VOCs ( μg/l) Cleanup Levels 250 mg/l 81 μg/l 7 μ g/l 200 μ g/l Date

6/2/1994 2,200 3.2 1.5 BDL 12/1/1994 1,860 3.6 1.7 BDL 1.50 - Toluene 4/20/1995 2,379 3 1.4 BDL 1.50 - Toluene 10/10/1995 7,850 14 6.3 BDL 2.40 - MTBE

5/9/1996 1,570 2.6 BDL BDL 6/2/1994 3,800 5.2 BDL BDL 2.60 - 1,2 DCA 12/1/1994 4,590 8.5 3.4 BDL 4/20/1995 3,621 5 2.1 BDL 10/10/1995 7,410 18 6.6 4.5 1.40 - MTBE

5/9/1996 2,210 3.5 2.1 BDL 11/26/1996 NS 6 3 BDL 1 - Toluene 11/20/1997 NS 18 9 BDL 11/9/1998 NS 16 7 BDL 1 - Toluene 11/22/1999 NS 9 4 BDL 11/17/2000 NS 12 4 BDL 11/19/2001 NS 17 6 BDL 11/14/2002 NS 16 5 BDL 1 - Toluene 11/5/2003 NS 7 2 BDL 11/3/2004 NS 6 2 BDL 11/28/2005 NS 2 BDL BDL 1 - Toluene 11/22/2011 NS BDL BDL BDL 2 - Toluene 11/19/2012 NS 3 BDL BDL 1 - Toluene 0.28 - 1,4-Dioxane

Nov-90 440 BDL BDL BDL 5/9/1994 257 BDL BDL BDL 2.20 - THM 11/3/1994 NS BDL BDL BDL 4.20 - THM 4/26/1995 192 BDL BDL BDL 2.5 - THM 11/1/1990 NS BDL BDL BDL 5/9/1994 833 BDL BDL BDL 12/6/1994 797 BDL BDL BDL 4/26/1995 810 BDL BDL BDL

Nov-90 3,410 74 18 790 5/11/1994 1,682 59 15 200 11/3/1994 1,170 150 29 450 4/21/1995 1,211 78 25 200 10/12/1995 2,440 150 31 410 14 - MTBE

5/2/1996 760 30 6.7 79 11/26/1996 NS 23 4 59 11/20/1997 NS 33 8 81 Replacement Well installed 11/18/99 11/22/1999 NS BDL BDL 4 12/6/2000 NS 4 1 9 11/19/2001 NS 6 2 12 8 - THM 11/19/01 Dup. NS 6 2 12 7 - THM

11/15/2002 NS BDL BDL BDL 11/4/2003 NS BDL BDL BDL 5 - THM 11/3/2004 NS BDL BDL BDL 11/28/2005 NS BDL BDL BDL MW-2D* Nov-90 3,960 46 41 BDL MW-1S

MW-1D

MW-2S Decommissioned Wells MW-6D Location (cont'd)

MW-6D-3

MW-2S MW-6D-4

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Londonderry, New Hampshire

NHDES Site No. 198509001 Monitoring Well Location Chloride (mg/l) 1,1-DCA ( μg/l) 1,1-DCE ( μg/l) 1,1,1-TCA ( μg/l) Other VOCs ( μg/l) Cleanup Levels 250 mg/l 81 μg/l 7 μ g/l 200 μ g/l Date

4/20/1995 5,749 100 9.1 7.3 180 - MTBE 24 - Toluene
10/13/1995 4,090 31 5.2 6.3 110 - MEK 4.8 - THM 6.1 - Toluene 2.2 - Carbon disulfide

5/1/1996 4,100 69 12 5.3 3.5 - Carbon disulfide 3.3 - THM 130 - MEK 10 - Toluene 5.6 - Chloroethane 12/6/1994 5,420 46 4.5 6.9 12 - Toluene 390 - MEK 4/20/1995 5,484 140 13 BDL 72 - Toluene 10/13/1995 4,270 160 17 BDL 75 - Toluene 6.7 - Dimethyl sulfide 5/1/1996 2,800 87 19 BDL 64 - Acetone 8.4 - Carbon disulfide 120 - Toluene 11/27/1996 NS 20 BDL BDL 180 - Toluene 600 - MEK 11/20/1997 NS 12 9 BDL 82 - Toluene 220 - MEK 10 - 2-Hexanone 11/10/1998 NS 9 8 BDL 67 - Toluene 60 - MEK 11/23/1999 NS 5 4 BDL 14 - Toluene 10 - MEK 11/21/2000 NS 6 4 BDL 10 - Acetone 30 - MEK 11 - Toluene 11/19/2001 NS 6 4 BDL 20 - Acetone 20 - MEK 14 - Toluene 11/15/2002 NS 4 3 BDL 20 - Acetone 10 - MEK 13 - Toluene 11/4/2003 NS 4 3 BDL 10 - Acetone 9 - Toluene 11/4/2004 NS 6 3 BDL 20 - Acetone 11 - Toluene 11/28/2005 NS 6 3 BDL 20 - Acetone 13 - Toluene 12/6/1994 2,339 7 6.2 2.6 1.20 - Toluene 4/20/1995 2,458 6.5 5.1 1.7 1.20 - Toluene 10/13/1995 2,410 6.6 5.5 1.7 1.5 - MTBE

5/1/1996 2,400 7.8 9.2 BDL 3.3 - MTBE 6/3/1994 NS BDL BDL 7.6 12/6/1994 7,390 11 8 6.4 4/20/1995 7,979 12 8 5.5 10/12/1995 8,810 14 9.9 5.7 2 - MTBE

5/1/1996 8,700 22 20 9.9 2.8 - MTBE MW-2D-2 MW-2D-1

MW-2D-3

MW-2D-4 Decommissioned Wells (cont'd)

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Londonderry, New Hampshire

NHDES Site No. 198509001 Monitoring Well Location Chloride (mg/l) 1,1-DCA ( μg/l) 1,1-DCE ( μg/l) 1,1,1-TCA ( μg/l) Other VOCs ( μg/l) Cleanup Levels 250 mg/l 81 μg/l 7 μ g/l 200 μ g/l Date

6/3/1994 36,000 33 17 34 12/6/1994 18,980 19 15 23 4/20/1995 17,940 34 20 27 10/12/1995 17,400 37 25 20 2.4 - MTBE

5/1/1996 18,800 50 44 30 2.1 - Chloroethane

Nov-90 42 BDL BDL BDL 5/17/1994 39 BDL BDL BDL 11/3/1994 74 6.8 BDL BDL 4/17/1995 29 BDL BDL BDL 10/11/1995 137 BDL BDL BDL 1.1 - Chloroethane 1.7 - THM 2.5 - MTBE 5/13/1996 20 BDL BDL BDL

Nov-90 580 15 BDL BDL 5/17/1994 4,537 11 5.8 BDL 12/1/1994 4,260 11 6.2 BDL 4/17/1995 4,425 9.4 5.1 BDL 10/11/1995 212 11 5.2 BDL 5/13/1996 4,400 12 8.3 BDL 11/26/1996 NS 8 4 BDL 11/20/1997 NS 8 6 BDL 11/9/1998 NS 7 4 BDL 11/22/1999 NS 5 3 BDL 11/22/99 Dup. NS 5 3 BDL

11/17/2000 NS 6 2 BDL 11/19/2001 NS 6 2 BDL 11/14/2002 NS 4 2 BDL 11/5/2003 NS 4 1 BDL 11/3/2004 NS 3 1 BDL 11/28/2005 NS 3 1 BDL

Nov-90 2,880 BDL BDL BDL 5/11/1994 1,124 4.2 BDL BDL 1.40 - Chloroethane 11/3/1994 3,124 6.6 BDL BDL 4/25/1995 2,010 3.6 BDL BDL 4.10 - MTBE 2.20 - Chloroethane 10/17/1995 3,300 4.6 BDL BDL 1.2 - MTBE 4/24/1996 1,210 2.8 BDL BDL 2.7 - Chloroethane MW-4D* Nov-90 23,500 19 18 25

MW-4D-1 4/26/1996 3,810 7.7 5.9 3.8 2 - Carbon disulfide 6.2 - THM 43 - MEK 2.1 - Methylene chloride 2.9 - Toluene MW-3D MW-3S MW-2D-5 Decommissioned Wells (cont'd)

MW-4S

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Londonderry, New Hampshire

NHDES Site No. 198509001 Monitoring Well Location Chloride (mg/l) 1,1-DCA ( μg/l) 1,1-DCE ( μg/l) 1,1,1-TCA ( μg/l) Other VOCs ( μg/l) Cleanup Levels 250 mg/l 81 μg/l 7 μ g/l 200 μ g/l Date

4/26/1995 24,850 5.1 7.5 4.2 3.50 - THM 9.80 - Toluene
4/26/1996 22,300 8 11 4.5 2.5 - Carbon disulfide 3.2 - THM 3 - Methylene Chloride 4.5 - Toluene 11/25/1996 NS 7 7 3 3 - THM 4 - Toluene 11/20/1997 NS 10 10 2 2 - THM 3 - Toluene 11/10/1998 NS 9 5 BDL 2 - Toluene 11/23/1999 NS 9 5 BDL 4 - Toluene 20 - MEK 11/21/2000 NS 13 6 BDL 20 - Acetone 50 - MEK 4 - Toluene
11/20/2001 NS 13 8 3 20 - Acetone 2 -THM 40 - MEK 4 - Toluene 11/15/2002 NS 6 2 BDL 20 - MEK 3 - Toluene
11/4/2003 NS 9 6 3 20 - Acetone 2 -THM 30 - MEK 4 - Toluene 11/4/2004 NS 9 5 BDL 20 - MEK 4 - Toluene 11/29/2005 NS 9 6 2 10 - Acetone 20 - MEK 4 - Toluene 6/2/1994 22,000 7.6 6.5 41 3.50 - MTBE 12/6/1994 19,720 9.2 6.9 43 2.90 - MTBE 4/26/1995 12,000 9.5 7.5 31 10/17/1995 12,900 8.9 3.6 21 2.2 - MTBE 4/26/1996 13,700 11 5.6 24 2.4 - MTBE 2.7 - Chloroethane 11/25/1996 NS 9 2 15 11/20/1997 NS 10 2 10 11/10/1998 NS 7 1 6 11/23/1999 NS 4 BDL 3 11/21/2000 NS 3 BDL BDL 11/20/2001 NS 3 BDL BDL 11/15/2002 NS BDL BDL BDL 11/4/2003 NS BDL BDL BDL 11/4/2004 NS BDL BDL BDL 11/29/2005 NS BDL BDL BDL MW-4D-3 MW-4D-2 Decommissioned Wells (cont'd)

