HomeMy WebLinkAboutItem M April 12, 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: APPROVAL OF CITY RESPONSE LEITER RE:
DRAFT GROUNDWATER MONITORING STUDY at IR
STNS 1 and 7 — NAVAL WEAPONS STATION SEAL
BEACH
RECOMMENDATION
Authorize the Mayor to sign the it ft response lette..., with any additional comments determined
appropriate. Instruct staff to forward to the appropriate parties. Receive and File Staff Report.
Recommendation of Environmental Quality Control Board:
The Environmental Quality Control Board (EQCB) considered this matter on March 31, 1999, and
authorized the Chairperson to sign the proposed response letter and forward to the City Council for
review by the City Council and signature by the Mayor. The EQCB did recommend minor
amendments to the proposed response letter, and those are indicated by double strikethrough for
e-deleted and by bold and underline for language to be added.
DISCUSSION
Objectives of Groundwater Monitoring Study at IR Sites 1 & 7:
The objectives of the continuous groundwater level monitoring at Sites 1 and 7 are to:
a Evaluate whether the groundwater at Site 1 is tidally-influenced and, if so, assess the
direction of groundwater flow at Site 1 using continuous water level monitoring.
o Confirm the direction of groundwater flow at Site 7 during the wet season using continuous
water level monitoring.
AGENDA ITEM /1/
C:\My Documents\NAVWPSTA\II2 Sites 1 &7 Groundwater Monitor PIan.CC SR.doc\LW\03-31-99
Draft Groundwater Monitoring Study-IR Sites 1 & 7— Weapons Support Facility
City Council Staff Report
April 12, 1999
The objectives of the groundwater sampling are to:
o Evaluate the source of elevated levels of gross alpha in groundwater as Site 1 and the source
of gross alpha and gross beta in groundwater at Site 7 detected in the earlier Remedial
Investigation (RI) sampling effort.
o Assess the recent concentrations of metals above federal ambient water quality criteria
(AWQC) at Site 1 and the concentrations of metals and cyanide above AWQC in
groundwater at Site 7. All concentrations of metals and cyanide are also compared against
California AWQC.
Note that the AWQC are not directly applicable as groundwater cleanup criteria; they are surface
water criteria but not groundwater criteria. The AWQC were used in the RI for general
comparison purposes only.
The above groundwater monitoring program was determined appropriate at a meeting on February
10, 1998 with representatives of California Department of Toxic Substances Control, Santa Ana
Regional Water Quality Control Board, CH2M Hill, US Navy Southwest Division, and the
Weapons Support Facility.
Recommendations of Groundwater Monitoring Study:
Groundwater at Site 1 flows in the general direction of the National Wildlife Refuge (NWR).
However, there is no indication of groundwater contamination. No further groundwater monitoring
activities, either continuous water level monitoring or groundwater sampling are recommended for
characterization of groundwater.
Site 7 was used by the Station to dispose of various wastes. Operations began at the site more than
40 years ago and ceased about 25 years ago. Natural attenuation processes appear to have been
active over time. Although no well-defined plumes exist, water quality data suggest Site 7
groundwater has been impacted by prior site activities. Therefore continued groundwater sampling
at Site 7 is recommended. However, no additional continuous water level monitoring is necessary.
The following groundwater sampling program is recommended:
o Monitoring well network: All three wells located within the NWR (i.e., W41, W42 and
W43) will serve as "sentinel" wells for monitoring potential contamination from Site 7.
o Request for analysis for metals and cyanide: Several metals and cyanide have exceeded
their respective AWQC and background concentrations but the results indicate no further
need for radiological testing.
IR Sites I&7 Groundwater Monitor PIan.CC SR 2
Draft Groundwater Monitoring Study-IR Sites 1 & 7— Weapons Support Facility
City Council Staff Report
April 12, 1999
❑ Five-year monitoring period: Sample for 5 more years and revisit the groundwater
sampling program at the end of the 5-year period.
o Sampling frequency: For the first year, sample semiannually, and annually thereafter (for
4 years). Data from at least six sampling events are available and no increasing trends in
concentrations have been detected. One or more of the sampling events should be
conducted during periods of heavy rainfall when the groundwater flow direction is expected
to be towards the NWR. Testing of the water quality of the wells located in the NWR
would provide better measurements of potential impacts to the aquatic community.
Document Availability:
The subject document is available for review at the Weapons Support Facility and at the
Department of Development Services, City Hall, 211 Eighth Street.
Additional Information regarding project:
Please refer to the EQCB Staff Report of March 31, 1999 (Attachment 2) for discussion regarding
the following information that was presented to the EQCB:
a Overview of Previous City Reviews
o Overview of Proposed Project
o Site 1 Description
o Site 7 Description
•
NOTED AND APPROVED
/ .1 - /,, ,e_ .."..i :_1!?
