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ANGP Blasting Plan 1
Blasting Plan
for
Addison Natural Gas Project Vermont Gas Systems, Inc.
Addison County, Vermont Date: June 25, 2012
(AMENDED to include Certificate of Public Good Conditions, now included as Appendix 4)
Prepared By: CHA in association with Maine Drilling and Blasting, Inc.
ANGP Blasting Plan 2
Table of Contents
General
Pre-Blast Surveys
Blast Monitoring
Sequence of Blasting
Blasting Procedures
Blast Area Security and Warning Signals
Explosives
Blaster Qualifications
Blasting Personnel
Licenses and Permits
Blast Vibration
Blast Reports
Typical Blast Design
ANGP Blasting Plan 3
General Vermont Gas Services, Inc. (VGS) considers safety as the priority during all phases of blasting operations. We are knowledgeable of and will follow all local, state and federal regulations related to transportation and use of explosives. The project specifications and conditions have been reviewed. Details of procedures for pre-blast surveys, explosives use, blast security, monitoring and documentation are enclosed. All blasts will be matted. Pre-Blast Surveys/Notifications Pre-blast surveys and Water Quality/Flow Testing will be offered to all property owners that are within a 600 ft. radius from the blast site. Appropriate notices will be given and appointments arranged for those owners who desire a survey. Pre-blast surveys will be conducted by a qualified firm approved by VGS. Results of those surveys will be documented through video or still photographs and appropriate narration or written reports. Post blast surveys will be conducted shortly following blasting. A public information hearing shall be conducted one month prior to the commencement of blasting in each Town. VGS shall provide landowners and VGS shall utilize best efforts to notify tenants with one week written notice followed by twenty-four hour advance notice, including “door hangers”. Blast Monitoring All blasts will be monitored by a representative of a qualified firm approved by VGS who has been properly trained in the setup and use of seismic monitoring equipment. At least one seismograph will be in use at all times. Placement of monitoring equipment will be at the nearest structure to the blast site. Results of blast monitoring will typically be available before the next blast, usually immediately following a blast. Results can be reviewed and modifications can be made to the blast design for the next blast if necessary. Sequence of Blasting All blasting operations will be strictly coordinated with VGS’s on-site representative, and local Fire Departments. Emphasis will be on the safe and efficient removal of the rock existing on this project without impact to surrounding structures. Blasts will be developed so as to create adequate relief which will minimize ground vibrations and offer the greatest protection possible to the surrounding structures. Blasting Procedures 1. Blasting operations shall be conducted Monday through Friday between the hours of 9 a.m. to 4:30 p.m., except on
state holidays; and all blasting within 300-feet of roads and road crossings will be limited to the hours of 9 a.m. to 3 p.m .
2. Blasting cannot be conducted at times different from those announced in the blasting schedule except in emergency
situations, such as electrical storms or public safety required unscheduled detonation.
3. Warning and all-clear signals of different character that are audible within a range of one-quarter mile from the point of the blast shall be given. All persons within the permit area shall be notified of the meaning of the signals through appropriate instructions and signs posted. Access will be restricted within 300-feet of the point of the blast.
4. Access to blasting area shall be regulated to protect the public from the effects of blasting. Access to the blasting
area shall be controlled to prevent unauthorized entry before each blast and until the perimeter’s authorized representative has determined that no unusual circumstances exist after the blast. Access to and travel in or through the area can then safety resume.
ANGP Blasting Plan 4
5. Areas in which charged holes are awaiting firing shall be guarded, barricaded and posted, or flagged against
unauthorized entry.