\\conserv1\DataShare\DATA\CONDATA\2000s\2049.04\Source Files\LT G Tables.xlsx Page 6 of 9 Sanborn, Head & Associates, Inc.TABLE 1 Summary of VOCs and Chloride An alytical Data - Monitoring Wells Town Garage / Radio Beacon Site

Londonderry, New Hampshire

NHDES Site No. 198509001 Monitoring Well Location Chloride (mg/l) 1,1-DCA ( μg/l) 1,1-DCE ( μg/l) 1,1,1-TCA ( μg/l) Other VOCs ( μg/l) Cleanup Levels 250 mg/l 81 μg/l 7 μ g/l 200 μ g/l Date

Nov-90 3,550 14 21 190 5/18/1994 3,640 2.2 13 89 11/3/1994 2,040 BDL 14 100 4/25/1995 4,072 BDL 9.4 43 10/17/1995 3,000 2.1 13 64 1.4 - PCE 4/24/1996 5,120 2.2 15 81 11/25/1996 NS BDL 9 55 11/20/1997 NS BDL 12 52 11/10/1998 NS BDL 5 27 11/23/1999 NS BDL 4 21 12/6/2000 NS BDL 5 19 7 - MTBE 11/20/2001 NS BDL 3 11 10 - MTBE 11/15/2002 NS BDL 4 11 5 - MTBE 11/4/2003 NS BDL 3 9 11/4/2004 NS BDL 2 5 11/29/2005 NS BDL 1 4 MW-5D* Nov-90 1,110 9 10 66 MW-5D-1 4/25/1996 NS 5 2.4 4.8 96 - Acetone 2.4 - Carbon disulfide 20 - Toluene MW-5D-2 4/25/1996 1,290 BDL BDL 7.1 5.2 - Carbon disulfide 5.1 - THM 4.1 - Toluene 6/3/1994 1,900 3.1 5.4 15 4/25/1996 1,790 BDL 2.6 6.3 6/3/1994 6,900 NS NS NS 12/6/1994 6,110 BDL BDL 4.5 4/25/1995 5,780 BDL BDL BDL 10/11/1995 5,760 1 TRACE 2.2 1.6 - MTBE 4/25/1996 6,030 BDL BDL 3.7 3.5 - MTBE 11/25/1996 NS BDL BDL 2 11/20/1997 NS BDL BDL BDL 11/10/1998 NS BDL BDL BDL 11/23/1999 NS BDL BDL BDL 11/21/2000 NS BDL BDL BDL 10 - MTBE

Nov-90 100 BDL BDL BDL 5/17/1994 191 BDL BDL BDL 5/25/1994 174 NS NS NS 11/3/1994 301 BDL BDL BDL 4/17/1995 118 BDL BDL BDL

Nov-90 46 BDL BDL BDL 5/17/1994 95 BDL BDL BDL 11/3/1994 107 BDL BDL BDL 4/17/1995 70 BDL BDL BDL 11/1/1990 35 BDL BDL BDL 5/17/1994 105 BDL BDL BDL 12/6/1994 103 BDL BDL BDL 4/17/1995 99 BDL BDL BDL MW-7D MW-5D-3

MW-5S

MW-7S MW-6S MW-5D-4 Decommissioned Wells (cont'd)

\\conserv1\DataShare\DATA\CONDATA\2000s\2049.04\Source Files\LT G Tables.xlsx Page 7 of 9 Sanborn, Head & Associates, Inc.TABLE 1 Summary of VOCs and Chloride An alytical Data - Monitoring Wells Town Garage / Radio Beacon Site

Londonderry, New Hampshire

NHDES Site No. 198509001 Monitoring Well Location Chloride (mg/l) 1,1-DCA ( μg/l) 1,1-DCE ( μg/l) 1,1,1-TCA ( μg/l) Other VOCs ( μg/l) Cleanup Levels 250 mg/l 81 μg/l 7 μ g/l 200 μ g/l Date

Nov-90 3,460 BDL BDL BDL 5/10/1994 597 BDL BDL BDL 11/3/1994 2,105 2.1 BDL 4.6 4/18/1995 895 BDL BDL BDL 10/16/1995 2,700 BDL BDL 5.8

5/3/1996 865 BDL BDL BDL

Nov-90 9,130 48 28 BDL 5/10/1994 1,004 BDL BDL 2 11/3/1994 2,439 2.7 1.3 2.7 4/18/1995 1,122 BDL BDL 1.2 10/16/1995 8,700 11 6 2.9 1.8 - MTBE

5/3/1996 2,140 2.5 BDL 3 11/27/1996 NS 7 4 BDL 11/20/1997 NS 7 5 BDL 11/9/1998 NS 5 3 BDL 11/9/98 Dup. NS 5 3 BDL 11/22/1999 NS 3 2 BDL

11/17/2000 NS 3 1 BDL 16 - Chloromethane 21 - Vinyl Chloride 20 - Acetone 15 - Carbon Disulfide 46 - Benzene 9 - Toluene 4 - Styrene 11/19/2001 NS 4 1 BDL 11/14/2002 NS 2 1 BDL 11/4/2003 NS 3 1 BDL 11/3/2004 NS 2 BDL BDL 11/28/2005 NS BDL BDL BDL

Nov-90 530 BDL BDL BDL 5/11/1994 499 BDL BDL 1.6 11/3/1994 869 BDL BDL 12 4/18/1995 642 BDL BDL 1.2 10/13/1995 860 BDL BDL 11

5/2/1996 490 BDL BDL BDL 6/2/1996 191 BDL BDL BDL 12/8/1994 347 BDL BDL BDL 1.4 - Toluene 4/26/1995 228 BDL BDL BDL 10/17/1995 200 BDL BDL BDL

5/7/1996 130 BDL BDL BDL 5/18/1994 148 1.5 BDL BDL 1.1 - Chloromethane 12/9/1994 118 2.3 BDL BDL 4/26/1995 162 1.4 BDL BDL 10/17/1995 200 1.8 BDL BDL

5/7/1996 156 BDL BDL BDL RWGD MW-8S

MW-9S

RWGS MW-8D Decommissioned Wells (cont'd)

\\conserv1\DataShare\DATA\CONDATA\2000s\2049.04\Source Files\LT G Tables.xlsx Page 8 of 9 Sanborn, Head & Associates, Inc.

### TABLE 1 Summary of VOCs and Chloride Analytical Data - Monitoring Wells Town Garage / Radio Beacon Site

Londonderry, New Hampshire

NHDES Site No. 198509001 Notes: 1. "1,1-DCA" indicates 1,1-dichloroethane. 

### "1 ,1-DCE" indicates 1,1-dichloroethene. "1 ,1,1-TCA" indicates 1,1,1-trichloroethane. "MEK" indicates methyl-ethyl-ketone. "MTBE" indicates methyl-t-butyl ether. "THM" indicates chloroform. "BDL" indicates below laboratory reporting limit. "NS" indicates not sampled.
2. Underline indicates that the well was sampled in 2012 (MW-2R, MW-6D -2, and MW- 6D-4 only.). 3. Shading indicates exceedance of Site Cleanup Level.
4. "*" indicates that monitoring wells MW-2D, MW-4D, MW-5D, and MW-6 D were converted to permanent Solinst multilevel wells in 1992. 5. Cleanup levels: chloride = 250 mg/l; 1,1-DCA = 81 μg/l; 1,1-DCE = 7 μg /l ; 1,1,1- TCA = 200 μg/l. Note that exceedances are shaded. 6. Although not shaded in the above table, the November 2000 sample from MW-8D contained two analytes that exceeded MCLs: benzene and vinyl ch loride, with MCLs of 5 μg/l and 2 μg/l respectively.

S:\CONDATA\2000s\2049.04\Source Files\2012 Annual Report\LTG Ta bles.xlsx Page ͻ of ͻ Sanborn, Head & Associates, Inc.TABLE 2Summary of Analytical Results – Supplemental Groundwater AnalysesTown Garage/Radio Beacon SiteLondonderry, New HampshireNHDES Site No. 198509001Concentrations inμg/l.MW-2R MW-6D-2 MW-6D-405/19/1005/19/10Dup.11/22/11 11/19/12 11/22/1111/22/11Dup.11/19/1211/19/12Dup.11/22/11 11/19/12Dioxane (1,4-) 3†<1 <1 0.44 0.35 0.34 0.35 0.35 0.40 <0.25 0.28Antimony 6 NA <5 <2 <5 <5 <2 <2 <5 <2Arsenic 10 NA <1 <1 <5 1.0 <5 <5 1.1 1.5 <5 0.6Barium 2,000 NA 400 370 210 200 220 220 85 240Beryllium 4 NA <1 2 <1 <1 <2 <2 <1 <2Chromium 100 NA <5 2 <5 <5 <2 <2 <5 4AnalyteGW-1(AGQS)GW-2Notes:1. Samples were collected by Sanborn Head on the dates indicated and analyzed by Eastern Analytical, Inc. of Concord, New Hampshire for 1,4-dioxane United StatesEnvironmentalProtection Agency (USEPA) Method 8260B in selective ion monitoring (SIM) mode, and unfiltered metals by USEPA Method 6020.2. Concentrationsare presented in micrograms per liter (μg/l) which are equivalent to parts per billion (ppb).3. Ablank indicates the sample wasnot analyzed for this analyte."<"indicates the analyte was not detected above the indicated laboratory reporting limit.4. "GW-1" and "GW-2" Groundwater Standards are from the New HampshireDepartment of Environmental Services (NHDES) Contaminated Sites RiskCharacterization andManagementPolicy (RCMP) (January 1998, with 2000 through 2007 revisions/addenda). GW-1 Groundwater Standards are equivalent to the Ambient GroundwaterQualityStandards(AGQSs) promulgated in Env-Or 600 (July 2008). The AGQS/GW-1Groundwater Standards are intended to be protective of groundwater as a source ofdrinkingwater. The GW-2 Groundwater Standards apply to groundwater as a potential source of indoor air contamination5."†"indicates the RCMP lists as not currently available."NA"indicates the RCMP lists as not applicable.S:\CONDATA\2000s\2049.04\Source Files\2012 Annual Report\LTG Tables.xlsxPage 1 of 1 Sanborn, Head & Associates, Inc.