- Whittenberg, Director Keith4. ill
Department of Development Services City Manager
ATTACHMENTS: (2)
IR Situ I &7 Groundwater Monitor Plan.CC SR 3
Draft Groundwater Monitoring Study-IR Sites 1 & 7— Weapons Support Facility
City Council StafReport
April 12, 1999
Attachment 1: Draft Comment Letter to Weapons Support Facility, Seal Beach re: "Draft
Groundwater Monitoring Study at Sites 1 & 7, Weapons Support Facility
Seal Beach", as approved by the EQCB on March 31, 1999
Attachment 2: Environmental Quality Control Board Staff Report, dated March 31, 1999,
with complete Attachments, including: "Draft Groundwater Monitoring
Study at Sites 1 & 7, Weapons Support Facility Seal Beach" prepared by
Navy Facilities Engineering Command, Southwest Division, dated 18
February, 1998
Note: Complete document not provided due to length, 99 pages. Provided
are Title Page, Contents, Executive Summary, Figures 1-2, 1-3 and 1-4,
and Conclusions and Recommendations
•
rR Site.1 &7 Groundwater Monitor Ptan.CC SR 4
Draft Groundwater Monitoring Study-IR Sites 1 & 7— Weapons Support Facility
City Council StafReport
April 12, 1999
ATTACHMENT 1
Draft Comment Letter to Weapons Support
Facility, Seal Beach re: "Draft Groundwater
Monitoring Study at Sites 1 & 7, Weapons
Support Facility Seal Beach", as approved by the
EQCB on March 31, 1999
IR Sites 1 &7 Groundwater Monitor P1an.CC SR 5
Draft Groundwater Monitoring Study-IR Sites 1 & 7— Weapons Support Facility
City Council Staff Report
April 12, 1999
April 12, 1999
Department of Navy
Weapons Support Facility, Seal Beach
Attn: Robert Robinson, Installation Restoration Coordinator
800 Seal Beach Boulevard
Seal Beach, CA 90740-5000
Dear Mr. Robinson:
SUBJECT: CITY OF SEAL BEACH COMMENTS RE: "Draft Groundwater
Monitoring Study at Sites 1 & 7, Weapons Support Facility Seal
Beach"
The City of Seal Beach has reviewed the above referenced documents and concurs with the
recommendations and findings of the groundwater monitoring study. The groundwater monitoring
study has adequately described potential pathways to the groundwater and Any potential chemicals
of concern at IR Sites 1 and 7. The City is particularly appreciative of the recommendations
relative to the 5-year groundwater sampling program at IR Site 7, the Station Landfill. The
determination of impacts to the National Wildlife Refuge from past disposal practices at the Station
Landfill are clearly and decisively dependent on the result of the results of this long-term sampling
study.
The City notes and appreciates the cooperation between Among the Navy, and the California
Department of Toxic Substances Control and the Santa Ana Regional Water Quality Control Board
in the development and implementation of this groundwater monitoring study. The involvement of
these agencies is important to ensuring that all relevant concerns of the regulatory agencies are
addressed in these this documents. Please provide the City with a copy of the final report
regarding the results of these-stediee this study at the appropriate time.
It would be helpful to include within the "Executive Summary" the detailed groundwater sampling
program for IR Site 7 that is set forth on page 6-3. This would allow the casual reader to fully
IR Sites 1&7 Groundwater Monitor PIan.CC SR 6
Draft Groundwater Monitoring Study-1R Sites 1 & 7— Weapons Support Facility
City Council Staff Report
April 12, 1999
understand the long-term sampling program described in the Executive Summary without having to
read through the entire document to find the detailed recommendations regarding that sampling
program. In addition, the document itself is dated 18 February 1998, and that date should be
verified, as it would seem a 1999 date is the most appropriate.
Thank you for allowing us to comment on the draft "Groundwater Monitoring Study at IR Sites 1
and 7". If you have any questions or require further information, please contact Mr. Lee
Whittenberg, Director of Development Services Department, (562) 431-2527 at your earliest
convenience. He will be able to respond to any additional questions which you may have regarding
this matter.
Sincerely,
Paul Yost Donna McGuire, Chairperson
Mayor Environmental Quality Control Board
cc: City Council
Environmental Quality Control Board
Archaeological Advisory Committee
City Manager
Director of Development Services
IR Sites I &7 Groundwater Monitor PIan.CC SR 7
Draft Groundwater Monitoring Study-IR Sites 1 & 7— Weapons Support Facility
City Council Staff Report
April 12, 1999
ATTACHMENT 2
Environmental Quality Control Board Staff
Report, dated March 31, 1999, with complete
Attachments, including: "Draft Groundwater
Monitoring Study at Sites 1 & 7, Weapons
Support Facility Seal Beach" prepared by Navy
Facilities Engineering Command, Southwest
Division, dated 18 February, 1998
Note: Complete document not provided due to length, 99
pages. Provided are Title Page, Contents, Executive
Summary, Figures 1-2, 1-3 and 1-4, and Conclusions and
Recommendations
IR Sites 1 &7 Groundwater Monitor Plan.CC SR 8
March 31, 1999
STAFF REPORT
To: Chairman and Members of the Environmental Quality Control Board
From: Lee Whittenberg, Director of Development Services
Subject: CITY RESPONSE LETTER RE: DRAFT
GROUNDWATER MONITORING STUDY at IR SITES 1
and 7 -NAVAL WEAPONS STATION SEAL BEACH
RECOMMENDATION
Authorize the Chairman to sign the draft response letter, with any additional comments determined
appropriate. Instruct staff to forward to the City Council for final review and authorization for the
Mayor to sign. Receive and File Staff Report.
DISCUSSION
overview Qf Previous au Reviews:
In March 1995 the City Council, Planning Commission, Environmental Quality Control Board and
Archaeological Advisory Committee were provided a summary report regarding "Draft Final
Remedial Investigation Report: Sites 1, 7, 19, and 22". The City did not comment on this
document due to a short response period and because the report was being reviewed by the
California Environmental Protection Agency, California Department of Fish and Game, California
Department of Toxic Substances Control, U.S. Environmental Protection Agency, U.S. Fish and
Wildlife Service, California Regional Water Quality Control Board, State Water Resources Control
Board, and the Restoration Advisory Board.