6. All blasts shall be made in the direction of the stress relieved face previously marked out or previously blasted.
7. All stemming shall be minimum as specified using clean, dry 3/8” crushed stone.
8. Blasting mats shall be used for all blasts to prevent fly rock. Blast Security and Warning Whistles Each blast will be preceded by a security check of the affected area and then a series of warning whistles. Communications will be made with job site supervisors and local officials as required to ensure the safest possible operation. All personnel in the vicinity closest to the blast area will be warned. The warning whistles will follow the following sequence: 3 Long Whistles Blown – 5 Minutes to Blast 2 Long Whistles Blown – 1 Minute to Blast 1 Long Whistle Blown – All Clear No blast will be fired until the area has been secured and determined safe. The blast site will be examined by the blaster prior to the all clear signal to determine that it is safe to resume work. Explosives All explosives will be delivered to the job site on a daily basis. There will be no overnight storage on site. Only the amount of explosives required to perform the day’s work will be brought to the site. All explosives will be stored in approved magazines when not in use. Technical Data and MSDS sheets for all explosive products shall be provided to VGS before the commencement of any blasting operations. See Appendix 2. All blasting materials will be perchlorate free. Blaster Qualifications The blaster in charge of this project will be licensed in the State of Vermont and have received various amounts of training in the safe use and handling of explosives. All blasters must be familiar with all OSHA Regulations, State Regulations, and Federal Regulations regarding construction site safety, including transportation, use and handling of explosive materials. Weekly safety meetings are to be held on site by the General Contractor, with a record of that meeting returned to the VGS on-site representative. Blasting Personnel All basting operations shall be conducted by experienced, trained and competent persons who understand the hazards involved. Persons working with explosive materials shall: 1. Have demonstrated a knowledge of, and a willingness to comply with, safety and security requirements. 2. Be capable of using mature judgment in all situations.
ANGP Blasting Plan 5
3. Be of good physical condition and not addicted to intoxicants, narcotics, or other similar type of drugs.
4. The person(s) responsible for the explosives shall possess current knowledge of the local, State and Federal laws and regulations applicable to his work.
5. The person(s) responsible for the explosives shall have obtained a Certificate of Competency or a license as required
by State law.
Licenses and Permits The drilling and blasting contractor shall be fully licensed and insured for the transportation, use, and handling of explosives. Evidence of Insurance will be made available. Blasting permits, as required, will be obtained from the local authorities by the drilling and blasting contractor when blasting is about to begin. Blast Vibration Blast vibration will be monitored at the structure closest to the blast site. Vibration limits will follow industry limits as outlined in US Bureau of Mines (USBM) RI 8507 Appendix B. Blast designs will be modified as required to stay within the guidelines. Blasting operations will be modified accordingly when approaching buildings and utilities. Ground vibration peak particle velocity limits shall not exceed USBM Alternative Blasting Criteria (Appendix 1) * US Bureau of Mines (USBM) RI 8507 Appendix B Airblast overpressure level not to exceed 133 peak dB (linear) two Hertz high –pass system. All blasting shall be performed in accordance with all applicable laws and regulations including, but not limited to, the Vermont Occupational Safety and Health Administration regulations. Vermont has adopted by reference, Code of Federal Regulations (“CFR”) OSHA regulations regarding explosives and blasting, and CVR 24 050 013 (Secretary of State Rule Log #92-041) (Rules Pertaining to VOSHA- Process Safety Management of Highly Hazardous Chemicals; Explosives and Blasting Agents). Specifically, Vermont has incorporated by reference 29 CFR Part 1910.109 Explosives and Blasting Agents and 29 CFR Part 1910.119 Process Safety Management of Highly Hazardous Chemicals. Blast Reports Enclosed is a sample of a typical Blast Report (Appendix 3). This report will be filled out for each blast and copies supplied to VSG. Typical Blast Design Prior to commencing any blasting work, the General Contractor shall submit to VGS a blast design document. This document shall include as a minimum: hole sizes, depths, spacing and loading information. These designs are to be considered a good starting point. Modifications are usually made, if necessary, following the first blasts to meet control and seismic considerations.
ANGP Blasting Plan 6
Appendix 1 US Bureau of Mines (USBM) RI 8507 Appendix B
ANGP Blasting Plan 7
Appendix 2 MSDS Sheets
ANGP Blasting Plan 8
Appendix 3 Sample Blast Report
ANGP Blasting Plan 9
Appendix 4 In addition to complying with the Blasting Plan as required by CPG, VGS shall notify all municipalities and their school principals’ designee with one week’s advance written notice, followed by 24-hour advance notice (by telephone and/or electronic mail), of any blasting within 300 feet of roads used for regular school bus routes. VGS will also comply with BMP’s with ANR MOU. See attached.
