HomeMy WebLinkAboutItem U December 13, 1999
STAFF REPORT
To: Mayor and Members of the City Council
Attention: Keith R. Till, City Manager
From: Lee Whittenberg, Director of Development Services
Subject: CITY RESPONSE LETTER RE: "DRAFT -
GROUNDWATER FEASIBILITY STUDY REPORT,
INSTALLATION RESTORATION SITES 40 and 70,
NAVAL WEAPONS STATION, SEAL BEACH"
SUMMARY OF REQUEST
Authorize the Mayor to sign the draft response letter, with any additional comments determined
appropriate, and instruct staff to forward to the Environmental Quality Control Board for
information. Receive and File Staff Report.
DISCUSSION
The Department of the Navy is requesting comments on the "Draft Groundwater Feasibility Study
Report, Installation Restoration Sites 40 and 70, Naval Weapons Station, Seal Beach" by
December 29, 1999.
Recommendation of Environmental Quality Control Board:
The Environmental Quality Control Board (EQCB) considered this matter on December 1, 1999,
authorized the Chairperson to sign the response letter and instructed staff to forward this matter to
the City Council for final consideration and signature by the Mayor of the comment letter, as
revised. The EQCB made no changes in the comment letter.
AGENDA ITEM
C:\My DocumentsWAVWPSTA\Draft Groundwater FS, IR Sites 40&70.CC.doc\LW\12-02-99
City Response Letter re:Draft Groundwater Feasibility Study Report,
IR Sites 40 and 70, Naval Weapons Station, Seal Beach
City Council Board Staff Report
December 13, 999
water for any of the beneficial uses designated in the Basin Plan (RWQCB 1995).
Accordingly, the impacted groundwater does not pose an immediate threat to human health or
the environment.'
Summary Results for IR Sites 40 and 70
JR Site 40:
•
Groundwater contamination at IR Site 40 is characterized by relatively low levels of dissolved
VOCs affecting a relatively small area compared to IR Site 70 and other IR Program Sites.
The total mass of dissolved contamination at IR Site 40 is approximately 6 pounds.
Groundwater modeling has shown that the plume is relatively slow-moving, and it is expected
to attenuate naturally over time. Currently, no human or ecological receptors are exposed to
VOC-affected groundwater; at this time, there are no complete exposure pathways for
contaminants. Shallow groundwater underlying IR Site 40 does not presently serve as a water
source for any of the beneficial uses designated in the Basin Plan (RWQCB 1995).
Provided as Attachment 3 are the following Figures, which were provided to the EQCB,
related to IR Site 40 Physical Conceptual Model and contamination concentration levels, for
the information of the City Council:
❑ Figure 1-11, IR Site 40 - Site Physical Conceptual Model
o Figure 1-12, PCE Concentrations in Groundwater, Samples < 20' - IR Site 40
o Figure 1-13, PCE Concentrations in Groundwater, Samples 20' 45' - IR Site 40
o Figure 1-14, PCE Concentrations in Groundwater, Samples > 45' - IR Site 40
o Figure E1-4A, B, IR Site 40 - PCE Plume Interpretation - Low-Angle View to
Northwest - 50 and 100 ug/L IsoOSurface (Appendix E, Groundwater Modeling)
Five alternatives, listed below, were developed for IR Site 40, incorporating several described
technologies. The estimated present net worth for each alternative is provided in parentheses.
In addition, a summary of the time and cost-effectiveness is provided.
o Alternative 1, No Action. No further action of any type, evaluated in accordance with
the National Oil and Hazardous Substances Pollution Contingency Plan (NCP) ($0).
Medium cost-effectiveness. Low cost, but effectiveness not assessed. Estimated 35-40
years to achieve remedial action objectives (RAO).