In May 1996 the Archaeological Advisory Committee provided a comment letter on the "Final
Remedial Investigation Report for Operable Units 1, 2, and 3 (Site 1), Seal Beach Naval Weapons
Station". On October 1, 1996, the City Council provided a comment letter to the California
Department of Toxic Substances Control regarding "Request for Applicable or Relevant and
Appropriate Requirements (ARARs) of Site 1, Naval Weapons Station Seal Beach". With the
Archaeological Advisory Committee and EQCB provided copies of that letter on October 9 and
October 8, 1996, respectively.
In addition, the Archaeological Advisory Committee has previously provided comments to the
Department of Navy regarding "Draft Engineering Evaluation/Cost Analysis - Operable Unit 1,
C:1My Documents\NAVWPSTAVR Sites 1 &7 Groundwater Monitor P1an.EQCB 2.doc\LW\03-04-99
Draft Groundwater Monitoring Study-IR Sites 1 & 7— Weapons Support Facility
Environmental Quality Control Board Staff Report
March 31, 1999
Site 1, - Wastewater Sealing Pond", Identification of Location Specific 'Applicable or Relevant
and Appropriate Requirements (ARARs)" in a letter dated January 16, 1997. Further, the
Archaeological Advisory Committee provided comments on November 12, 1997 regarding
*Cultural Resources Inventory for Site 1, Former Wastewater Settling Pond".
On January 21, 1997, the EQCB authorized the Chairman to sign a letter to the Department of
Toxic Substances Control regarding a "Request for Identification of Applicable and Appropriate
Requirements (ARARs)fora Non-lime Critical Removal Action at Sites 7, 8, and 19".
On March 25, 1998 the EQCB reviewed and approved a response letter to the Navy regarding the
"Draft Field Sampling Plan for the Groundwater Monitoring Study at Sites 1 & 7, Weapons
Support Facility Seal Beach" prepared by Navy Facilities Engineering Command, Southwest
Division, dated 11 March, 1998; and the "Draft Quality Assurance Project Plan for the
Groundwater Monitoring Study at Sites 1 & 7, Weapons Support Facility Seal Beach" prepared by
Navy Facilities Engineering Command, Southwest Division, dated 11 March, 1998.
Overview of Proposed Project:
The Department of the Navy (DON) has circulated "Draft Groundwater Monitoring Study at Sites
1 and 7, Naval Weapons Station Seal Beach" and is requesting comments by April 17, 1999. Staff
has prepared a 'Draft Comment Letter" for consideration by the EQCB, provided as Attachment 1.
Due to the comment period time constraint of April 17, 1999, the City Council will be provided to
the City Council on April 12, 1999. The complete document has not been provided to the EQCB.
Site I Description
Site 1 is a triangular-shaped depression bordered on the east by railroad tracks, on the west by 6th
Street, and on the south by Case Road and railroad tracks. Wastewater from Building 71 was
discharged to the depression, forming a pond. Although Site 1 is designated the "Wastewater
Settling Pond", it no longer contains surface water or sediments. Native vegetation currently grows
in the former pond area and is controlled by base personnel. Site 1 also consists of an area of
contaminated soil outside the wastewater settling pond where wastewater seeped through the ballast
under the railroad tracks. A fuller description of the types of waste disposal activities that occurred
at Site 1 is found on page 1-4 of the subject report. Refer to Figure 1-2 and 1-3 of the subject report
for Site 1 location maps (provided within Attachment 2).
Site 7 Description
Site 7, the Station landfill, is located at the southern boundary of the Weapons Station along
Perimeter Road. This site is bounded on the north by a railroad spur and oval laydown area, and
on the south by a drainage ditch and Perimeter Road. The eastern boundary was determined using
1R sites 1 &7 Groundwater Monitor Plan.EQCB 2 2
Draft Groundwater Monitoring Study-IR Sites 1 & 7— Weapons Support Facility
Environmental Quality Control Board Staff Report
March 31, 1999
aerial photographs (by previous investigators). The western boundary extends to Perimeter Road
in the tidal saltmarsh at the southeastern corner of the Nation Wildlife Refuge. Refer to Figure 1-2
and 1-4 of the subject report for Site 7 location maps (provided within Attachment 2).
Objectives of Groundwater Monitoring Study at IR Sites 1 & 7:
The objectives of the continuous groundwater level monitoring at Sites 1 and 7 are to:
o Evaluate whether the groundwater at Site 1 is tidally-influenced and, if so, assess the
direction of groundwater flow at Site 1 using continuous water level monitoring.
o Confirm the direction of groundwater flow at Site 7 during the wet season using continuous
water level monitoring.
The objectives of the groundwater sampling are to:
o Evaluate the source of elevated levels of gross alpha in groundwater as Site 1 and the source
of gross alpha and gross beta in groundwater at Site 7 detected in the earlier Remedial
Investigation (RI) sampling effort.
o Assess the recent concentrations of metals above federal ambient water quality criteria
(AWQC) at Site 1 and the concentrations of metals and cyanide above AWQC in
groundwater at Site 7. All concentrations of metals and cyanide are also compared against
California AWQC.
Note that the AWQC are not directly applicable as groundwater cleanup criteria; they are surface
water criteria but not groundwater criteria. The AWQC were used in the RI for general
comparison purposes only.