Transportation
Land Development
Environmental
Energy S e r v i c e s
7056 US Route 7
Post Office Box 120
North Ferrisburgh, Vermont 05473
802.497.6100
Fax 802.425.7799
Memorandum To: VGS Addison Natural Gas Project –
Phase I / Project File Date: September 12, 2013
Project No.: 57563.00
From: Adam R. Crary, PWS, PWD;
Jeffrey A. Nelson Re: Addison Natural Gas Project – Phase I
Class II Wetland Bedrock Assessments
Vanasse Hangen Brustlin, Inc. (“VHB”) has prepared this memorandum to provide additional
information to the Vermont Department of Environmental Conservation (“VT DEC”) Wetlands
Program1 regarding the identification and mitigation of potential impacts due to blasting on
Class Two wetlands associated with Phase I of the Vermont Gas System Addison Natural Gas
Project (“ANGP” or “Project”). This information consists of an assessment of potential areas
where shallow bedrock is anticipated within Class II wetlands or wetland buffers proposed to
be temporarily impacted by trenching for pipeline placement, as well as providing typical
construction details indicating the methods used to prevent adverse impact to the hydrology of
these wetland features.
The potential occurrence of shallow bedrock was reviewed in order to ascertain the most
probable locations where rock blasting may occur within proposed Class II wetlands or
associated buffers. From this information, we have identified those locations on the Project
alignment where blasting for trenched pipe installation could result in secondary impacts to
wetland hydrology. Although VHB recommends that this analysis should focus on those
wetlands that support significant wetland function for surface or groundwater protection
[Vermont Wetland Rules (“VWR”) Function 5.2], at the request of the VT DEC Wetland
Program, all proposed Class II wetlands (including vernal pools) and buffers that the Project
crosses have been included in the analysis. The following sections describe the review methods
and provide a brief description of results.
METHODOLOGY
The Project proposes temporary impacts from trenching to proposed Class II wetlands
throughout both the approximately 42-mile transmission mainline as well as two distribution
1 The ANR-DEC Wetland Program review occurs both under Public Service Board Docket No. 7970 as well as the Project’s application for an Individual Vermont Wetland Permit.
VGS Addison Natural Gas Project – Phase I
Ref: 57563.00
Page 2 of 3
September 12, 2013
mainlines (to Vergennes and Middlebury, respectively). Due to the significant length of the
Project components as well as the number of proposed Class II wetlands where the lines would
be trenched, it is both infeasible and impractical to collect detailed geotechnical data for the
sites. Therefore, VHB’s review follows a step-wise process to identify those wetlands where
secondary impacts from blasting could result in indirect impacts to significant wetland
functions, including but not limited to the Ground and Surface Water Protection function as it
relates to groundwater discharge/recharge, and subsurface flow. This assessment process relies
not on detailed geotechnical survey information, but rather on information collected during
VHB’s wetland delineation/classification assessments as well as publically available information
on the potential presence of shallow bedrock. In order to determine the sites where such
indirect impacts from blasting may potentially occur, proposed Class II wetland sites are
selected where pipeline construction by trenching is proposed2.
Within this subset of Project wetlands, VHB further evaluated both the surficial geologic
mapping3 and the depth to shallow bedrock information4 that are both publically available.
From review of the selected wetland sites within the Project alignment, overlaid on these two
sources, it was determined that two shallow rock types could potentially occur:
1. “Boulders in clay” or “bedrock exposure” (from surficial geologic mapping
information), and
2. Shallow depth to bedrock (</= 60 inches) (from NRCS).
Using this information, VHB assessed the likelihood that bedrock (or significant shallow rock)
could be encountered within the group of wetlands identified. As presented on the attached
table, VHB has identified two types of potential occurrences where blasting would be expected
to be necessary, and defined as:
“Likely” – these are the wetland/buffer sites where there is either bedrock exposure or
shallow bedrock identified, and
“Potential” – these are the wetland/buffer sites where boulders in clay have been
identified. Should blasting be necessary to split large boulders and facilitate their
removal from locations that occur in clay deposits, such blasting would not be expected
to result in any indirect impacts to wetland hydrology through bedrock fracturing from
blast vibrations. However, VHB includes these sites in the analysis as blasting within
these wetlands could occur if such large boulders are encountered.