"Draft Groundwater Feasibility Study Report, Installation Restoration Program Sites 40 and 70, Naval Weapons
Station, Seal Beach", prepared by Bechtel National, Inc. for Southwest Division, Naval Facilities Engineering
Command,October 1999,pages ES-1 and ES-2
3
Draft Groundwater FS,Qt Sites 40&70.CC
Qty Response Letter re:Draft Groundwater Feasibility Study Report,
/R Sites 40 and 70, Naval Weapons Station, Seal Beach
City Council Board Staff Report
December 13, 999
contaminant source area. Unless contained or otherwise treated, the suspected DNAPLs could
continue to provide a source for dissolved-phase contamination indefinitely. Currently, no
human or ecological receptors are exposed to VOC-affected groundwater; at this time, there
are no complete exposure pathways for contaminants. Shallow groundwater underlying IR Site
70 does not presently serve as a water source for any of the beneficial uses designated in the
Basin Plan (RWQCB 1995).
The groundwater plume at IR Site 70 was analyzed as two separate areas: a suspected DNAPL
area and the dissolved-phase plume. Separate remediation alternatives for the DNAPL area
and the remaining dissolved plume were developed and then combined to form sitewide
alternatives.
Provided as Attachment 4 are the following Figures provided to the EQCB, related to IR Site
70 Physical Conceptual Model and contamination concentration levels, for the information of
the City Council:
o Figure 1-15, Site Physical Conceptual Model - IR Site 70
o Figure 1-17, TCE Concentrations in Groundwater, Samples < 35' bgs - IR Site 70
o Figure 1-18, TCE Concentrations in Groundwater, Samples 35'- 50' bgs - IR Site 70
o Figure 1-19, TCE Concentrations in Groundwater, Samples 50'-75' bgs - IR Site 70
o Figure 1-20, TCE Concentrations in Groundwater, Samples 75'-110' bgs - IR Site 70
o Figure 1-21, TCE Concentrations in Groundwater, Samples 110'-150' bgs - IR Site 70
o Figure 1-22, TCE Concentrations in Groundwater, Samples 150'-172' bgs - IR Site 70
a Figure 1-23, TCE Concentrations in Groundwater, Samples > 172' bgs - IR Site 70
o Figure 2-1, Assumed Extent of DNAPL Area - IR Site 70
o Figure E2-3A, B, C, D, E - TCE Plume Interpretation (Appendix E, Groundwater
Modeling)
a Table E2-10, IR Site 70 - Simulated Time Required To Achieve TCE Concentrations
of 5 ug/L
Five alternatives, listed below, were developed for IR Site 70, incorporating several described
technologies. The estimated present net worth for each alternative is provided in parentheses.
In addition, a summary of the time and cost-effectiveness is provided.
o Alternative 1, No Action. No further action of any type, evaluated in accordance with
the NCP ($0). Medium cost-effectiveness. Low cost, but not effective. Natural
attenuation process would not be effective in the short run.
5
Draft Groundwater FS,IR Sites 40&70.CC
Ory Response Letter re:Draft Groundwater Feasibility Study Report,
IR Sites 40 and 70, Naval Weapons Station, Seal Beach
Ory Council Board Staff Report
December 13, 999
review and will be available at the City Council meeting for review also. Given some of the
issues raised in the document, staff prepared a draft comment letter for the review and approval of
the EQCB and the City Council. The draft comment letter is provided as Attachment 1.
Previous City Review
The City has commented on IR Sites 40 and 70 as indicated below:
o In June 1999, the City commented on a request by the California Department of Toxic
Substances Control regarding "Request for Identification of Applicable and Appropriate
Requirements (ARARs): Feasibility Study at IR Sites 40 and 70, Naval Weapons Station".
o In February 1999, the City commented on the "Draft Extended Removal Site Evaluation
Report, IR Sites 40 and 70, Naval Weapons Station, Seal Beach"
o In February 1997, the City commented on the "Pre-Final Extended Removal Site
Evaluation Work Plan, IR Sites 40 and 70, Naval Weapons Station, Seal Beach".
Proposed Response Letter
The Navy is requesting comments on the subject document by December 29, 1999. The EQCB
considered this matter on December 1, 1999, and the matter is now before City Council for a
final review and authorization of the Mayor to sign the comment letter.
Staff has prepared the initial draft of the response letter for consideration by the EQCB and
ultimately the City Council, indicating general concerns of the City (See Attachment 1).
FISCAL IMPACT
None. All project activities are the responsibility of the Department of the Navy, which are
anticipated to range from $1.0 to $2.1 million for Site 40 and from $5.8 to $11.8 million for Site
70.