The above groundwater monitoring program was determined appropriate at a meeting on February
10, 1998 with representatives of California Department of Toxic Substances Control, Santa Ana
Regional Water Quality Control Board, CH2M Hill, US Navy Southwest Division, and the
Weapons Support Facility.
Recommendations of Groundwater Monitoring Study:
Groundwater at Site 1 flows in the general direction of the National Wildlife Refuge (NWR).
However, there is no indication of groundwater contamination. No further groundwater monitoring
activities, either continuous water level monitoring or groundwater sampling are recommended for
characterization of groundwater.
Site 7 was used by the Station to dispose of various wastes. Operations began at the site more than
40 years ago and ceased about 25 years ago. Natural attenuation processes appear to have been
IR Sites 1 &7 Groundwater Monitor PI n.EQCB 2 3
Draft Groundwater Monitoring Study-IR Sites 1 & 7- Weapons Support Facility
Environmental Quality Control Board Staff Report
March 31, 1999
active over time. Although no well-defined plumes exist, water quality data suggest Site 7
groundwater has been impacted by prior site activities. Therefore continued groundwater sampling
at Site 7 is recommended. However, no additional continuous water level monitoring is necessary.
The following groundwater sampling program is recommended:
o Monitoring well network: All three wells located within the NWR (i.e., W41, W42 and
W43) will serve as "sentinel" wells for monitoring potential contamination from Site 7.
o Request for analysis for metals and cyanide: Several metals and cyanide have exceeded
their respective AWQC and background concentrations but the results indicate no further
need for radiological testing.
o Five-year monitoring period: Sample for 5 more years and revisit the groundwater
sampling program at the end of the 5-year period.
o Sampling frequency: For the first year, sample semiannually, and annually thereafter (for
4 years). Data from at least six sampling events are available and no increasing trends in
concentrations have been detected. One or more of the sampling events should be
conducted during periods of heavy rainfall when the groundwater flow direction is expected
to be towards the NWR. Testing of the water quality of the wells located in the NWR
would provide better measurements of potential impacts to the aquatic community. ,
Document Availability:
The subject document is available for review at the Weapons Support Facility and at the
Department of Development Services, City Hall, 211 Eighth Street.
RECOMMENDATION:
Authorize the Chairman to sign the draft response letter, with any additional comments determined
appropriate. Instruct staff to forward to the City Council for final review and authorization for the
Mayor to sign. Receive and File Staff Report.
Ae-
t,)% 42�
'ttenberg,'Director
Department of Development Servi
ATTACHMENTS: (2)
IR Sites I &7 Groundwater Monitor Plan.EQCB 2 4
Draft Groundwater Monitoring Study-IR Sites 1 & 7— Weapons Support Facility
Environmental Quality Control Board Staff Report
March 31, 1999
Attachment 1: Draft Comment Letter to Weapons Support Facility, Seal Beach re: "Draft
Groundwater Monitoring Study at Sites 1 & 7, Weapons Support Facility
Seal Beach"
Attachment 2: "Draft Groundwater Monitoring Study at Sites 1 & 7, Weapons Support
Facility Seal Beach" prepared by Navy Facilities Engineering Command,
Southwest Division, dated 18 February, 1998
Note: Complete document not provided due to length, 99 pages. Provided
are Title Page, Contents, Executive Summary, Figures 1-2, 1-3 and 1-4,
and Conclusions and Recommendations
IR Sites 1 &7 Groundwater Monitor Ptan.EQCB 2 5
Draft Groundwater Monitoring Study-IR Sites 1 & 7— Weapons Support Facility
Environmental Quality Control Board Staff Report
March 31, 1999
ATTACHMENT 1
Draft Comment Letter to Weapons Support
Facility, Seal Beach re: "Draft Groundwater
Monitoring Study at Sites 1 & 7, Weapons
Support Facility Seal Beach"
IR Sites 1 &7 Groundwater Monitor Plan.EQCB 2 6
Draft Groundwater Monitoring Study-IR Sites 1 & 7— Weapons Support Facility
Environmental Quality Control Board Staff Report
March 31, 1999
April 12, 1999
Department of Navy
Weapons Support Facility, Seal Beach
Attn: Robert Robinson, Installation Restoration Coordinator
800 Seal Beach Boulevard
Seal Beach, CA 90740-5000
Dear Mr. Robinson: ORP
SUBJECT: CITY OF SEAL BEACH COMMENTS RE: "Draft Groundwater
Monitoring Study at Sites 1 & 7, Weapons Support Facility Seal
Beach"
The City of Seal Beach has reviewed the above referenced documents and concurs with the
recommendations and findings of the groundwater monitoring study. The groundwater monitoring
study has adequately described potential pathways to the groundwater and potential chemicals of
concern at IR Sites 1 and 7. The City is particularly appreciative of the recommendations relative
to the 5-year groundwater sampling program at IR Site 7, the Station Landfill. The determination
of impacts to the National Wildlife Refuge from past disposal practices at the Station Landfill are
clearly and decisively dependent on the result of the results of this long-term sampling study.
The City notes and appreciates the cooperation between the Navy and the California Department of
Toxic Substances Control and the Santa Ana Regional Water Quality Control Board in the
development and implementation of this groundwater monitoring study. The involvement of these
agencies is important to ensuring that all relevant concerns of the regulatory agencies are addressed
in these documents. Please provide the City with a copy of the final report regarding the results of
these studies at the appropriate time.