# FIGURESTAX MAP 9 TAX MAP 6TOWN GARAGEPROPERTYMW-2RMW-6D-2,4File:S:\CONDATA\2000s\2049.04\Graphics Files\CAD\2012 Summary Report\GW_Monitoring_Locations.dwg Plot Date: 1-7-13c 2013 SANBORN, HEAD & ASSOCIATES, INC.This figure depicts the approximate locations ofthe remaining site monitoring wells MW-2R andMW-6D.Figure Narrative1. This base map was prepared based on a copyof the 400 scale 2007 Town of Londonderry TaxAssessor's Map printed from the Town ofLondonderry websitewww.londonderrynh.org onAugust 8, 2007 and should be consideredapproximate. Refer to the legal property anddeeded easement descriptions for more accurateidentification of Groundwater Management Zone(GMZ) boundaries.2. The location of monitoring well MW-6D isbased on a plan entitled, "Plate 3, Location ofMonitoring Wells, Residential Wells, GeophysicalSurvey Lines and Cross-Sections", from the FinalTechnical Report of Field Investigation, HoltonCircle Remedial Investigation, Londonderry, NewHampshire, prepared by Metcalf & Eddy, Inc.,dated March 1992.3. Monitoring well MW-2R was installed byGeosearch, Inc. of Fitchburg, Massachusetts onOctober 30, 2006 as a replacement to MW-2D-6.MW-2R is included in the current groundwatermonitoring program.4. Monitoring well location MW-6D is a deepbedrock well at the site instrumented with adedicated multi-level well system. This system(installed as part of the Remedial Investigation[RI]) was designed and manufactured by SolinstLtd. (Solinst) of Ontario, Canada and includesinert gas-driven pumps, sample tubes, pressuretransducers and cables. This system is reportedlyconstructed around a 3-inch inside diameter PVCpipe that serves as a conduit for the sampletubes and transducer cables. Discrete sampleintervals are separated by inflatable packers,which contain a water-activated material inside arubber sleeve. Sanborn Head had previouslycollected groundwater samples from intervalsMW-6D-2 and MW-6D-4. MW-6D is not includedin the current groundwater monitoring program;however, similar to 2011, sampling intervalsMW-6D-2 and MW-6D-4 were included in theNovember 2012 sampling event.NotesLegendGRAPHICAL SCALE60'120'0120'240'MW-2RMW-6D-2,4Approximate Groundwater Management Zone (GMZ) BoundaryApproximate Property BoundaryApproximate Tax Map BoundaryTax Map Lot NumberReplacement shallow bedrock monitoring well location and designation included inthe groundwater monitoring program as described in the June 2006 RevisedAmendment No. 2 to the SOW.As described in the June 2006 Revised Amendment No. 2 to the SOW, themonitoring well was removed from the groundwater monitoring program and notdecommissioned. Similar to 2011, this monitoring well was included in theNovember 2012 sampling event.SAN NBOR HEADMonitoring Well LocationPlan2012 Annual Summary ReportGroundwater Monitoring ProgramLondonderry Town Garage/RadioBeacon SiteLondonderry, New HampshireFigure 1T. WhiteD. Dombrowsky/E. Wright2049.04S. NerneyJanuary 2013Project No:Reviewed By:Designed By:Drawn By:Date:Note: ND = 0.1μg/l.S:\CONDATA\2000s\2049.04\Source Files\2012 Annual Report\MonWellPlot.xlsSanborn, Head & Associates, Inc.0.11101001000Jan-94 Jan-95 Jan-96 Jan-97 Jan-98 Jan-99 Jan-00 Jan-01 Jan-02 Jan-03 Jan-04 Jan-05 Jan-06 Jan-07 Jan-08 Jan-09 Jan-10 Jan-11 Jan-12 Jan-13

Concentration ( μ g/l)Sample DatesFigure 2Concentration vs. Time PlotMW-2D-6/MW-2RTown Garage/Radio Beacon SiteLondonderry, New Hampshire1,1,1-TCA1,1-DCA1,1-DCE1,1,1-TCA Cleanup Goal (200)1,1-DCA Cleanup Goal (81)1,1-DCE Cleanup Goal (7)MW-2R Installed1,4-Dioxane1,4-Dioxane AGQS (3)1,4-Dioxane 10-6 Risk (0.35)Monitoring well MW-2D-6 was replaced by monitoring well MW-2R onOctober 30, 2006 (indicated with a black vertical line on this graph). Datapoints shown from January 1994 through December 2005 reflect samplescollected from monitoring well MW-2D-6. Subsequent data starting inNovember 2006 reflect samples collected from monitoring well MW-2R.Duplicate samples were collected at this interval in 1997, and 2002 through2005. For graphing purposes, the higher of the two concentrations for eachsampling event is shown.1,4-dioxane analysis began in 2010 at this location. 1,4-dioxane was notdetected above the laboratory reporting limit (1μg/L) at this location in 2010.Data points plotting at 0.1 ug/L represent concentrations below laboratoryreporting limits.Note: ND = 0.1μg/l.S:\CONDATA\2000s\2049.04\Source Files\2012 Annual Report\MonWellPlot.xlsSanborn, Head & Associates, Inc.0.11101001000Jan-94 Jan-95 Jan-96 Jan-97 Jan-98 Jan-99 Jan-00 Jan-01 Jan-02 Jan-03 Jan-04 Jan-05 Jan-06 Jan-07 Jan-08 Jan-09 Jan-10 Jan-11 Jan-12 Jan-13

Concentration ( μ g/l)Sample DatesFigure 3Concentration vs. Time PlotMW-6D-2Town Garage/Radio Beacon SiteLondonderry, New Hampshire1,1,1-TCA1,1-DCA1,1-DCE1,1,1-TCA Cleanup Goal (200)1,1-DCA Cleanup Goal (81)1,1-DCE Cleanup Goal (7)1,4-Dioxane1,4-Dioxane AGQS (3)1,4-Dioxane 10-6 Risk (0.35)Duplicate samples were collected at this interval in 2000, 2011, and2012. For graphing purposes, the higher of the two concentrations foreach sampling event is shown.1,4-dioxane analysis began in 2011 at this interval.Data points plotting at 0.1 ug/L represent concentrations belowlaboratory reporting limitsGroundwater samples were not collectedat this interval between 2005 and 2011.Note: ND = 0.1μg/l.S:\CONDATA\2000s\2049.04\Source Files\2012 Annual Report\MonWellPlot.xlsSanborn, Head & Associates, Inc.0.11101001000Jan-94 Jan-95 Jan-96 Jan-97 Jan-98 Jan-99 Jan-00 Jan-01 Jan-02 Jan-03 Jan-04 Jan-05 Jan-06 Jan-07 Jan-08 Jan-09 Jan-10 Jan-11 Jan-12 Jan-13

Concentration ( μ g/l)Sample DatesFigure 4Concentration vs. Time PlotMW-6D-4Town Garage/Radio Beacon SiteLondonderry, New Hampshire1,1,1-TCA1,1-DCA1,1-DCE1,1,1-TCA Cleanup Goal (200)1,1-DCA Cleanup Goal (81)1,1-DCE Cleanup Goal (7)1,4-Dioxane1,4-Dioxane AGQS (3)1,4-Dioxane 10-6 Risk (0.35)1,4-dioxane analysis began in 2011 at this interval. 1,4-dioxanewas not detected above the laboratory reporting limit (0.25μg/L)at this interval in 2011.Data points plotting at 0.1 ug/L represent concentrations belowlaboratory reporting limitsGroundwater samples were not collectedat this interval between 2005 and 2011.

# ATTACHMENT A
LIMITATIONS

# A TTACHMENT 

# A L IMITATIONS
1. The conclusions and recommendations described in this letter report are based in part on the data obtained from a limited number of groundwater samples from widely spaced explorations. The nature and extent of variations betwe en these explorations may not become evident until further investigation, or remediat ion, is initiated. If variations or other latent conditions then appear evident, it w ill be necessary to reevaluate the conclusions and rec ommendations of this letter rep ort. 2. Should additional chemical dat a, historical information, or h ydrogeologic information become available in the future, such information should be revi ewed by Sanborn Head and the interpretations, conclusions and recommendations presen ted herein should be modified accordingly. 3. In preparing this letter report, Sanborn Head has relied on c ertain information provided by other parties referenced herein, and on information contained in the files of state and local agencies available at the time of the study. Although there may have been some degree of overlap in the information provided by thes e various sources, we did not attempt to independently verify the accuracy or comp leteness of all information reviewed or received during the course of this stud y. 4. Water level measurements have been made in the monitoring wel l sampling locations at times and under conditions stated within the text of the let ter report. Note that fluctuations in the level of the groundwater may occur due to v ariations in rainfall and other factors not evident at the time measurements were made. 5. Quantitative laboratory analyses were performed as part of th e investigation as noted within the letter report. The analyses were performed for spec ific parameters that were selected during the course of this study. It must be note d that additional compounds not searched for during the current study may be pres ent in indoor air, soil, groundwater, surface water, and/or sediment at the site. Moreover, it should be noted that variations in the types and concentrations of contam inants and variations in their distributions within groundwater may occur due to the passage of time, seasonal water table fluctuation s, recharge events, and other f actors. 6. The conclusions and recommendations contained in this letter report are based in part on various types of chemical data as well as historical an d hydrogeologic information developed by previous investigators. While Sanborn Head has reviewed that data and information as stated in this letter report, any of Sanborn Head’s interpretations, conclusions, and recommendations that have rel ied on that information will be contingent on its validity. 7. The analyses and recommendations contained in this letter rep ort are based on the data obtained from the referenced subsurface explorations/sampl ing locations. The explorations/sampling locations indicate conditions only at the specific locations and times, and only to the depths penetrated. They do not necessar ily reflect variations

### January 2013 Page 2 Limitations.docx 2049.03 

## that may exist between such locations. The validity of the reco mmendations is based in part on assumptions Sanborn Head has made about conditions a t the site. Such assumptions may be confirmed only during additional characteriz ation, or remediation. If subsurface conditions different from those desc ribed become evident, the recommendations in this lette r report must be re-evaluated. 8. This letter report has been prepared for the exclusive use of the Town of Londonderry, New Hampshire for specific application for environ mental conditions related to the Town Garage/Radio Beacon Site located in Londond erry, New Hampshire in accordance with generally-accepted hydrogeologic a nd environmental practices. No warranty, exp ress or implied, is made.