RECOMMENDATION
Authorize the Mayor to sign the draft response letter, with any additional comments determined
appropriate, and instruct staff to forward to the Environmental Quality Control Board for
information. Receive and File Staff Report.
7
Draft Groundwater FS,IR Sites 40 St 70.CC
CTty Response Letter re:Draft Groundwater Feasibility Study Report,
IR Sites 40 and 70,Naval Weapons Station, Seal Beach
Cory Council Board Staff Report
December 13, 999
o Figure 1-13, PCE Concentrations in Groundwater, Samples 20' 45' -
IR Site 40
o Figure 1-14, PCE Concentrations in Groundwater, Samples > 45' -
IR Site 40
o Figure E1-4A, B, IR Site 40 - PCE Plume Interpretation - Low-
Angle View to Northwest - 50 and 100 ug/L IsoOSurface (Appendix
E, Groundwater Modeling)
Attachment 4: Additional IR Site 70 Figures and Tables
o Figure 1-15, Site Physical Conceptual Model - IR Site 70
o Figure 1-17, TCE Concentrations in Groundwater, Samples < 35'
bgs - IR Site 70
o Figure 1-18, TCE Concentrations in Groundwater, Samples 35'- 50'
bgs - IR Site 70
o Figure 1-19, TCE Concentrations in Groundwater, Samples 50'-75'
bgs - IR Site 70
o Figure 1-20, TCE Concentrations in Groundwater, Samples 75'-110'
bgs - IR Site 70
o Figure 1-21, TCE Concentrations in Groundwater, Samples 110'-
150' bgs - IR Site 70
o Figure 1-22, TCE Concentrations in Groundwater, Samples 150'-
172' bgs - IR Site 70
o Figure 1-23, TCE Concentrations in Groundwater, Samples > 172'
bgs - IR Site 70
o Figure 2-1, Assumed Extent of DNAPL Area - IR Site 70
o Figure E2-3A, B, C, D, E - TCE Plume Interpretation (Appendix E,
Groundwater Modeling)
o Table E2-10, IR Site 70 - Simulated Time Required To Achieve
TCE Concentrations of 5 ug/L
9
Draft Groundwater FS,IR Sites 40&70.CC
City Response Letter re:Draft Groundwater Feasibility Study Report,
IR Sites 40 and 70, Naval Weapons Station, Seal Beach
City Council Board Staff Report
December 13, 999
ATTACHMENT 1
DRAFT COMMENT LETTER FROM EQCB AND
CITY COUNCIL TO DEPARTMENT OF NAVY RE:
"DRAFT GROUNDWATER FEASIBILITY STUDY
REPORT, INSTALLATION RESTORATION
PROGRAM SITES 40 AND 70, NAVAL WEAPONS
STATION, SEAL BEACH"
Draft Groundwater FS,IR Sites 40&70.CC 10
City Response Letter re:Draft Groundwater Feasibility Study Report,
1R Sites 40 and 70, Naval Weapons Station, Seal Beach
City Council Board Staff Report
December 13, 999
December 13, 1999
Weapons Support Facility
Attn: Pei-Fen Tamashiro, Installation Restoration Coordinator
800 Seal Beach Blvd.
Seal Beach, CA 90740-5000
SUBJECT: "Draft Groundwater Feasibility Study Report, Installation
Restoration Program Sites 40 and 70, Naval Weapons Station, Seal
Beach"
Dear Ms. Tamashiro: DRAFT
The City of Seal Beach has reviewed the report from the Department of the Navy relative to
"Draft Groundwater Feasibility Study Report, Installation Restoration Program Sites 40 and
70, Naval Weapons Station, Seal Beach". It should be noted that the City has only reviewed in
detail the "Executive Summary", and Chapters 5 and 6 of the subject document. Upon a
review of those portions of the document by the Environmental Quality Control Board and the
City Council of the City of Seal Beach, the City has the following general and specific
comments.