It would be helpful to include within the "Executive Summary" the detailed groundwater sampling
program for IR Site 7 that is set forth on page 6-3. This would allow the casual reader to fully
understand the long-term sampling program described in the Executive Summary without having to
IR Sites 1 &7 Groundwater Monitor P1an.EQCB 2 7
Draft Groundwater Monitoring Study-IR Sites 1 & 7— Weapons Support Facility
Environmental Quality Control Board Staff Report
March 31, 1999
read through the entire document to find the detailed recommendations regarding that sampling
program. In addition, the document itself is dated 18 February 1998, and that date should be
verified, as it would seem a 1999 date is the most appropriate.
Thank you for allowing us to comment on the draft "Groundwater Monitoring Study at IR Sites 1
and 7". If you have any questions or require further information, please contact Mr. Lee
Whittenberg, Director of Development Services Department, (562) 431-2527 at your earliest
convenience. He will be able to respond to any additional questions which you may have regarding
this matter.
Sincerely,
RP
Paul Yost Donna McGuire, Chairperson
Mayor Environmental Quality Control Board
cc: City Council
Environmental Quality Control Board
Archaeological Advisory Committee
City Manager
Director of Development Services
IR Situ 1&7 Groundwater Monitor P1an.EQCB 2 8
Draft Groundwater Monitoring Study-IR Sites 1 & 7— Weapons Support Facility
Environmental Quality Control Board Staff Report
March 31, 1999
ATTACHMENT 2
"Draft Groundwater Monitoring Study at Sites 1
& 7, Weapons Support Facility Seal Beach"
prepared by Navy Facilities Engineering
Command, Southwest Division, dated 18
February, 1998
Note: Complete document not provided due to length, 99
pages. Provided are Title Page, Contents, Executive
Summary, Figures 1-2, 1-3 and 1-4, and Conclusions and
Recommendations
IR Sites I &7 Groundwater Monitor Plan.EQCB 2 9
DRAFT
Groundwater Monitoring Study
at Sites 1 and 7
Naval Weapons Station Seal Beach
Prepared by
Naval Facilities Engineering Command,
Southwest Division
Prepared in partnership with
111110 CH2MHILL
3 Hutton Centre Drive
Suite 200
Santa Ana, California 92707
Under
SWDIV Contract N68711-96-D-2299Delivery Order#5
Project Number 144278.05.RT
18 FEBRUARY 1998
SCO/983480016.D0C/97
Contents
Section Page
Executive Summary .»»...».».....»..». ».. ES-1
Objectives ES-1
Continuous Water Level Monitoring ES-1
Groundwater Sampling ES-2
Recommendations ES-3
1.0 Introduction ». ......»..»...» .... 1-1
1.1 Purpose 1-1
1.1.1 Summary of Remedial Investigation 1-1
1.1.2 Objectives 1-2
1.2 Site Description and History 1-2
1.2.1 Location 1-2
1.2.2 Operations 1-3
1.2.3 WPNSTA Seal Beach History 1-3
1.2.4 National Wildlife Refuge 1-3
1.2.5 Site 1 Description 1-4
1.2.6 Site 7 Description 1-5
2.0 Environmental Setting 2-1
2.1 Climate 2-1
2.1.1 Wind Conditions 2-i
2.1.2 Precipitation 2-1
2.2 Geology and Hydrogeology 2-2
2.2.1 Regional Geology and Hydrogeology 2-2
2.2.2 Site Geology and Hydrogeology 2-5
2.3 Hydrology 2-6
2.3.1 Regional Hydrology 2-6
2.3.2 Site Hydrology 2-7
3.0 Methods and Procedures ...».. 3-1
3.1 Well Surveying 3-1
3.2 Water Level Monitoring 3-1
3.2.1 Field Procedures 3-2
3.2.2 Data Interpretation Method 3-3
3.3 Groundwater Sampling 3-6
3.3.1 Field Procedures 3-6
3.3.2 Management of Investigation-Derived Waste 3-9
3.3.3 Laboratory Analysis 3-9
3.3.4 Data Interpretation Methods 3-10
4.0 Results of 1998 Monitoring Events 4-1
4.1 Water Level Monitoring 4-1
scOI98348OO17.DOC 97
CONTENTS.CONTINUES
Section Page
4.1.1 Dock 41
= 4.1.2 Site 1: Wastewater Settling Pond 4-1
4.1.3 Site 7-Station Landfill 42
4.2 Groundwater Sampling 43
4.2.1 Site 1:Wastewater Settling Pond 4-4
• 4.2.2 Site 7: Station Landfill 4-4
4.2.3 QA/QC Sample Results 4-6
5.0 Groundwater Sampling Data Evaluation 5-1
5.1 Data Trend Analysis 5-1
5.1.1 Site 1 -Wastewater Settling Pond 5-2
5.1.2 Site 7-Station Landfill 5-3
5.2 Radiological Source Evaluation 5-5
5.2.1 Site 1:Wastewater Settling Pond 5-5
• 5.2.2 Site 7:Station Landfill 5-6
6.0 Conclusions and Recommendations 6-1
6.1 Site 1: Wastewater Settling Pond 6-1
6.1.1 Summary and Conclusions 6-1
6.1.2 Recommendations 6-2
6.2 Site 7: Station Landfill 6-2
6.2.1 Summary and Conclusions 6-2
6.2.2 Recommendations 6-3
7.0 References 7-1
Appendixes
Appendix A Rainfall Data and Well Survey Data
Appendix B Barometric Pressure and Water Level Data
Appendix C Serfes 1991
Appendix D Analytical Results of Equipment Rinsate
SCOT 83480017,DOC197
4
CONTENTS,CONTINUED
List of Tables
3-1 Rationale for Groundwater Sampling at Sites 1 and 7
3-2 Request for Analysis for the 1998 Groundwater Sampling Events
3-3 Proposed California Ambient Water Quality Criteria
3-4 Stationwide Upper Limit Background Values
4-1a-c Field Parameters Collected During Groundwater Purging at Sites 1 and 7
4-2 Analytical Results for Site 1 Wells, 1998 Sampling Events
4-3 Analytical Results for Site 7 Wells, 1998 Sampling Events
5-1 Groundwater Samples Exceeding both AWQC and Stationwide Background
5-2 Summary of Radiological Parameters Detected in Groundwater
A-1 Rainfall Data For Groundwater Monitoring Events 1 and 2.