S:\CONDATA\2000s\2049.04\Source Files\2012 Annual Report\Att A - Limits\Limitations.docx

# ATTACHMENT B GROUNDWATER QUALITY FIELD SAMPLING SUMMARY FORM

## Groundwater Quality Field Sampling Summary
Date:

Field Measurements Sampling Location MW-2R MW-6D-2 MW-6D-4 Reference Point TPVC TOC TOC Reference Point Elevation (feet) 355.69

– – Depth to Water (feet) 4.25

– – Water Table Elevation (feet) 351.44

– Depth to Bottom (feet bgs) 48.5 99 (from TOC) 31 (from TOC) pH (standard units) 6.8 7.4 7.2 Specific Conductance (μS/cm) 12,808 8,429 7,097 Temperature (°C) 9.1 9.8 10.0 Dissolved Oxygen (mg/L) 1.2 0.1 0.3 Oxidation Reduction Potential (mV) 145 -77 -69 Turbidity (NTU) 3.18 0.76 3.8 Date of Sample 19-Nov 19-Nov 19-Nov Sample Time 0924 1053 1148 Gallons Purged 1⁄2+ 3⁄4 1⁄2
Purge/Sample Device Bladder Pump UHP Nitrogen Gas UHP Nitrogen Gas Comment Reference Number 1,2,7 1,3,4,5,7 1,6,7 Comments Weather: Clear, 20s-40s °F Project Manager: T. White Collector(s): M. Stein pH, Conductivity, Temperature, DO, ORP Meter: YSI 556 MPS Turbidity Meter: Hach 2100P Water Level Meter: QED MP30 (MW-2R); Geokon GK404 (MW-6D-2 and MW-6D-4) Project Number: 2049.04 Project Name: Londonderry Town Garage Project Location: Londo nderry, New Hampshire November 19, 2012

1. Field screening parameters were generally monitored approxi mately every five minutes during purging. After the field parameters stabilized, groundwat er samples were collected. Indi cated field parameters were the last stabilized values recorded prior to sample collection. 2. Groundwater level measurement was obtained using a QED MP30 electronic water lev el meter. The well was purged and sampled using a 3⁄4

- inch diameter bladder pump at fl ow rates of approximately 40 mL /min. The intake of the bladder pump was set at approximately 37.3 ft below ground surface [bgs], which corresponded to the approximate mid -screen depth. 3. Groundwater level measuremen t was obtained using previously

- installed Geokon, Inc. vibrati ng wire pressure transducer and a Geokon, Inc. GK -401 readout box. The well was purged and sampled using previo usly-installed, dedicated Solinst inert gas (UHP nitrogen) -driven pumps and sampling tubes at flow rates of approximately 120 mL/min. 4. Field duplicate (labeled "Dup -1") collected. 5. The groundwater elevation calculated from measurements made using the Geokon are approxim ately 30 feet lower than historical values for MW -6D-2, suggesting that the pressu re transducer permanently inst alled in the well may be malfunctioning. 

### 6. The pressure transducer installed in MW-6D-4 was not operational at the time of measurement. T he well was purged and sampled using previously-installed, dedicated Solinst inert gas (UHP nitrogen )- driven pumps and sampling tubes at flow rates of approximately 50 mL/min. 7. Sampling methods used were consistent with previous samplin g events and the site QAPP (e.g., low flow rate, stabilization of parameters, field quality assurance/quality control).

S:\CONDATA\2000s\2049.04\Source Files\ 2012 Annual Report\Att B - Field\20121119 GwQFSS.xlsx Page 1 of 1 Sanborn, Head & Associates, Inc.

# ATTACHMENT C
ANALYTICAL LABORATORY DATA REPORT'**·:** 

# Eastern Ana l ytical , Inc.

. ser v ices P r 0 

### r, o
.**dr\\ \1(\** **~** e s

s ion a l 

### l a bo rat o ry ""

Tim White Sanborn , Head & Associates , Inc

. ( NH) 20 Foundry Street Concord , NH 03301
Subjec t: Laboratory Report

Eastern Analytical , Inc

. ID : 116211

Dear Mr

. White : Client Identification : LTG Londonderry , NH 

### I 2049

. 04 Date Received : 11/19/2012

Enclosed please find the laboratory report for the above identified project. All analyses were performed in accordance with our 

### QNQC Program. Unless otherwise stated , holding times , preservation techniques , container types , and sample conditions adhered to EPA Protocol. Samples which were collected by Eastern Analytical , Inc

. (EA I ) were collected in accordance with approved EPA procedures. E astern Analytical , Inc

. certifies that the enclosed test results meet all requirements of NELAP and other applicable state certifications

. Please refer to our website at www

. ea i labs

. com for a copy of our NELAP certificate and accredited parameters

. The following standard abbreviations and conventions apply to all EA I reports: Solid samples are reported on a dry weight basis , unless otherwise noted
< : 

### " less than " followed by the reporting limit
> : 

### " greater than " followed by the reporting limit % R : % Recovery

Eastern Analyt i cal Inc. maintains certification in the following states : Connecticut (PH

- 0492) , Maine (NHOOS) , Massachusetts (M

- NHOOS) , New Hampshire/NELAP (1012), Rhode Island (269) and Vermont (VT1012)

. The following information is contained within this report : Sample Conditions summary, Analytical Results/Data , Quality Contro l data (if requested) and copies of the Chain of Custody

. This report may not be reproduced except in full , without the the written approval of the laboratory

. If you have any questions regarding the results conta i ned within , please feel free to d i rectly contact me or the chemist(s) who performed the testing i n question

. Unless otherwise requested , we will dispose of the sample(s) 30 days from the sample receipt date

.
We appreciate this opportunity to be of service and look forward to your continued patronage

. Sincerely ,



# 10 Lorraine Olashaw , Lab Director #of pages (excluding cover letter)



### 25 C h e n e ll Dr i ve 

## I Concord , NH 

### 0330 I 

## I 800

. 287

. 0525 

## I www.e ai l a bs.co m

# ' SAMPLE CONDITIONS PAGE

Client: Sanborn , Head & 

### Associates, Inc. (NH) Client Designation: LTG Londonderry, NH / 2049.04 

## EAIID# : 116211

Temperature upon r ece ipt ( ° C) : 

## 4 Acceptable temperature range ("C): 0-6 

### Received on ice or co ld packs (Yes / No): 

## y

Date Date Sample% Dry Lab ID Samp l e ID Received Sampled Matrix Weight Excep ti ons/Comments {other than thermal preservation) 116211

. 01 MW -2 R /11-19-12 11/19/12 11/19/12 aqueous Adheres to Sample Acceptance Policy
116211

. 02 MW-60

- 2/11

- 19-12 11/19/12 11/19/12 aqueous Adheres to Sample Acceptance Policy
116211

. 03 MW

- 60-4/11-19

- 12 11/19/12 11/19/12 aqueous Adheres to Sample Acceptance Policy
116211

. 04 DUP-1/11-19-12 11/19/12 11 /19/12 aqueous Adheres to Samp l e Acceptance Policy
116211

. 05 Trip Blank 8260/11-19-12 11/19/12 11/6/12 aqueous Adheres to Sample Acceptance Policy
116211

. 06 Trip Blank 1,4 Dioxane /11-19 11/19/12 11/1/12 aqueous Adheres to Sample Acceptance Po l icy -12

Samples were properly preserved and the pH measured when applicable unless otherwise noted. Analysis of solids for pH, Flashpoint, lgnitibility , Paint Filter, Corrosivity , Conductivity and Specific Gravity are reporled on an "a s received" basis. All results contained in this report relate only to the above fisted samples. References include : 1) EPA 600/4-79-020 , 1983 2) Standard Methods for Examination of Water and Wastewater: lnorganics , 19th Edition, 1995 ; Microbiology , 20th Edition, 1998 3) Test Methods for Evaluating Solid Waste SW 846 3rd Edition including updates IVA and IVB 4) Hach Water Analysis Handbook, 2nd edition, 1992


### Eastern Analytical, Inc

. www.eailabs

. com 1800.287

. 0525 1 customerservice@eailabs.com 

## 1

# L A BORA T O R Y REPORT

•
' 

## EAIID# : 

## 116 2 11 Client: Sanborn , H ead 

### & Associates , I n c. ( N H) Client Designation : LTG Londo n derry, N H /2049. 0 4
Sample ID : MW-2R /11-19 -12 MW-6D-2/11 MW-6D-4/ DUP-1/11 Trip Blank -19-12 11-19-12 -1 9-12 8260 I 

### 11-19 -12 Lab Sample I D : 116211.01 116211 .02 116211

. 03 116211 .04 116211.05 Matr i x : aqueous aqueous aqueous aqueous aqueous Date Sampled: 11/19/12 11/19/12 11/19/12 11/19/12 11 /6/12 Date Received : 11/19/12 11/19/12 11/19/12 11/19/12 11/19/12 Units: ug/1 ug/ 1 ug/1 ug/1 ug/1 Date of Analysis : 11/21/12 11/2111 2 11 /21112 1 1/21/ 12 11/21/12 Analyst: BAM BAM BA M BAM BAM Method : 8260B 8260B 82608 8260B 82608 Dilution Factor: 1
Dichlorodifluoromethane <5 <5 <5 <5 <5 Chloromethane <2 <2 <2 <2 <2 Vinyl chloride <2 <2 <2 <2 <2 8romomethane <2 <2 <2 <2 <2 Chloroethane <5 <5 <5 <5 <5 T richlorofl uoromethane <5 <5 <5 <5 <5 Oiethyl Ether <5 <5 <5 <5 <5 Acetone <10 < 10 < 10 < 10 < 10 1,1-0ichloroethene 

### 4 < 1 < 1 < 1 < 1 tert-Butyl Alcohol (TBA) <30 < 30 < 30 < 30 < 30 Methylene chloride <5 <5 <5 <5 <5 Carbon disulfide <5 <5 <5 <5 <5 Methyl-t-butyl ether(MTBE) <5 <5 <5 <5 <5 Ethyl-t-butyl ether(ETBE) <5 <5 <5 <5 <5 Isopropyl ether(OIPE) <5 <5 <5 <5 <5 tert-amyl methy l ether(T AME) <5 <5 <5 <5 <5 trans-1 ,2-0 ichloroethene <2 <2 <2 <2 <2 1 , 1-0ichloroethane 7 