General Comments on the Document
The Environmental Q«ality Control Board and the City Council understand this document
provides a summary of the nature and extent of certain identified chemicals of potential concern
(COPCs) identified during previous site investigations at IR Sites 40 and 70. The document
further develops and evaluates potential remedial alternatives to mitigate the identified risks to
human health at the identified sites. After receiving public and regulatory agency review
comments, the remedy selection process will proceed and a record of decision will be prepared.
11
Draft Groundwater FS,IR Sites 40&70.CC
City Response Letter re.•Draft Groundwater Feasibility Study Report,
IR Sites 40 and 70, Naval Weapons Station, Seal Beach
City Council Board Staff Report
December 13, 999
alternatives, we are appreciative of the Navy proceeding with this evaluation in an expeditious and
timely manner. The length of time to conduct this type of evaluation and reach an action
determination was a concern expressed in our letter of February 8, 1999. The timely preparation
of this document, and the future decisions to be made based on public and regulatory agency
reviews and comments, are sincerely appreciated by the City.
Preferred Remedial Alternatives for IR Sites 40 and 70
The Environmental Quality Control Board and City staff conducted an in-depth review of
Chapters 5 and 6 of the subject document in order to develop a fuller understanding of the various
remedial alternatives discussed.
As a general statement, the City would go on record as favoring those remedial alternatives that
are capable of accomplishing the established remediation goals in the shortest period of time,
taking into account reasonable expectation of being able to implement the determined action in a
cost-effective manner. The thorough discussion within Chapters 5 and 6 was helpful in gaining a
fuller understanding of the benefits and liabilities of each of the identified alternatives.
IR Site 40- Building 240
The City would recommend the Navy consider the following alternatives for IR Site 40, in the
order presented:
o Alternative 5b - Chemical Oxidation
o Alternative 5a - Lactate Enhancement
o Alternative 4 - Pump and Treat
10P6**.R
IR Site 70- RT&E Area
The City would recommend the Navy consider the following alternatives for IR Site 70, in the
order presented:
o Alternative 9 - Pump and Treat (dissolved plume) and In Situ Treatment (DNAPL area)
o Alternative 6 - Hydraulic Containment (dissolved plume) and In Situ Treatment (DNAPL
area)
The Environmental Quality Control Board of the City of Seal Beach considered and reviewed the
Draft Groundwater Feasibility Report and an accompanying Staff Report on December 1, 1999,
with the City Council considering and discussing these same documents and reports on December
13
Draft Groundwater FS,IR Sites 40&70.CC
City Response Letter re:Draft Groundwater Feasibility Study Report,
IR Sites 40 and 70,Naval Weapons Station,Seal Beach
City Council Board Staff Report
December 13, 999
ATTACHMENT 2
"DRAFT GROUNDWATER FEASIBILITY STUDY REPORT,
INSTALLATION RESTORATION PROGRAM SITES 40 AND 70,