A-2 Survey Data
B-1 Site 7 Barometric Pressure-Corrected Water Levels
B-2 Barometric Efficiency Calculation
B-3 Sites 1 and 7,February/March 1998 Groundwater Elevation Data
B-4 Sites 1 and 7,July 1998 Groundwater Elevation Data
B-5 Maximum PID Readings During Purging and Sampling in Sites 1 and 7
B-6 Sites 1 and 7 September 1993 Groundwater Elevation Data
D-1 Analytical Results of Equipment Rinsate
SCO19834800 17.DOC/97
CONTENTS,CONTINUED
List of Figures
1-1 Location Map
1-2 Site Locations
1-3 Wastewater Settling Pond
1-4 Site 7—Station Landfill
2-1 Surface Geology Locations of the Newport-Inglewood Fault Zone
2-2 Surface Features
2-3 Major Surface Water Hydrologic Features
3-1 Filtering Method—Well 07M01
4-1 Anaheim Bay Hydrographs
4-2 Site 1 Hydrographs
4-3 Site 7—07M01 Hydrographs
4-4 Site 7—W41 Hydrographs
4-5 Site 7—W44 Hydrographs
4-6 Site 7—W45 Hydrographs
4-7 Site 1 Mean Groundwater Elevations and Groundwater Gradient
4-8 Site 7 Mean Groundwater Elevations and Groundwater Gradient
5-1 Time Series Plots for Site 1 —Well 01M02
.•
5-2 Time Series Plots for Site 1 —Well 01M03
5-3 Time Series Plots for Site 1 —Well 01M04
5-4 Time Series Plots for Site 7—Well 07M01
5-5 Time Series Plots for Site 7—Well 07M02
5-6 Time Series Plots for Site 7—Well 07M03
5-7 Time Series Plots for Site 7—Well 07M04
5-8 Time Series Plots for Site 7—Well W39
5-9 Time Series Plots for Site 7—Well W41
5-10 Time Series Plots for Site 7—Well W42
5-11 Time Series Plots for Site 7—Well W43
5-12 Time Series Plots for Site 7—Well W44
5-13 Time Series Plots for Site 7—Well W45
5-14 Time Series Plots for Site 7—Well W46
SCOf98348OO17 DOC/97
N
Executive Summary
In 1998,CH2M HILL performed a Groundwater Monitoring Study under Contract N68711-
96-D-2299,Delivery Order No. 0005 for the Naval Facilities Engineering Command,
Southwest Division(SWDIV). Groundwater monitoring was conducted at Sites 1
(Wastewater Settling Pond)and 7(Station Landfill) of the Naval Weapons Station
(WPNSTA),Seal Beach(or Station),and consisted of two 3-week continuous water level
monitoring events and two groundwater sampling events.
Objectives
The objectives of the continuous groundwater level monitoring at Sites 1 and 7 are to:
• Evaluate whether the groundwater at Site 1 is tidally-influenced and,if so,assess the
direction of groundwater flow at Site 1 using continuous water level monitoring.
• Confirm the direction of groundwater flow at Site 7 during the wet season using
• continuous water level monitoring.
The objectives of the groundwater sampling are to:
• Evaluate the source of elevated levels of gross alpha in groundwater at Site 1 and the
source of gross alpha and gross beta in groundwater at Site 7 detected in the earlier
Remedial Investigation (RI) sampling effort.
• Assess the recent concentrations of metals above federal ambient water quality criteria
(AWQC)at Site 1 and the concentrations of metals and cyanide above federal AWQC in
groundwater at Site 7. All concentrations of metals and cyanide are also compared
against California AWQC.
Note that the AWQC are not directly applicable as groundwater cleanup criteria; they are
surface water criteria but not groundwater criteria. The AWQC were used in the RI for
general comparison purposes only.
Continuous Water Level Monitoring
Continuous water level monitoring was conducted at Sites 1 and 7 during two 3-week
periods in February/March 1998 and July 1998. The first monitoring event was conducted
during an unusually wet winter season (affected by what is commonly referred to as an "El
Nino"condition). The second monitoring event was conducted during a typically dry
summer season with no precipitation.
Tidal influence on shallow groundwater at Site 1 is slight and does not appear to
substantially impact either the general groundwater flow direction or its gradient. During
both monitoring events, groundwater flow was to the southwest in the general direction of
the Seal Beach National Wildlife Refuge (NWR). The gradient ranged from 0.0015 ft/ft
(February/March 1998) to 0.0016 ft/ft (July 1998). Based on the water level monitoring data,
5COt96357ppp1.DOCj97
ES-1
EXECUTIVE SUMMARY
! which were collected during two opposite sets of weather conditions, the groundwater flow
direction and gradient were remarkably similar. Consequently,seasonal variations in
f groundwater flow direction and gradient are unlikely to be dramatic.