2 Sites with trenching less than 50 square feet (equivalent to 10 linear feet) within the wetland or buffer are not included as such trenching would be expected to result in minimal, if any, effect on wetland hydrology. 3 Source: Vermont ANR, the layer was digitized from the 1:62,500 15 minute series USGS quadrangle map sheets compiled by The Vermont Geological Survey 1956-1970. Last updated August 2008. 4 Source: Natural Resources Conservation Service (“NRCS”) County Soil Survey Data. Accessed through the Vermont Center for Geographic Information. Last updated December 2011.
VGS Addison Natural Gas Project – Phase I
Ref: 57563.00
Page 3 of 3
September 12, 2013
RESULTS
Based on the assessment methods described above, and the detailed analysis presented in the
attached table, there are nine Class II wetlands/ buffer sites proposed for temporary impacts
from trenching where it is considered likely that shallow bedrock will be encountered. This
analysis identifies approximately 2,500 square feet of wetland area and 5,100 square feet of
buffer area where blasting potential is likely. These wetlands/buffers are indicated on the
summary table provided on Page 3 of the Attachment.
CONCLUSION/DISCUSSION
The potential for indirect impact to wetlands could, in theory, be anticipated to include the
altering of fractures within underlying bedrock that supports this wetland function and thereby
allowing downward flow of surface water from the wetland. However this concern is
minimized given the small amount of shallow blasting anticipated in these areas as described
above, the small trench size (typically 5-feet below grade by 5 feet-wide) , and the fact that the
Project is generally located within a valley-bottom landscape position within the Champlain
Valley biophysical region, where upward rather than downward groundwater flow typically
predominates.
From VHB’s review, and in-lieu of detailed geotechnical survey data, we conclude that it is
likely the Project trenching activities for line placement may encounter shallow bedrock at nine
wetland/buffer locations where potential indirect impacts from fractures created by blasting
could occur. Although these sites represent a small area of the overall Project, Vermont Gas will
incorporate measures to avoid blasting effects on surface or groundwater hydrology into the
final EPSC plan, consisting of the installation of a horizontal bentonite plug at the base of the
trench and trench breaker through the portion of the wetland where blasting would occur. VHB
has also identified several wetlands where large boulders set in clay deposits may also require
blasting, but would not anticipate any indirect effects on wetland hydrology at these locations.
Given the above, VHB does not anticipate that there will be any significant indirect impacts to
wetland hydrology from blasting for the Project, and the proposed significant VWR functions,
notably Function 5.2, will be maintained within proposed Class II wetlands that would be
temporarily impacted by trenched pipeline placement during Project construction.
ATTACHMENT:
Representative schematic blasting trench sketches prepared by CHA, dated September 12,
2013.
Potential Shallow Bedrock Sites within Class II Wetlands, dated September 12, 2013
\\vtdata\projects\57563.00 vgs addison expansion\docs\memos\wetland bedrock\angp_wetland bedrock memo_091213_clean_2.docx
ATTACHMENT
NOTE:1. WITHIN WETLAND AREAS SPECIFIED IN ATTACHMENT TO VHBMEMORANDUM DATED 9/12/13, APPLY BENTONITE TRENCHBREAKER AND BENTONITE PLUG ALONG BASE OF TRENCH.
NOTE:TYPICAL OVER BLASTFRACTURE- 0' TO 6'FROM BOREHOLELOCATION DEPENDENTON GEOLOGICALCONDITIONS.SOURCE: MAINEDRILLING & BASTING
NOTE:CHARGE AND STEMMING WILLVARY BASED ON GEOLOGY.SOURCE: MAINE DRILLING &BLASTING
NOTE:PATTERN WILL VARY BASED ON GEOLOGY.SOURCE: MAINE DRILLING & BLASTING
6"
SEE NOTE 1
1
Permanent Trench Break or SandbagsN.T.S.