### 4 

### 3 4 <2 2,2-0ichloropropane <2 <2 <2 <2 <2 cis

- 1,2

- 0ichloroethene <2 <2 <2 <2 <2 2-8u t anone( M E K) < 10 < 10 < 10 < 10 <10 Bromoch l oromethane <2 <2 <2 <2 < 2 T etrahydrofuran(TH F) < 10 <10 < 10 < 10 < 10 Chloroform <2 <2 <2 <2 <2 1 , 1 ,1- Trichloroethane <2 <2 <2 <2 <2 Carbon tetrachloride <2 <2 <2 <2 <2 1 , 1 -D ichloropropene <2 <2 <2 <2 <2 Benzene < 1 < 1 < 1 < 1 < 1 1,2-0ichloroethane <2 <2 <2 <2 <2 T rich loroethene <2 <2 <2 <2 <2 1,2-0ichloropropane <2 <2 <2 <2 <2 Oibromomethane <2 <2 <2 <2 <2 Bromodichloromethane < 0.5 < 0

. 5 < 0

. 5 < 0

. 5 < 0.5 1 , 4-0ioxane <50 <50 <50 <50 <50 4-Methyl

- 2

- pentanone(MIBK) < 10 < 10 < 10 <10 < 10 cis-1,3-0ichloropropene <2 <2 <2 <2 <2 Toluene < 1 2 

### 1 2 

### < 1 trans-1 ,3-0ichloropropene <2 <2 <2 <2 <2 1 , 1 ,2-Trichloroethane <2 <2 <2 <2 <2 2-Hexanone <10 <10 < 10 < 10 < 10 Tetrachloroethene <2 <2 <2 <2 <2 1 ,3-0ichloropropane <2 <2 <2 <2 <2 Dibromochloromethane <2 <2 <2 <2 <2 1 ,2-0ibromoe th ane(EOB) <2 <2 <2 <2 < 2 Ch l orobe n zene <2 <2 <2 <2 <2 1,1 , 1 ,2-Tetrac hlor oethane <2 <2 <2 <2 < 2 Ethylbenzene < 1 < 1 < 1 < 1 < 1 Eastern A n a l ytical , In c. www.eailabs .co m 1 

### 800

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## 2

.-:**~** 

# LABORATORY REPORT



# .. EAIID#: 

## 116211 fi Client: Sanborn, Head 

### & Associates , Inc

. (NH) Client Designation: LTG Londonderry, NH 

### I 2049

. 04
Sample ID: MW -2R /11

- 19-12 MW -60-2 /11 MW -60 -4/ DUP-1/11 Trip B l ank -19-12 11

- 19-12 -19-12 8260 I 11 -19 -12 lab Sa mple ID: 116211.01 116211

. 02 116211

. 03 116211.04 116211

. 05 M a tr ix: aqueous aqueous aqueous aqueous aqueous Da te Sample d : 11/19/12 11 / 19/12 11/19/12 11/19/12 11 /6/ 12 Date Received: 11/19/12 11/19/12 11/19/12 11/19/12 11/19/12 U nits: ug/1 ug/1 ug/1 ug/1 ug/1 Date o f Analysis : 11/21/12 11/21/12 1 1 /21/12 11121/12 11/21 /12 Analyst: BAM BAM BAM BAM BAM M e thod : 8260 B 8260B 8260B 8260B 8260B Dilution Fa cto r: mp-Xylene < 1 < 1 < 1 < 1 < 1 o - Xylene < 1 < 1 < 1 < 1 < 1 Styrene < 1 < 1 < 1 < 1 < 1 Bromoform <2 <2 <2 <2 <2 IsoPropyl benzene < 1 < 1 < 1 <1 < 1 Bromobenzene <2 <2 <2 <2 <2 1,1 ,2,2-Tetrachloroetha ne <2 <2 <2 <2 <2 1 ,2 ,3- Trich l oropropane <2 <2 <2 <2 <2 n-Propylbenzene < 1 < 1 < 1 < 1 <1 2

- Ch l oroto l uene <2 <2 <2 <2 <2 4

- Ch l oroto l uene <2 <2 <2 <2 <2 1 , 3,5

-Trimethylbenzene < 1 < 1 < 1 < 1 < 1 tert

- Butylbenzene < 1 < 1 < 1 < 1 < 1 1 , 2 , 4

- Trimethylbenzene < 1 < 1 < 1 < 1 < 1 sec-Butyl benzene < 1 < 1 < 1 <1 < 1 1 ,3-Dic hlorobenzene <1 < 1 < 1 <1 < 1 p -lso propyltoluene < 1 < 1 <1 < 1 < 1 1 ,4 -0ic hlorobenzene < 1 < 1 <1 < 1 < 1 1 ,2

- 0ichlorobenzene < 1 < 1 <1 < 1 < 1 n - Butylbenzene <1 < 1 < 1 < 1 <1 1 ,2

- 0ibromo-3-ch l orop r opane <2 <2 <2 <2 <2 1 ,3,5- Trichlorobenzene < 1 < 1 < 1 < 1 < 1 1 , 2,4

- Trichloroben z ene < 1 < 1 < 1 < 1 < 1 Hexachlorobutadiene < 0.5 < 0

. 5 < 0.5 < 0

. 5 < 0.5 Naphthalene <5 <5 <5 <5 <5 1 , 2 ,3-T richlorobenzene < 1 < 1 < 1 < 1 < 1 4 -Bromo fluorobenzene (surr) 100 %R 101 % R 101 % R 100 %R 100 % R 1 , 2 -Dic hlorobenzene-d4 (s urr ) 113 % R 115 %R 116 % R 113 % R 115 %R Toluene-dB ( surr) 94%R 95% R 94%R 94%R 95%R

Eastern Analytical , In c. www

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## I customerservice@eailabs

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## 3

# QC REPORT

EAI ID #: 116211 Client: 

### Sa nborn , Head & 

### A ssoc i ates, In c

. ( NH) Client Designation : 

### L TG L on don derry , NH / 2 0 49.0 4

P ar amete r N ame B l a n k 

### L CS L CS D Ana l ysis Date Un i ts Li m i t s RPD M et h o d

Dichlorodifluoromethane < 5 Chloromethane < 2 Viny l chlo r ide < 2 Bromomethane < 2 Chloroethane < 5 Trichlorof l uoromethane < 5 Oiethyl Et h er < 5 Acetone < 10 1,1-Dichloroethene < 1 tert-Butyl Alcohol (TBA) < 30 Methylene chloride < 5 Carbon disu l fide < 5 Methy l

- t

- butyl e t her(MTBE) < 5 Ethyl

- t

- buty l ether(ET8E) < 5 Isopropyl ether(DIPE) < 5 tert-amyl methy l ether(TAME) < 5 trans-1 , 2-Dichloroethene < 2 1,1-Dichloroethane < 2 2 , 2

- Dichlo r opropane < 2 cis-1 , 2-Dichloroethene < 2 2-Butanone(MEK) < 10 Bromochloromethane < 2 Tetrahydrof u ran(THF) < 10 Chloro f orm < 2 1,1 , 1-Trich l oroethane < 2 Carbon tetrach l oride < 2 1 , 1-Dichloropropene < 2 Benzene < 1 1 , 2-Dichloroethane < 2 Trichloroethene < 2 1 , 2-Dichloropropane < 2 Dibromomethane < 2 Bromodich l oromethane < 0

. 5 1 ,4-Dioxane < 50 4-Methyl-2-pentanone(M I 8K) < 10 cis-1 ,3-Dich l oropropene < 2 Toluene < 1 trans-1 ,3-Dichloropropene < 2 1 , 1 , 2

- Trichloroethane < 2 2-Hexanone < 10 Tetrachloroethene < 2 1 ,3-Dich l oropropane < 2 Dibromoch l oromethane < 2 1 ,2-Dibromoethane(ED8) < 2 Chlorobenzene < 2 1,1 , 1,2- Tetrachloroethane < 2 

### Eas te rn A nal y ti ca l , In c. 29 (143 %R) 27 (135 %R) (6 RPD) 11/20/2012 ug/1 40- 160 20 22(110%R) 20(102%R)(8RPD) 11/20/2012 ug/1 40-160 20 26(130%R) 25(126%R)(3RPD) 11/20/2012 ug/1 70

- 130 20

14 (71 %R) 16 (80 %R) ( 1 2 RPD) 11/20/2012 ug/ 1 40- 160 20 25 (126 %R) 24 (121 %R) (4 RPD) 11/20/2012 ug/ 1 70-130 20 * 28 (142 %R) * 27 (135 %R) (5 RPD) 11/20/20 1 2 ug/1 70

- 130 20

23 (115 %R) 23 (114 %R) (1 RPD) 11/20/2012 ug/ 1 70

- 130 20 20 (118 %R) 20 (117 %R) (1 RPD) 11/20/2012 ug/1 40

- 160 20 22 (1 09 %R) 2 1 (1 06 %R) (3 RPD) 1 1 /20/2012 ug/1 70

- 130 20

90(94%R) 100(101%R)(7RPD) 1 1 /20/2012 ug/ 1 70

- 130 20 23(114%R) 22(110%R)(4RPD) 11/20/2012 ug/1 70-130 20 23 (113 %R) 22 (1 08 %R) (5 RPD) 11/20/2012 ug/1 70

- 130 20 22 (1 08 %R) 22 (1 08 %R) (0 RPD) 11/20/2012 ug/1 70

- 130 20 2 1 (106%R) 2 1 (106%R)(ORPD) 11/20/2012 ug/1 70

- 130 20 21 ( 1 03 %R) 20 (1 02 %R) (1 RPD) 11/20/2012 ug/1 70

- 130 20 21 (103 %R) 20 (102 %R) (1 RPD) 11/20/2012 ug/1 70- 130 20 2 1 ( 1 07%R) 2 1 (104%R)(3RPD) 11/20/2012 ug/1 70-130 20 22(112%R) 21 (107%R)(5RPD) 11/20/2012 ug/1 70

- 130 20

16(80%R) 15(77%R)(4RPD) 1 1/20/2012 ug/1 70-130 20 2 4 (122 %R) 23 (115 %R) (6 RPD) 11/20/2012 ug/1 70- 130 20

20 (96 %R) 20 (93 %R) (3 RPD) 11/20/2012 ug/1 40

- 160 20 21(107%R) 20(101%R)(6RPD) 1 1/20/2012 ug/1 70-130 20

20 (85 %R) 20 (85 %R) (0 RPD) 11/20/2012 ug/1 70- 1 30 20 24(119%R) 22(112%R)(6RPD) 11/20/2012 ug/1 70

- 1 30 20 24(121%R) 23(116%R)(4RPD) 1 1/20/2012 ug/ 1 70-130 20 26 (128 %R) 24 (122 %R) (5 RPD) 11/20/2012 ug/ 1 70