Tidal influence on shallow groundwater levels at Site 7 were more pronounced than at
Site 1. A data reduction method was applied to the groundwater data to "filter out"
l fluctuations in water levels so that a mean water level for each well could be determined.
The groundwater flow direction varies considerably across Site 7. During the
February/March 1998 monitoring event,groundwater flow was to the southwest at a mean
gradient of 0.001 ft/ft. In July 1998, groundwater flow was to the southeast-east, at a mean
overall gradient of 0.0025 ft/ft. By comparison,monitoring data collected in September
•
1988 and November 1993 both indicated the groundwater flow direction was to the
•
northeast at gradients of 0.007 ft/ft and 0.002 ft/ft,respectively;no significant precipitation
were noted during these two previous monitoring events. Therefore,groundwater flow
appears to be generally away from the NWR during periods with no rainfall (dry season)
and generally towards the NWR during periods of significant rainfall (wet season). The
exact groundwater flow direction is determined by the interaction among hydrologic
features at or adjacent to Site 7,including the NWR tidal saltmarsh and the Orange County
Flood Control Channel.
Groundwater Sampling
Groundwater sampling was conducted at Sites 1 and 7 in June/July 1998 and September
1998. Additional water quality data were collected as part of the 1988 Site Inspection (Site 7
only)and the RI in 1993/1994 (Sites 1 and 7). The two groundwater sampling events in 1998
allow for a data trend comparison against historical groundwater sampling results.
There is no evidence to support that groundwater at Site 1 is currently impacted by site
activities. The data trends indicate sporadic detections of few metals that exceeded their
respective AWQC and background concentrations. Total selenium, dissolved copper,and
dissolved lead were detected above their AWQC and background concentrations in only
one of six sampling events at Site 1. Nickel appears to be the only metal consistently
detected above its AWQC and background concentration (in five of six sampling events).
Based on an evaluation of the results of radiological sampling at Site 1,the observed
radionuclides in groundwater at Site 1 are naturally occurring; there is no indication of
elevated radioactivity levels in groundwater associated with Station operations,nor will the
radioactivity levels pose health hazards to field workers.
The Site 7 groundwater quality data trends indicate sporadic detections of few metals that
exceeded their respective AWQC and background concentrations. The metals (dissolved)
detected at or above the AWQC include arsenic,cadmium,copper,lead,mercury,and
nickel. Cyanide was also detected above its AWQC in the 1994 sampling events with the
highest concentrations detected in wells located within landfill trenches (07M01 and 07M03).
However,cyanide was not detected in either of these two wells in the most recent
(September 1998) sampling event. Similar to the evaluation results of radiological sampling
at Site 1,the observed radionuclides in groundwater at Site 7 are naturally occurring; there
is no indication of elevated radioactivity levels in groundwater associated with Station
operations,nor will the radioactivity levels pose health hazards to field workers.
SCO 6357ooa.DOCI97
ES-2
EXECUTIVE SUMMARY
f ,
Recommendations
Groundwater at Site 1 flows in the general direction of the NWR. However, there is no
indication of groundwater contamination. No further groundwater monitoring activities,
either continuous water level monitoring or groundwater sampling, are recommended for
characterization of groundwater.
Site 7 was used by the Station to dispose of various wastes. Operations began at the site
more than 40 years ago and ceased about 25 years ago. Natural attenuation processes
appear to have been active over time. Although no well-defined plumes exist,water quality
data suggest Site 7 groundwater has been impacted by prior site activities. Therefore,
continued groundwater sampling at Site 7 is recommended. However,no additional
continuous water level monitoring is necessary.
SC01883570004 DOC/97
ES-3
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6.0 Conclusions and Recommendations
This section provides summaries and conclusions of two continuous water level monitoring
events and two groundwater sampling events conducted at Sites 1 and 7 in 1998. This
section also provides recommendations for future groundwater monitoring activities at the
two sites based on results of the most recent monitoring events,as well as historical water
level monitoring and water quality data collected between 1988 and 1994.
Continuous water level monitoring was conducted at Sites 1 and 7 during two 3-week
periods in February/March 1998 and July 1998. The first monitoring event was conducted
during an unusually wet winter season (affected by what is commonly referred to as an "El
Nino" condition). The second monitoring event was conducted during a typically dry
summer season with no precipitation. No previous continuous water level monitoring was
conducted at Site 1. Two previous continuous water level monitoring events were
conducted at Site 7 in September 1988 and November 1993.
Groundwater sampling was conducted at Sites 1 and 7 in June/July 1998 and September
1998. Additional water quality data were collected as part of the SI in 1988 and the RI in
1993/1994. The recent and historical water quality data allow for data trend analysis.
6.1 Site 1 : Wastewater Settling Pond
6.1.1 Summary and Conclusions
Tidal influence on shallow groundwater at Site 1 is slight and does not appear to impact
either the general groundwater flow direction or its gradient. During both monitoring
events, groundwater flow was to the southwest in the general direction of the NWR. The
gradient ranged from 0.0015 ft/ft (February/March 1998) to 0.0016 ft/ft (July 1998), typical
of groundwater flow that is not affected by manmade influences such as production
pumping. Based on the water level monitoring data,which were collected during two
opposite sets of weather conditions,the groundwater flow direction and gradient were
remarkably similar. By extension, seasonal variations in groundwater flow direction and
gradient are unlikely to be dramatic.