3 Permanent Trench Break Spacing GuidelineN.T.S.
4
NOTE:1. WITHIN WETLAND AREAS SPECIFIED INATTACHMENT TO VHB MEMORANDUM DATED9/12/13, APPLY BENTONITE TRENCHBREAKER AND BENTONITE PLUG ALONGBASE OF TRENCH.
SEE NOTE 1 SEE NOTE 1
2
Vermont Gas ‐ Addison Natural Gas Project ‐ Phase IChittenden and Addison Counties, VermontPotential Shallow Bedrock Sites Within Class II Wetlands and BuffersPrepared by VHBSeptember 12, 2013
27, 29 9 ANGP‐EPSC‐041 Williston 14 2012‐CM‐55 15.63* a, d 5.1, 5.4, 5.6 Class II 307 576 boulders in clay > 60 Potential
28 9 ANGP‐EPSC‐030 Williston 14 2012‐CM‐143 0.15* a 5.1 Class II 137 541 boulders in clay > 60 Potential
31, 32 10 ANGP‐EPSC‐043 Williston 15 2012‐CM‐75 1.03* a 5.1 Class II 149 874 boulders in clay > 60 Potential
32 10 ANGP‐EPSC‐044 Williston 15 2012‐CM‐76 1.31* a 5.1 Class II 629 836 boulders in clay > 60 Potential
34, 35 10 ANGP‐EPSC‐045 Williston 16 2012‐CM‐79 6.26* a, c, g 5.1, 5.2, 5.6, 5.10 Class II 198 1198 boulders in clay > 60 Potential
35, 36 11 ANGP‐EPSC‐024 Williston 17 2012/2013‐CM‐82 4.45* a 5.1, 5.4, 5.6 Class II 602 2049 boulders in clay > 60 Potential
37, 38 11 ANGP‐EPSC‐025 Williston 18 2012/2013‐CM‐97/98 6.05* a 5.1, 5.2, 5.4, 5.6 Class II 720 1481 boulders in clay > 60 Potential
39 11 ANGP‐EPSC‐036 Williston 18 2012‐CM‐175 0.21* a 5.1, 5.4 Class II 361 746 boulders in clay > 60 Potential
43 12 ANGP‐EPSC‐049 Williston 20 2012‐CM‐91 0.52* a 5.1 Class II 225 1241 bedrock exposure > 60 Likely
44 13 ANGP‐EPSC‐028 Williston 21 2012‐CM‐102 0.93* a,c 5.1, 5.10 Class II 258 846 boulders in clay > 60 Potential
0 192 10 Likely
456 761 > 60 Likely
46 14 ANGP‐EPSC‐021 St George 22 2012/2013‐CM‐106 0.84* a 5.1 Class II 0 391 boulders in clay > 60 Potential
46 14 ANGP‐EPSC‐038 St George 22 2012‐CM‐220 0.75 a 5.1 Class II 385 546 boulders in clay > 60 Potential
48 15 ANGP‐EPSC‐029 St George 24 2012‐CM‐111 1.43* a 5.1 Class II 774 1152 boulders in clay > 60 Potential
49, 50 16 ANGP‐EPSC‐069 St George 25 2012‐PW‐97 1.91* a, c 5.1, 5.10 Class II 1838 585 boulders in clay > 60 Potential
50 16 ANGP‐EPSC‐068 St George 25 2012‐PW‐96 0.81* a 5.1 Class II 0 444 boulders in clay > 60 Potential
51 17 ANGP‐EPSC‐055 Hinesburg 26 2012‐JB‐38 2.23* a 5.1, 5.2 Class II 0 647 boulders in clay > 60 Potential
52 17 ANGP‐EPSC‐039 Hinesburg 26 2012‐CM‐222 0.04 a 5.1 Class II 0 169 boulders in clay > 60 Potential
53, 54 17 ANGP‐EPSC‐054 Hinesburg 26 2012‐JB‐33/34/35 14.8* a,c 5.1, 5.2, 5.5, 5.4, 5.10 Class II 1805 1278 boulders in clay > 60 Potential
54 17 ANGP‐EPSC‐040 Hinesburg 26 2012‐CM‐232 0.05* a 5.1, 5.2 Class II 0 315 boulders in clay > 60 Potential
297 260 10 Likely
4104 1604 > 60 Potential