NAVAL WEAPONS STATION, SEAL BEACH", PREPARED BY
BECHTEL NATIONAL, INC. FOR SOUTHWEST DIVISION,
NAVAL FACILITIES ENGINEERING COMMAND, DATED
OCTOBER 1999
NOTE: COMPLETE DOCUMENT HAS NOT BEEN
PROVIDED TO THE CITY COUNCIL DUE TO THE LENGTH
OF THE DOCUMENT, 877 PAGES IN 2 VOLUMES. STAFF
HAS PREVIOUSLY PROVIDED THE "EXECUTIVE
SUMMARY", "TABLE OF CONTENTS", SECTION 5 —
"DETAILED ANALYSIS OF REMEDIAL ALTERNATIVES",
AND SECTION 6 — "COMPARATIVE ANALYSIS OF
REMEDIAL ALTERNATIVES", TO THE EQCB FOR
REVIEW IN CONSIDERING THIS MATTER. THE
COMPLETE DOCUMENT IS AVAILABLE FOR REVIEW AT
THE DEPARTMENT OF DEVELOPMENT SERVICES
o FIGURE ES-2, HORIZONTAL LIMITS OF CHLORINATED-
VOC PLUME, IR SITE 40, PAGE ES-3
o FIGURE ES-3, HORIZONTAL LIMITS OF CHLORINATED-
VOC DISSOLVED PLUME AND DNAPL AREA PLUME, IR
SITE 70, PAGE ES-5
15
Draft Groundwater FS,IR Sites 40&70.CC
NOTE
FIGURES PROVIDED IN CITY
COUNCIL AND LIBRARY PACKETS
ONLY. FIGURES ARE AVAILABLE
FOR REVIEW AT CITY LIBRARIES
AND THE DEPARTMENT OF
DEVELOPMENT SERVICES
City Response Letter re:Draft Groundwater Feasibility Study Report,
IR Sites 40 and 70, Naval Weapons Station, Seal Beach
City Council Board Staff Report
December 13, 999
ATTACHMENT 3
ADDITIONAL IR SITE 40 FIGURES
o FIGURE 1-11, IR SITE 40 - SITE PHYSICAL
CONCEPTUAL MODEL
❑ FIGURE 1-12, PCE CONCENTRATIONS IN
GROUNDWATER, SAMPLES < 20' - IR SITE 40
❑ FIGURE 1-13, PCE CONCENTRATIONS IN
GROUNDWATER, SAMPLES 20' 45' - IR SITE 40
o FIGURE 1-14, PCE CONCENTRATIONS IN
GROUNDWATER, SAMPLES > 45' - IR SITE 40
o FIGURE E1-4A, B, IR SITE 40 - PCE PLUME
INTERPRETATION - LOW-ANGLE VIEW TO
NORTHWEST - 50 AND 100 UG/L ISOOSURFACE
(APPENDIX E, GROUNDWATER MODELING)
16
Draft Groundwater FS,IR Sites 40&70.CC
NOTE
FIGURES PROVIDED IN CITY
COUNCIL AND LIBRARY PACKETS
ONLY. FIGURES ARE AVAILABLE
FOR REVIEW AT CITY LIBRARIES
AND THE DEPARTMENT OF
DEVELOPMENT SERVICES
Qty Response Letter re.•Draft Groundwater Feasibility Study Report,
IR Sites 40 and 70,Naval Weapons Station, Seal Beach
Qty Council Board Staff Report
December 13, 999
ATTACHMENT 4
ADDITIONAL IR SITE 70 FIGURES AND TABLES
o FIGURE 1-15, SITE PHYSICAL CONCEPTUAL MODEL -
IR SITE 70
o FIGURE 1-17, TCE CONCENTRATIONS IN
GROUNDWATER, SAMPLES < 35' BGS - IR SITE 70
o FIGURE 1-18, TCE CONCENTRATIONS IN
GROUNDWATER, SAMPLES 35'- 50' BGS - IR SITE 70
o FIGURE 1-19, TCE CONCENTRATIONS IN
GROUNDWATER, SAMPLES 50'-75' BGS - IR SITE 70
o FIGURE 1-20, TCE CONCENTRATIONS IN
GROUNDWATER, SAMPLES 75'-110' BGS - IR SITE 70
o FIGURE 1-21, TCE CONCENTRATIONS IN
GROUNDWATER, SAMPLES 110'-150' BGS - IR SITE 70
o FIGURE 1-22, TCE CONCENTRATIONS IN
GROUNDWATER, SAMPLES 150'-172' BGS - IR SITE 70
o FIGURE 1-23, TCE CONCENTRATIONS IN
GROUNDWATER, SAMPLES > 172' BGS - IR SITE 70
o FIGURE 2-1, ASSUMED EXTENT OF DNAPL AREA - IR
SITE 70
o FIGURE E2-3A, B, C, D, E - TCE PLUME
INTERPRETATION (APPENDIX E, GROUNDWATER
MODELING)
o TABLE E2-10, IR SITE 70 - SIMULATED TIME
REQUIRED TO ACHIEVE TCE CONCENTRATIONS OF 5
UG/L
17
Draft Groundwater FS,IR Sites 40&70.CC
NOTE
FIGURES AND TABLE PROVIDED IN
CITY COUNCIL AND LIBRARY
PACKETS ONLY. FIGURES AND
TABLE ARE AVAILABLE FOR
REVIEW AT CITY LIBRARIES AND
THE DEPARTMENT OF
DEVELOPMENT SERVICES