- 130 20 22(109%R) 21(104%R)(5RPD) 11/20/2012 ug/1 70

- 130 20 23(113%R) 21 (107%R)(5RPD) 11/20/2012 ug/ 1 70-130 20 24 (118 %R) 22 (112 %R) (5 RPD) 11/20/2012 ug/ 1 70- 130 20 21 (104%R) 20( 1 00%R)(4RPD) 11/20/2012 u g/ 1 70

- 130 20 21 (107%R) 21 ( 1 04%R)(3RPD) 11/20/2012 ug/1 70

- 130 20 22 (111 %R) 21 ( 1 07 %R) (4 RPO) 11/20/2012 ug/1 70-130 20 23 (117 %R) 22 (1 11 %R) (5 RPD) 11/20/2012 ug/1 70

- 130 20 <50 (96 %R) <50 (95 %R) (1 RPD) 11/20/2012 ug/1 40- 160 20

20 (96 %R) 20 (98 %R) (2 RPD) 11/20/2012 ug/1 40

- 160 20 23 (116 % R) 22 (1 1 2 %R) (4 RPD) 11/20/20 1 2 ug/1 70- 130 20

20 (98 %R) 19 (95 %R) (3 RPD) 11/20/2012 ug/1 70

- 130 20 20 (99 %R) 1 9 (97 %R) (2 RPO) 11/20/2012 ug/1 70

- 130 20 20 (98 %R) 19 (95 %R) {3 RPD) 11/20/2012 ug/1 70- 130 20 20 (95 %R) 20 (95 %R) (0 RPD) 11/20/2012 ug/1 40

- 160 20 21 (107%R) 21 (104%R)(3RPD) 11/20/2012 ug/1 70-130 20

19 (95 %R) 18 (92 %R) (3 RPD) 11/20/2012 ug/1 70

- 130 20 20 (1 00 %R) 20 (99 %R) (1 RPD) 11/20/2012 ug/1 70

- 130 20

18 (92 %R) 18 (91 %R) (1 RPD) 11/20/2012 ug/ 1 70-130 20 20 (98 %R) 19 (93 %R) (5 R PD) 11/20/2012 ug/1 70

- 130 20 22 ( 1 08 %R) 21 (104 %R) (4 RPO) 11/20/2012 ug/ 1 70-130 20 

### www.eailabs

. com 1 

### 800.287.0525 1 

### customerservice@eailabs.com 82608 82608 82608 82608 82608 82608 82608 82608 82608 82608 82608 82608 82608 82608 82608 82608 82608 82608 82608 82608 82608 82608 82608 82608 82608 82608 82608 82608 82608 82608 82608 82608 82608 82608 82608 82608 82608 82608 82608 82608 82608 82608 82608 82608 82608 82608 

## 4

### I



## . _ 

# QC REPORT

C l ient: Sa nborn , H ea d & 

### A s so c iat es, In c. ( NH ) C l ien t Designation : LT G Lon d ond e r ry, NH / 2049 .0 4

P aram e te r N a m e Bl an k L CS L CSD A n alysis D a te Unit s Ethy l benzene <1 21 (104%R) 20 (100 %R) (4 RPD) mp - Xy l ene < 1 41 (103 %R) 39 (98 %R) (5 RPD) o-Xy l ene < 1 20 (101 %R) 19 (97 %R) (4 RPD) Sty r ene < 1 21 (10 4 %R) 20 (98 %R) (6 RPD) Bromoform <2 18 (90 %R) 17 (87 %R) (3 RPD) lsoPropylbenzene < 1 22 (112 %R) 22 (108 %R) (4 RPD) Bromobenzene <2 18(90%R) 18 (88 %R) (2 RPD) 1 , 1 , 2,2- Tetrachloroethane <2 17 (87 %R) 17 (87 %R) (0 RPD) 1 , 2 , 3

- Trichloropropane <2 18(88%R) 1 7 (87 %R) (1 RPD)
n - Propylbenzene < 1 1 9 (96 %R) 19 (93 %R) (3 RPD) 2-Chlorotoluene <2 18 (91 %R) 19 (93 %R) (2 RPD) 4

- Chlorotoluene <2 19 (94 %R) 18 (89 %R) (5 RPD) 1 , 3 , 5- Trimethylbenzene < 1 19 (97 %R) 19 (93 %R) (4 RPD) tert-8utylbenzene < 1 19 (95 %R) 19 (93 %R) (2 RPD) 1 , 2,4- Trimethy l benzene < 1 19 (96 %R) 18 (92 %R) (4 RPD)
sec - 8utylbenzene < 1 19 (95 %R) 19 (93 %R) (2 RPD) 1 ,3

- Dich l orobenzene < 1 18(92%R) 1 8 (90 %R) (2 RPD) p - lsopropyltoluene <1 19 (97 %R) 19 (97 %R) (0 RPO) 1 A

- Dichlorobenzene < 1 18 (92 %R) 18 (90 %R) (2 RPD) 1 , 2

- Dichlorobenzene <1 18 (91 %R) 18 (90 %R) (1 RPD)
n - 8utylbenzene < 1 19 (94 %R) 18 (92 %R) (2 RPD) 1 , 2

- Dibromo

- 3

- chloropropane <2 15 (76 %R) 15 (76 %R) (0 RPD) 1 ,3,5- Trichlorobenzene < 1 18 (92 %R) 18 (92 %R) (0 RPD) 1 , 2,4

- Trichlorobenzene < 1 16 (80 %R) 1 6 (81 %R) (1 RPD) Hexachlorobutadiene < 0.5 16 (81 %R) 16 (80 %R) (1 RPD) Naphthalene <5 15 (73 %R) 15 (76 %R) (4 RPD) 1 , 2,3- Trichlorobenzene < 1 17 (84 % R) 17 (87 %R) (4 RPD) 4-8romofluorobenzene (surr) 100%R 112 %R 1 1 0 %R 1 , 2-Dichlo r obenzene

- d4 (s u rr) 11 1 %R 103%R 103%R Toluene-dB (surr) 95 %R 97%R 97%R



### Samples were extracted and analyzed within holding time limits. Instr u mentation was calibrated in accordance with t h e method requirements. The method blanks we r e f r ee of con t amina t ion at t he reporting limits

. Sample surroga t e recoveries met the above stated cri t eria. 11/20/20 1 2 11/20/2012 11/20/2012 11/20/2012 11/20/2012 1 1/20/2012 11/20/2012 11/20/2012 11/20/2012 11/20/2012 11/20/2012 11/20/2012 11/20/2012 11/20/2012 1 1/20/2012 1 1/20/2012 11/20/2012 11/20/2012 11/20/2012 11/20/2012 11/20/2012 11/20/2012 11/20/2012 11/20/2012 11/20/2012 11/20/2012 11/20/2012 11/20/2012 11/20/20 1 2 1 1 /20/20 1 2



### The associated matrix spikes and/or Laboratory Co n trol Samples met acceptance criteria. There were no exceptions in the analyses, un l ess no t ed

. ug/1 ug/1 ug/1 ug/1 ug/1 ug/1 ug/1 ug/1 ug/1 ug/1 ug/1 ug/1 ug/1 ug/1 ug/1 ug/1 ug/1 ug/1 ug/1 ug/1 ug/1 ug/1 ug/1 ug/1 ug/1 ug/1 ug/1 % Rec %Rec % Rec



### */! 

### Flagged ana l yte recoveries deviated f rom the QAJQC l imits. Any impact to data is addressed below

. 

## EA II D#: 116211

Lim i t s RP D M e th o d
70-130 20 82608 70

- 130 20 82608 70

- 130 20 82608 70

- 130 20 82608 70- 130 20 82608 70-130 20 82608 70- 130 20 82608 70- 130 20 82608 70- 130 20 82608 70

- 130 20 82608 70

- 130 20 82608 70

- 130 20 82608 70

- 130 20 82608 70

- 130 20 82608 70-130 20 82608 70-130 20 82608 70- 130 20 82608 70

- 130 20 82608 70

- 130 20 82608 70-130 20 82608 70- 130 20 82608 70- 130 20 82608 70- 130 20 82608 70- 1 30 20 8260 8 70

- 130 20 82608 70- 130 20 82608 70

- 130 20 82608 70

- 130 20 82608 70- 130 20 82608 70-130 20 82608



### E as tern A n a lytic a l , In c. www.ea i labs

. com 1 800

. 287

. 0525 1 custome r service@eailabs

. com 

## 5

# LABORATORY REPORT 

# • EAIID#: 116211 Client: 

### Sanborn, Head & 

### Associates, Inc. (NH) Client Designation: 

### LTG Londonderry, NH /2049.04
Sample ID : MW-2R /11-19-12 MW-60-2/11 MW-60-4/ OUP-1/11 Trip Blank -19-12 11-19-12

- 19-12 1,4 Dioxane I 

### 11-19-12 Lab Sample ID : 116211.01 116211.02 116211 .03 116211.04 116211.06 Matrix: aqueous aqueous aqueous aqueous aqueous Date Sampled: 11/19/12 11/19/12 11/19/12 11/19/12 11/1/12 Date Received: 11/19/12 11/19/12 11/19/12 11/19/12 11/19/12 Units: ug/1 ug/1 ug/1 ug/1 ug/1 Date of Analysis: 11/24/12 11/24/12 11/24/12 11/24/12 11/24/12 Analyst: 

### VG VG VG VG VG Method : 82608 SIM 82608 SIM 82608 SIM 82608 SIM 82608 SIM Dilution Factor: 1 1,4-Dioxane 0.35 0.35 0.28 0.40 < 

### 0.25 4-Bromofluorobenzene (surr) 100 %R 99%R 100 %R 99%R 99%R Toluene-dB (surr) 101 %R 91 %R 102 %R 91 %R 91 %R



### Eastern Analytical, Inc. www.eailabs.com 

### 1800 .287.0525 1 customerservice@eailabs.com 

# 6

# • QC REPORT

EAIID#: 116211 C l ient Sanborn, Head & 

### A ssoc iate s, Inc

. (NH) Client Designation: LTG Londond er ry , NH / 2049.04

Paramete r Nam e Blank LCS L CS D A naly s is Date Units Lim its RPD Method
1,4-Dioxane < 

### 0

. 25 4.3 (85 %R) 4

. 7 (94 o/oR) (10 RPD) 11/24/2012 ug/1 70

- 130 20 82608 4-Bromofluorobenzene (surr) 99%R 99%R 98 %R 11/24/2012 % Rec 70- 130 50 82608 Toluene-d8 (surr) 91 %R 90%R 101%R 11/24/2012 %Rec 70-130 50 82608



### Samples were extracted and analyzed within holding time limits

. Instrumentation was calibrated in accordance with the method requirements. The method blanks were free of contamination at the reporting limits

. Sample surrogate recoveries met the above stated criteria. The associated matrix spikes and/or Laboratory Control Samples met acceptance criteria

. There were no exceptions in the analyses , unless noted

. *!! Flagged analyte recoveries deviated from the QNQC limits

. Any impact to data is addressed below

.