909 1111 bedrock exposure > 60 Likely
1598 4779 boulders in clay > 60 Potential
66 19 ANGP‐EPSC‐089 Hinesburg 27 2013‐AW‐CM‐9 0.38* a 5.1, 5.2, 5.4, 5.10 Class II 221 585 boulders in clay > 60 Potential
67 19 ANGP‐EPSC‐085 Hinesburg 27 2013‐AW‐CM‐10 1.02* a 5.1, 5.2, 5.4, 5.10 Class II 624 555 boulders in clay > 60 Potential
870 901 10 Likely
0 443 > 60 Potential
69 19 ANGP‐EPSC‐071 Hinesburg 29 2012‐RS‐20 0.13* a 5.1 Class II 0 767 bedrock exposure > 60 Likely
70, 71 20 ANGP‐EPSC‐046 Hinesburg 30 2012‐CM‐84 2.83* a 5.1, 5.2 Class II 0 59 boulders in clay 10 Likely
72 20 ANGP‐EPSC‐067 Hinesburg 30 2012‐PW‐84 0.1 a 5.1 Class II 2 983 boulders in clay > 60 Potential
73 21 ANGP‐EPSC‐066 Hinesburg 31 2012‐PW‐79 0.79* a 5.1, 5.2 Class II 608 585 boulders in clay > 60 Potential
74 21 ANGP‐EPSC‐065 Hinesburg 31 2012‐PW‐78/RS‐18 1.4* a 5.1 Class II 1090 510 boulders in clay > 60 Potential
75 21 ANGP‐EPSC‐064 Monkton 31 2012‐PW‐77/RS‐17 1.25* a 5.1 Class II 955 605 boulders in clay > 60 Potential
76 21 ANGP‐EPSC‐063 Monkton 31 2012‐PW‐76/RS‐16 0.55* a 5.1 Class II 773 512 boulders in clay > 60 Potential
77 21 ANGP‐EPSC‐062 Monkton 31 2012‐PW‐75 0.3 a 5.1 Class II 294 759 boulders in clay > 60 Potential
78 through 81 21 ANGP‐EPSC‐090 Monkton 31 2013‐CM‐3 2.04* a 5.1, 5.2, 5.4 Class II 2326 3164 boulders in clay > 60 Potential
82, 83, 84 22 ANGP‐EPSC‐086 Monkton 31 2013‐AW‐CM‐7 5.99* a 5.1, 5.2, 5.4 Class II 315 368 boulders in clay > 60 Potential
83 through 86 22 ANGP‐EPSC‐027 Monkton 31 2012/2013‐PW‐71/72/73 3.49* a 5.1 Class II 0 652 boulders in clay > 60 Potential
87 22 ANGP‐EPSC‐070 Monkton 31 2012‐RS‐15 0.09* a 5.1, 5.2 Class II 0 426 boulders in clay > 60 Potential
87, 88 22 ANGP‐EPSC‐061 Monkton 31 2012‐PW‐70/RS‐14 0.13* a 5.1 Class II 144 562 boulders in clay > 60 Potential
88 22 ANGP‐EPSC‐060 Monkton 31 2012‐PW‐69 0.27* a 5.1 Class II 200 891 boulders in clay > 60 Potential
boulders in clay0.95* a 5.1, 5.2
5.1, 5.2, 5.4, 5.10 Class II
68 19 ANGP‐EPSC‐047 Hinesburg 28 2012‐CM‐87
18.53* a,c
Class II
59 through 65 18 ANGP‐EPSC‐087 Hinesburg 27 2013‐AW‐CM‐8
bedrock exposure
55 through 58 17 ANGP‐EPSC‐052 Hinesburg 26 2012‐JB‐31
1.47* a
5.1, 5.2, 5.4, 5.5, 5.6, 5.10
Class II boulders in clay6.59* a,c, d
Proposed Class II Wetland Buffer Trench Impacts5
(Sq Ft)
Surficial Geology Lithology Name
Shallow Depth to Bedrock(inches)
Likelyhood of Blasting
45 14 ANGP‐EPSC‐022 Williston 22 2012/2013‐CM‐219
Delineated Area(acres)
VWR Section 4.6 Presumption(s)2
VWR Section 5 Function(s)3
VHB Proposed VWR Classification4
Proposed Class II Wetland Trench
Impacts5
(Sq Ft)
VHB Impact Exhibit #
VHB Natural Resource Map Series Sheet #
