Mill River Levee System_Geotechnical Data Memo_Comment Log - 12-22-20 - GZA Responses
City of Northampton DPW
Mill River Levee Geotechnical Memo
REVIEW COMMENT FORM
Reviewed by:David Veleta, P.E. and Kris Baker, P.E.
Project: Northampton Levee DPP
Comment Date: 11/17/2020 GZA Response Date: 12/22/2020
Comment
No.
Chapter Section
Figure,
Para. #,
Page No.
Comment
GZA Responses
1
Introduction
Page 1, paragraph 1
KB: See comments for the CT River system
Noted, universal comments from CT River Memo addressed in Mill River Memo.
2
Introduction
Page 1, paragraph 1
DV: Replace “will be” with “is”
Edit completed
3
Introduction
Page 1, paragraph 1
DV: Maximum height of levee of approximately 35-feet seems high. Is it measured from mean water level, so water level+bank+21’ floodwall = 35?
Based on record drawings and cross section from USACE, as well as existing as-built information, this has been changed to a max height of 25 feet. The max height section is where the
original Mill River location was filled.
4
Background
Page 2, paragraph 1
DV: Capitalize “Floodwall”
Edit completed
5
Background
Page 2 paragraph 1
DV: Add a comma after “The Floodwall”
Edit completed
6
Background
Page 2 paragraph 1
DV: Add a comma after “construction”
Edit completed
7
Background
Page 2 paragraph 3
DV: Add “and” after “El 112”
Edit completed
8
Scope of Work
Page 2, Item 3
DV: Plans indicate Figure 2 as Figure 1
Changed the exploration location plan to “Figure 2”
9
Scope of Work
Page 2, Item 4
DV: Change “Performed” to “Perform” and remove capitalization of “Testing”
Edit completed
10
2019-2020 GZA Test Borings
Page 3
KB: Add a few transitional sentences to describe the information you are required to obtain for the FEMA study to update or fill information gaps in the subsurface from the original
construction records.
Agreed. Refer to the additional sentences added on page 1 and on page 3, under “GZA 2020 Test Borings”.
10
Soil and Rock
Page 4 paragraph 4
DV: Add “Alternated”
Edit completed
11
Soil and Rock
Page 6, paragraph 3
DV: 1/16-inch to ¼-inch thick lenses of Clayey Silt or fine to medium Sand in varved clay seem pretty thin. Were these actually distinguishable?
Yes, the lenses can be measured with a tape or can be visibly seen by naked eye, as the lenses create a clear separation of material.
12
Groundwater
Page 6, paragraph 5
DV: Groundwater observations seem very sketchy since most all are above the surrounding ground surface at the adjacent toe of the slope. Consider a stronger caveat that these are not
reliable and won’t be used for seepage and stability analysis. Are groundwater elevations needed for analysis? If so, do we need monitoring wells at the toe of slope in select locations?
You are correct. We enhanced the language regarding the purpose of the water level readings reported on the logs. We have the existing well water level and will be make conservative
assumptions for the groundwater level on the land side toe. So, we do not feel as though we need to install monitoring wells at this time.
13
Email
N/A
DV: I'm not sure why these need to be separate memos, and I think it may make sense to combine them into one document. As it is, there is a lot of redundancy with 80 pages of the Drilling
Work Plan repeated in both memos.
As discussed via email on 11/17/20, the memos were kept separate as FEMA will likely want the certification process to be completed separately for the Mill River System and the Connecticut
River System. However, to reduce redundancy, we have removed the Drilling Work Plan from the memo appendices and have instead provided a reference to the Work Plan in the memo text.
14
Email
N/A
DV: There is a lot of inconsistency in page sizes at various points in both memos. Unless there is a compelling reason for other sizes I think limiting it to 8.5x11 and 11x17 makes sense.
I don't see that the 24x36 drawings provide so much detailed information that they need to be reproduced a that scale.
We have gone through the document and done a QA check to make sure the documents sizes, fonts, etc. are consistent and appropriate for reproducing them.