Eastern Analytical , Inc. www.eailabs.com 1800.287

. 0525 1 customerservice@eailabs.com 

## 7

# LABORATORY REPORT

Eastern Analyti c al , Inc

. www

. ea il abs

. com 1 

### 800

. 287

. 0525 1 

### customerservice@eailabs

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# 8

# • QC REPORT

Client: Sanborn, Head & 

### Associates, Inc. (NH) Client Designation: LTG Londonderry, NH /2049.04

Date of Parameter Name Blank LCS LCSD Units Analysis
Antimony < 0.001 0

. 92 (92 %R) mg/L 11/26/12 Arsen i c < 0

. 001 0

. 96 (96 %R) mg/L 11 /26/12 Barium < 0

. 001 0.91 (91 %R) mg/L 11/26/12 Beryllium < 0.001 1.0(103%R) mg/L 11/26/12 Chromium < 0

. 001 0.89 (89 %R) mg/L 11/26/12

MS/MSD MS/MSD Date of Parameter Name Parent ID Parent Matrix Spike MSD Units Analysis
Antimony 116260

. 01 < 0.001 1 .0 (100 %R) 1

. 0 (1 00 % R) (0 RPD) mg/L 11/26/12 Arsenic 116260

. 01 < 0

. 001 1

. 0 ( 101 %R) 1

. 0 (1 01 %R) (0 RPD ) mg/L 11/26/12 Barium 116260.01 0

. 007 0

. 98 (98 %R) 0

. 98 (97 %R) (1 RPD) mg/L 11/26/12 Beryllium 116260

. 01 < 0

. 001 1

. 1 (11 0 %R) 1

. 1 (109 %R) (1 RPD) mg/L 11/26/12 Chromium 116260.01 < 0.001 0.93 (93 %R) 0

. 94 (94 %R) (1 RPD) mg/L 11/26/12

Samples were analyzed within holding times unless noted on the sample results page. Instrumentation was calibrated in accordance with the method requ irements

. The method blanks were free of contamination at the reporting limits. The associated matrix spikes and/or Laboratory Control Samples met the above stated criteria. Exceptions to the above statements are flagged or noted above or on the QC Narrative page. */! Flagged analyte recoveries deviated from the QAIQC limits. 

## EAIID#: 116211

Limits RPD Method

80- 120 20 6020 80- 120 20 6020 80- 120 20 6020 80- 120 20 6020 80- 120 20 6020

Limits RPD Method

75 -125 20 6020 75-125 20 6020 75 -1 25 20 6020 75-125 20 6020 75-125 20 6020



### Eastern Analytical, Inc. www.eailabs

. com 1800.287

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## I customerservice@eailabs

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## 9

### CHAIN-OF-CU S TOD Y RECORD 

### Page of

__ _ BoLD FIELDS REQUIRED. PLEASE CI RCL E REQUE STED ANAL Ys is

. SS U IUS U

S A M P LE 

## 1.0. SAMPLING DATe/TIME 

## *IF C OMPOSITE, IN DICATE Bo TH START 

### & F IN I SH .T E / T I ME

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### NPDES: RGP POTW STORHWATER OR 

### GWP, OIL fUND, BROWNFIELD OR OTHER : --------- QUOTE 

## #: PO 

### #:

_______ _ DATE NE EDED: 

### QAI QC REPORTING lEVEL



## A 

# 4)

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# 5

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PRESUMPTIVE CERTAINTY

RELINQUISHED BY: DATE:
RELINQUISHED B Y: DATE: 

### ..... 0 0 

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# ~0

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### 13 PP F E , M N 

### PB, Cu
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# S"b, A.s , JS..._, 

# ge. C-

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. ' SAMPLES fiELD fiLTERED? 

# 0 YES 

# 0 No NOTES: (IE: SPECIAL DETECTION LIMITS , BILLING INFO, IF DIFFERENT)

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___ ____ ___ _ SUSPEOED (ONTAHINATION:

__ ___ __ _ fiELD READ IN GS:

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# ~Jut**~** 25 CHENELL Druve 

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# ATTACHMENT D DATA QUALITY/DATA USABILITY ASSESSMENT

# A TTACHMENT 

# D D ATA 

# Q UALITY 

# /D ATA 

# U SABILITY 

# A SSESSMENT Sanborn Head performed an assessment of data quality and usabil ity as described in Sanborn Head’s December 2009 Quality Assurance Project Plan 1 

## (QAPP; Refer to Tables D-1 and D-2).

 

## A review of field equipment calibration/calibration check data sheets indicated that the field instruments used for the November 2012 groundwater monito ring event were calibrated correctly and maintained calibration throughout the day within the criteria established in the QAPP with the following exception:

 

## The QAPP recommends the specific conductivity probe be calibrat ed with a conductivity solution, and the calibration check completed with a second standard to check the linearity of the instrument. We note the specific conductance probe was calibrated with a single standard (1,413 μS/cm), and that the s tandard was generally lower than the specific conductance values typically measured in the monitoring points at the site (approximately 3,000

– 13,000 μS/cm). Specific conductance is one of the ground water parameters used to assess stabilization (e.g., based on relative measurements), which was achieved at each loc ation prior to sample collection. Therefore, the specific conductance calibrat ion procedure used in 2012 is not anticipated to affect the laboratory data quality o r usability (e.g., comparison to groundwater standards/criteria).

 

## A review of the analytical data packages provided by the labora tory indicated the following:

 

## Laboratory data packages were complete.

 

## Laboratory Quality Control (QC) met the applicable criteria wit h the following exceptions:

 

## The laboratory control sample (LCS) for trichlorofluoromethane had a slightly high recovery (142%; acceptable range: 70-130%) in the 8260B an alysis. This indicates a potential high bias in the reporting limit for tric hlorofluoromethane; however, the reporting limit (5 micrograms per liter [μg/l]) wa s never exceeded and is much lower than the applicable groundwater standard (2,0 00 μg/l). Additionally, trichlorofluoromethane is not a compound of conce rn at this site.

 

## There were no analytes detected in the trip blanks.

1 

### Sanborn Head, December 2, 2009, Quality Assurance Project Plan and Work Plan for Groundwater and Surface Water Monitoring, Town Garage/Radio Beacon Site, London derry, New Hampshire, NHDES Site No. 198509001. The QAPP was initially submitted to USEPA in Aug ust 2009. The QAPP was subsequently revised in December 2009 based on comments by USEPA, and was ap proved on April 5, 2010.

### January 2013 Page 2 DQA-DUE.docx 2049.04

 

## The blind field duplicate groundwater sample pair (MW-6D-2/11-1 9-12 and Dup1/11-19-12) RPDs met acceptance criteria. The arsenic RPD betwe en concentrations measured in the primary and duplicate samples wa s 31% (1.1 μg/l in the primary sample vs. 1.5 μg/l in the duplicate sample); ho wever, in accordance with the QAPP, these results are accepted because they were les s than four times the reporting limit (1 μg/l).

 

## As noted in the QAPP, reporting limits for cis- and trans-1,3-d ichloropropene (reporting limit = 2 μg/l vs. AQGS = 0.5 μg/l), 1,2-dibromochloropropane ( [DBCP]; reporting limit = 2 μg/l vs. AQGS = 0.2 μg/l), and 1,2-dibromoethane ([ethylene dibromide]; reporting limit = 2 μg/l vs. AQGS = 0.05 μg/l) did not meet the AGQS/GW-1 Groundwater Standard; however, none of these analytes are compounds of conc ern at this site. Based on the data quality/data usability assessment, the data a re of sufficient quality for their intended purpose (i.e., comparison of concentrations repo rted for the site-specific analytes of concern to applicable groundwater standards).

S:\CONDATA\2000s\2049.04\Source Files\2012 Annual Report\Att D - DQA\DQA-DUE.docxTABLE D-1 Review of Analytical Reporting Limits, Trip Blank, and Duplicate % RPD – Groundwater Town Garage/Radio Beacon Site – Londonderry, New Hampshire NHDES Site No. 198509001

Concentrations in μ g/l. Trip Blank / 11-19-12 MW-2R / 11-19-12 MW-6D-4 / 11-19-12 MW-6D-2 / 11-19-12 Dup-1 / 11-19-12

11/6/2012 - VOCs

11/1/12 - 1,4-dioxane

by SIM 11/19/12 11/19/12 11/19/12 11/19/12

VOCs

AVOCs Benzene 71-43-2 5 2,000 <1 <1 <1 <1 <1

– Butylbenzene (n-) 104-51-8 260 † <1 <1 <1 <1 <1

– Butylbenzene (sec-) 135-98-8 260 † <1 <1 <1 <1 <1

– Butylbenzene (tert-) 98-06-6 260 † <1 <1 <1 <1 <1

–

Ethylbenzene 100-41-4 700 3,000 <1 <1 <1 <1 <1

– Isopropylbenzene (Cumene) 98-82-8 800 NA <1 <1 <1 <1 <1

–

Isopropyltoluene (p-) 99-87-6 260 † <1 <1 <1 <1 <1

–

Naphthalene 91-20-3 20 2,000 <5 <5 <5 <5 <5

– Propylbenzene (n-) 103-65-1 260 † <1 <1 <1 <1 <1

– Styrene 100-42-5 100 50,000 <1 <1 <1 <1 <1

– Toluene 108-88-3 1,000 50,000 <1 <1 1 2 2 0% Trimethylbenzene (1,2,4- ) 95-63-6 330 3,000 <1 <1 <1 <1 <1