CHA Plan Sheet # 1 TownWetland
Complex IDWetland ID
5.1 Class II
\\VTNFDATA\projects\57563.00 VGS Addison Expansion\ssheets\ImpactCalcs\VWR_ClassII\071813_Wildlife Working\Impacts_Master_Trench,090913_format (.5 removed),9/12/2013 1 of 2
3
Vermont Gas ‐ Addison Natural Gas Project ‐ Phase IChittenden and Addison Counties, VermontPotential Shallow Bedrock Sites Within Class II Wetlands and BuffersPrepared by VHBSeptember 12, 2013
Proposed Class II Wetland Buffer Trench Impacts5
(Sq Ft)
Surficial Geology Lithology Name
Shallow Depth to Bedrock(inches)
Likelyhood of Blasting
Delineated Area(acres)
VWR Section 4.6 Presumption(s)2
VWR Section 5 Function(s)3
VHB Proposed VWR Classification4
Proposed Class II Wetland Trench
Impacts5
(Sq Ft)
VHB Impact Exhibit #
VHB Natural Resource Map Series Sheet #
CHA Plan Sheet # 1 TownWetland
Complex IDWetland ID
91 through 94 24 ANGP‐EPSC‐026 Monkton 32 2012/2013‐PW‐67 123.39* a,b, g5.1, 5.2, 5.4, 5.5, 5.6,
5.9, 5.10 Class II 584 662 boulders in clay > 60 Potential
95, 96 25 ANGP‐EPSC‐059 Monkton 33 2012‐PW‐64 1.76* a 5.1, 5.2 Class II 1431 820 boulders in clay > 60 Potential
0 89 bedrock exposure > 60 Likely
267 816 boulders in clay > 60 Potential
98 26 ANGP‐EPSC‐076 Monkton 34 2012‐RS‐32 0.05* a 5.1 Class II 60 500 boulders in clay > 60 Potential
98 26 ANGP‐EPSC‐077 Monkton 34 2012‐RS‐33 0.26* a 5.1 Class II 233 618 boulders in clay > 60 Potential
99 through 102 26 ANGP‐EPSC‐075 Monkton 35 2012‐RS‐31 4.33* a 5.1, 5.4 Class II 0 1222 boulders in clay > 60 Potential
0 951 bedrock exposure > 60 Likely
0 1051 boulders in clay > 60 Potential
121, 122 28 ANGP‐EPSC‐072 New Haven 36 2012‐RS‐24 1.37* a 5.1, 5.2, 5.4 Class II 0 760 boulders in clay > 60 Potential
130 through 142 31 ANGP‐EPSC‐035 New Haven 40 2012‐CM‐160/161 39* a, g 5.1, 5.2, 5.4, 5.6 Class II 16453 2769 boulders in clay > 60 Potential
143, 144 32 ANGP‐EPSC‐034 New Haven 40 2012‐CM‐158 0.82* a 5.1, 5.2 Class II 738 1812 boulders in clay > 60 Potential
145 32 ANGP‐EPSC‐033 New Haven 40 2012‐CM‐157 0.14* a 5.2 Class II 0 587 boulders in clay > 60 Potential
146, 147 33 ANGP‐EPSC‐032 New Haven 40 2012‐CM‐156 3.21* a 5.1, 5.2 Class II 364 1121 boulders in clay > 60 Potential
148 34 ANGP‐EPSC‐031 New Haven 41 2012‐CM‐150 0.77* a 5.1 Class II 334 354 boulders in clay > 60 Potential
152 35 ANGP‐EPSC‐058 Middlebury 48 2012‐PW‐5 0.09* a 5.1, 5.2 Class II 0 373 boulders in clay > 60 Potential
153, 154 35 ANGP‐EPSC‐057 Middlebury 49 2012‐PW‐2 0.34* a 5.1 Class II 0 2637 boulders in clay > 60 Potential
155, 156 51 ANGP‐EPSC‐056 Middlebury 50 2012‐PW‐1/JB‐39 0.18* a 5.1, 5.2 Class II 0 2722 boulders in clay > 60 Potential