There is no evidence to support that groundwater quality at Site 1 is currently impacted by
prior site activities. The data trends indicate sporadic detections of few metals that
exceeded their respective AWQC and background concentrations. Total selenium,
dissolved copper,and dissolved lead were detected above their AWQC and background
concentrations in only one of six sampling events at Site 1. Nickel appears to be the only
metal consistently detected above its AWQC and background concentration(in five of six
sampling events). AWQC are recommended criteria for surface water but not groundwater.
Based on an evaluation of the results of radiological sampling, the observed radionuclides in
groundwater at Site 1 are naturally occurring. Although the gross alpha concentrations
exceeded the MCL of 15 pCi/L,there is no indication of elevated radioactivity levels in
SCO/963560003.DOC-97
6-1
6.0 CONCLUSIONS AND RECOMMENDATIONS
I
groundwater associated with Station operations,nor will the radioactivity levels pose health
hazards to field workers.
1 6.1.2 Recommendations
Groundwater at Site 1 flows in the general direction of the NWR. However, there is no
indication of groundwater contamination. No further groundwater monitoring activities,
• either continuous water level monitoring or groundwater sampling, are recommended for
characterization of groundwater.
6.2 Site 7: Station Landfill
6.2.1 Summary and Conclusions
Groundwater conditions at Site 7 are complex. Surface water features at or adjacent to the
site (i.e.,NWR tidal saltmarsh,Port of Long Beach mitigation ponds,OCFCC, drainage
ditch,and seasonal ponding due to rainfall)play major roles. Site 7 groundwater is affected
not only by Anaheim Bay tidal fluctuations but also by the influence that rainfall and tidal
fluctuations exert on these hydrologic features (see Section 2.3.2).
Tidal influence on shallow groundwater levels at Site 7 were more pronounced than at
Site 1. A data reduction method was applied to the groundwater data to "filter out"
fluctuations in water levels so that a mean water level for each well could be determined.
The groundwater flow direction varies considerably across Site 7. During the
1 February/March 1998 monitoring event,groundwater flow was to the southwest at a mean
gradient of 0.001 ft/ft. In July 1998, groundwater flow was to the southeast, then east,at a
mean overall gradient of 0.0025 ft/ft. Monitoring data collected in September 1988 and
November 1993 both indicated the groundwater flow direction was to the northeast at
gradients of 0.007 ft/ft and 0.002 ft/ft,respectively;no significant precipitation was noted
during these two previous monitoring events. It appears groundwater flow is generally
away from the NWR during periods with no rainfall (dry season) and is generally towards
1 the NWR during periods of significant rainfall (wet season). The exact groundwater flow
direction is determined by the interaction among the hydrologic features at or adjacent to
Site 7.
The Site 7 groundwater quality data trends indicate sporadic detections of few metals that
exceeded their respective AWQC and background concentrations. The metals(dissolved)
detected at or above the AWQC include arsenic,cadmium,copper,lead,mercury,and
nickel. Cyanide was detected above its AWQC in the 1994 sampling events with the
• highest concentrations detected in wells located within landfill trenches (07M01 and 07M03).
However,cyanide was not detected in either of these two wells in the most recent
(September 1998) sampling event. Again,AWQC are recommended criteria for surface
water but not groundwater.
Similar to the evaluation results of radiological sampling at Site 1, the observed
radionuclides in groundwater at Site 7 are naturally occurring. The concentrations of
Radium-226 (possible manmade source is instrument dial paint,if disposed at the site)
appear to be normal. Although the gross alpha concentrations exceeded the MCL of
15 pCi/L,there is no indication of elevated radioactivity levels in groundwater associated
• SCO/96 3560003.DDC-97
6-2
6.0 CONCLUSIONS AND RECOMMENDATIONS
{
with Station operations, nor will the radioactivity levels pose health hazards to field
workers. The gross beta concentrations in groundwater are comparable to the radioactivity
levels observed in seawater (300 pCi/L). Water level monitoring data and TDS levels in
groundwater support the finding that Site 7 groundwater quality is impacted by seawater
intrusion.
6.2.2 Recommendations
Site 7 was used by the Station to dispose of various wastes. Operations began at the site
more than 40 years ago and ceased about 25 years ago. Natural attenuation processes (e.g.,
dilution due to tidal "flushing") appear to have been active over time. Although no well-
defined plumes exist,water quality data suggest Site 7 groundwater has been impacted by
site activities. Therefore,continued groundwater sampling at Site 7 is recommended.
However,no additional continuous water level monitoring is necessary.
The following groundwater sampling program is recommended:
f
• Monitoring well network. All three wells located within the NWR (i.e., W41,W42, and
W43)will serve as "sentinel"wells for monitoring potential contamination from Site 7.
• Request for analysis for metals and cyanide. Several metals and cyanide have exceeded
their respective AWQC and background concentrations but the results indicate no
further need for radiological sampling.
• Five-year monitoring period. Sample for 5 more years and revisit the groundwater
sampling program at the end of the 5-year period.
• Sampling frequency. For the first year, sample semiannually, and annually thereafter
(for 4 years). Data from at least six sampling events are available and no increasing
trends in concentrations have been detected. One or more of the sampling events
should be conducted during periods of heavy rainfall when the groundwater flow
direction is expected to be towards the NWR. Testing of the water quality of the wells
located in the NWR would provide better measurements of potential impacts to the
aquatic community.
1
t
SC0/983560003.DOC•97 6-3