– Trimethylbenzene (1,3,5- ) 108-67-8 330 NS <1 <1 <1 <1 <1

– Xylene (m,p-) 108-38-3 106-42-3 NS NS <1 <1 <1 <1 <1

– Xylene (o-) 95-47-6 NS NS <1 <1 <1 <1 <1

– Total Xylenes 1330-20-7 10,000 30,000 ND ND ND ND ND

– CVOCs Carbon Tetrachloride 56-23-5 5 40 <2 <2 <2 <2 <2

– Chlorobenzene (Monochloroben zene) 108-90-7 100 2,000 <2 <2 <2 <2 <2

– Chloroethane 75-00-3 NS NS <5 <5 <5 <5 <5

– Chloroform (Trichloromethane) ¢ 67-66-3 70 100 <2 <2 <2 <2 <2

– Chloromethane 74-87-3 30 † <2 <2 <2 <2 <2

– Chlorotoluene (2-) 95-49-8 100 † <2 <2 <2 <2 <2

– Chlorotoluene (4-) 106-43-4 NS NS <2 <2 <2 <2 <2

– Dichlorobenzene (1,2-) 95-50-1 600 20,000 <1 <1 <1 <1 <1

– Dichlorobenzene (1,3-) 541-73-1 600 † <1 <1 <1 <1 <1

– Dichlorobenzene (1,4-) 106-46-7 75 50,000 <1 <1 <1 <1 <1

– Dichloroethane (1,1-) 75-34-3 81 10,000 <2 7 3 4 4 0% Dichloroethane (1,2-) 107-06-2 5 300 <2 <2 <2 <2 <2

– Dichloroethene (1,1-) 75-35-4 7 1,000 <1 4 <1 <1 <1

– Dichloroethene (cis-1,2-) 156-59-2 70 NA <2 <2 <2 <2 <2

– Dichloroethene (trans-1,2-) 156-60-5 100 1,000 <2 <2 <2 <2 <2

–

Dichloropropane (1,2-) 78-87-5 5 200 <2 <2 <2 <2 <2

– Dichloropropane (1,3-) 142-28-9 NS NS <2 <2 <2 <2 <2

– Dichloropropane (2,2-) 594-20-7 NS NS <2 <2 <2 <2 <2

– Dichloropropene (1,1-) 563-58-6 NS NS <2 <2 <2 <2 <2

– Dichloropropene (cis-1,3-) 10061-01-5 0.5 * ‡ † <2 <2 <2 <2 <2

– Dichloropropene (trans-1,3-) 10061-02-6 0.5 * ‡ † <2 <2 <2 <2 <2

–

Hexachlorobutadiene 87-68-3 0.5 † <0.5 <0.5 <0.5 <0.5 <0.5

– Methylene Chloride ( Dichloromethane) 75-09-2 5 1,000 <5 <5 <5 <5 <5

– Tetrachloroethane ( 1,1,1,2-) 630-20-6 70 † <2 <2 <2 <2 <2

– Tetrachloroethane (1,1,2,2- ) 79-34-5 2 1,000 <2 <2 <2 <2 <2

– Tetrachloroethene (PCE) 127-18-4 5 80 <2 <2 <2 <2 <2

– Trichlorobenzene (1,2,3- ) 87-61-6 NS NS <1 <1 <1 <1 <1

– Trichlorobenzene (1,2,4- ) 120-82-1 70 1,000 <1 <1 <1 <1 <1

– Trichlorobenzene ( 1,3,5-) 108-70-3 40 † <1 <1 <1 <1 <1

– Trichloroethane (1,1,1-) 71-55-6 200 50,000 <2 <2 <2 <2 <2

– Trichloroethane (1,1,2- ) 79-00-5 5 500 <2 <2 <2 <2 <2

– Trichloroethene (TCE) 79-01-6 5 100 <2 <2 <2 <2 <2

– Trichloropropane ( 1,2,3-) 96-18-4 40 † <2 <2 <2 <2 <2

– Vinyl Chloride 75-01-4 2 10 <2 <2 <2 <2 <2

– Other VOCs Acetone 67-64-1 6,000 † <10 <10 <10 <10 <10

– Bromobenzene 108-86-1 NS NS <2 <2 <2 <2 <2

– Bromochloromethane 74-97-5 NS NS <2 <2 <2 <2 <2

– Bromodichloromethane ¢ 75-27-4 0.6 NA <0.5 <0.5 <0.5 <0.5 <0.5

– Bromoform ¢ 75-25-2 4 2,000 <2 <2 <2 <2 <2

– Bromomethane 74-83-9 10 10 <2 <2 <2 <2 <2

– Butanone (2-) (MEK) 78-93-3 4,000 50,000 <10 <10 <10 <10 <10

–

Carbon Disulfide 75-15-0 70 † <5 <5 <5 <5 <5

– Dibromo-3-chloropropane (1,2-) (DBCP) # 96-12-8 0.2 † <2 <2 <2 <2 <2

– Dibromochloromethane ¢ 124-48-1 60 NA <2 <2 <2 <2 <2

– Dibromoethane (1,2-) (Ethyle ne dibromide) 106-93-4 0.05 700 <2 <2 <2 <2 <2

–

Dibromomethane (Methylene bromide) 74-95-3 NS NS <2 <2 <2 <2 <2

– Dichlorodifluoromethane 75-71-8 1,000 † <5 <5 <5 <5 <5

– Diethyl Ether (Ethyl Ether) 60-29-7 1,400 † <5 <5 <5 <5 <5

– Diisopropyl ether (DIPE) 108-20-3 120 † <5 <5 <5 <5 <5

– Dioxane (1,4-) 123-91-1 3 † <50 <50 <50 <50 <50

– Dioxane (1,4-) 123-91-1 3 † <0.25 0.35 0.28 0.35 0.40 13% Ethyl tertiary butyl ether (ETBE) 637-92-3 40 † <5 <5 <5 <5 <5

– Hexanone (2-) 591-78-6 NS NS <10 <10 <10 <10 <10

– Methyl-2-pentanone (4-) (MIB K) 108-10-1 2,000 50,000 <10 <10 <10 <10 <1 0

– Methyl-t-butyl Ether (MTBE) 1634-04-4 13 10,000 <5 <5 <5 <5 <5

– Tertiary amyl methyl e ther (TAME) 994-05-8 140 † <5 <5 <5 <5 <5

– Tertiary butyl alcohol (TBA) (tert-Butanol) 75-65-0 40 † <30 <30 <30 <30 <30

– Tetrahydrofuran 109-99-9 154 † <10 <10 <10 <10 <10

– Trichlorofluoromethane 75-69-4 2,000 † <5 <5 <5 <5 <5

– Total Metals Antimony 7440-36-0 6 NA <2 <2 <2 <2

– Arsenic 7440-38-2 10 NA 1.0 0.6 1.1 1.5 31% Barium 7440-39-3 2,000 NA 370 240 220 220 0% Beryllium 7440-41-7 4 NA <2 <2 <2 <2

– Chromium 7440-47-3 100 NA <2 4 <2 <2

– Analyte CAS Nos. GW-1 (AGQS) GW-2 Duplicate % RPD

Notes: 1. Samples were collected by Sanborn Head on the dates indicat ed and analyzed by Eastern Analytical, Inc. (EAI) of Concord, N ew Hampshire for volatile organic compounds (VOCs) by United St ates Environmental Protection Agency (USEPA) Methods 8260B and 8260B in selective ion monitoring (SI M) mode (low level 1,4-dioxane only), and total (unfiltered) me tals by USEPA Method 6020. 2. "<" indicates the analyte was not detected above the indica ted laboratory reporting limit. 3. "GW -1" and "GW-2" Groundwater Standards are from the New Hampshire Department of Environmental Services (NHDES) Contaminated Site s Risk Characterization and Management Policy (RCMP) (January 1 998, with 2000 through 2007 revisions/addenda). In addition, the June 2009 and July 2011 versions of Table 1 in the NHDES Vapor Intrusion Guidance inclu ded updates to some GW-2 Groundwater Standards which have been included in this table. GW-1 Groundwater Standards are equivalent to the Ambient Groundwater Quality St andards (AGQSs) promulgated in Env-Or 600 (July 2008). "‡" indicates the value depicted is the revised AGQS which was rai sed in the July 2008 update to EnvOr 600 . The AGQS/GW-1 Groundwater Standards are intended to be prote ctive of groundwater as a source of drinking water. The GW-2 G roundwater Standards apply to groundwater as a potential source of indoor air contamination. 4. "AVOCs" are aromatic VOCs. "CVOCs" are chlorinated VOCs.

"†" indicates the RCMP lists as not currently available. "NA" indicates the RCMP lists as not applicable. "NS" indicates the analyte is not listed in the RCMP. "ND" indicates not detected. "*" indicates the standard shown is for 1,3-dichloropropene (no is omer specified). "#" indicates the standard shown is for dibromochloropropane (no i somer specified). "¢ " indicates the RCMP lists the AGQS for total trihalomethanes ( bromoform, bromodichloromethane, dibromochloromethane and chlor oform) shall be 80 μg/l if the groundwater is contaminated by c hlorinated water supplies. 5. Bold italic reporting limits do not meet the AGQS/GW-1 Groundwater Standar ds. However, these are not identified as compounds of concern at this site. Shaded values are detected concentrations. No detected concentration s exceed the AGQS/GW-1 or GW-2 Groundwater Standards. 6. Duplicate % RPD indicates the relative percent difference as calculated by the following formula: | Result1 - Result2 | / ((Result1 + Result2) / 2) * 100 7. "

– " indicates the RPD can not be calculated because one or both o f the results are non-detect. 8. Refer to Sanborn Head's December 2009 Quality Assurance Pro ject Plan for further details on data quality and data usability.

S:\CONDATA\2000s\2049.04\Source Files\2012 Annual Report\Att D - DQA\Att D Tbls.xlsx Page 1 of 1 Sanborn, Head & Associates, Inc.TABLE D-2Review of Analytical Laboratory QC – GroundwaterTown Garage/Radio Beacon Site – Londonderry, New HampshireNHDES Site No. 198509001LabBatchMatrix Analyses EBEBClean?TBTBClean?LabBlankSurrogates MS/MSD LCS/LCSDVOCsMethod8260B– –Trip Blank /11-6-12Yes CleanWithinacceptancecriteria–Trichlorofluoromethane LCS (142%R)/LCSD (135%R) high recovery(acceptable = 70-130%R)VOCsMethod8260B-SIM– –Trip Blank /11-1-12Yes CleanWithinacceptancecriteria–Within acceptance criteriaTotalMetals–– – –Clean– –Within acceptance criteriaEAI116211GWNotes:1. Abbreviations/Acronyms:EAI= Eastern Analytical, Inc.GW= groundwaterEB= equipment rinseate blank sampleTB= trip blank sampleMS = matrix spike sampleMSD = matrix spike duplicate sampleLCS= laboratory control sampleLCSD= laboratory control sample duplicate%R= percent recovery%RPD= relative percent difference"–"= not applicable2. Refer to Sanborn Head's December 2009 Quality Assurance Project Plan for further details on data quality and data usability.S:\CONDATA\2000s\2049.04\Source Files\2012 Annual Report\Att D- DQA\Att D Tbls.xlsxPage 1 of 1Sanborn, Head & Associates, Inc.