158, 159 40 ANGP‐EPSC‐078 Ferrisburgh 43 2012‐RS‐42 0.47* a 5.1 Class II 54 3083 boulders in clay > 60 Potential
160 41 ANGP‐EPSC‐080 Ferrisburgh 44 2012‐RS‐47 0.04* a 5.1 Class II 0 119 boulders in clay > 60 Potential
1 1402 > 60 Potential
0 536 > 60 Potential
162, 163 41 ANGP‐EPSC‐083 Ferrisburgh 45 2012‐RS‐52 0.36* a 5.1, 5.2 Class II 581 1707 boulders in clay > 60 Potential
162, 163 41 ANGP‐EPSC‐084 Ferrisburgh 45 2012‐RS‐53 0.08* a 5.1, 5.2 Class II 0 319 boulders in clay > 60 Potential
164 41 ANGP‐EPSC‐037 New Haven 46 2012‐CM‐176 0.27* a 5.1, 5.2 Class II 13 1547 boulders in clay > 60 Potential2,532 5,09138,575 47,474
Note: Typical depth of trench is five feet (60").*Indicates wetland continues outside of the VHB investigation area.1CHA Plan Sheet # references the June 28, 2013 Site Plans.2Alpha‐numeric codes correspond with Section 4.6 Presumptions of Significance in the 2010 Vermont Wetland Rules.
Likely = shallow depth to bedrock less than 60 inches or 'bedrock exposure' surficial geology type. Potential = shallow depth to bedrock greater than 60 inches or surficial geology type other than 'bedrock exposure'.
3VWR Section 5 Functional Criteria for Evaluating a Wetland's Significance: 5.1=Water Storage for Flood Water and Storm Runoff, 5.2=Surface and Groundwater Protection, 5.3=Fish Habitat, 5.4=Wildlife Habitat, 5.5=Exemplary Wetland Natural Community, 5.6=Rare, Threatened or Endangered Species Habitat, 5.7=Education and Research in Natural Sciences, 5.8=Recreational Value and Economic Benefits, 5.9=Open Space and Aesthetics, 5.10=Erosion Control Through Binding and Stabilizing the Soil. Functions presented are for the subject wetlands.4VHB's proposed wetland classification has been field reviewed (representative areas) by VT DEC wetlands staff.5Impacts from 5' wide trench for proposed transmission and distribution mainline. Impacts were removed where wetland and buffer impacts were less than 50 square feet (equivalent to 10 feet of linear trench). GIS impact analysis conducted using limits of disturbance created from the CHA CAD‐based design drawing: June 28, 2013.6Potential for Trench Encountering Bedrock determined from combination of Surficial Geology (by VT ANR 2008 from USGS quadrangle map sheets) and Shallow Depth to Bedrock (by NRCS 2011).
a 5.1, 5.2 Class II boulders in clay
Likely (Subtotal) (Sq Ft)Potential (Subtotal) (Sq Ft)
0.37*160, 161 41 ANGP‐EPSC‐081 Ferrisburgh 44 2012‐RS‐48
0.43* a 5.1 Class II
Class II
103, 104 27 ANGP‐EPSC‐073 Monkton 35 2012‐RS‐30
0.17* a, c 5.1, 5.4, 5.10 97 25 ANGP‐EPSC‐050 Monkton 33 2012‐JB‐12
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