HomeMy WebLinkAboutCT 97-09; La Costa Lucky Sav-On Shopping Center; Tentative Map (CT) (7)Engineering, Corporate Office: 619.942.5147
Environmental Sciences and 605 Third Street Fax 619.632.0164
&.ASSOCIATES Management Services Encinitas, California 92024
A California Corporation
October 15, 1996 196269-12
Mr. Mike Bardin
Assistant General Manager
1960 La Costa Avenue
Carlsbad, CA 92009
RE: ARCO Station Contamination Impacts on LCWD Facilities
Dear Mike:
The Leucadia County Water District (District) has expressed concern that the District's pipelines in the
vicinity of the La Costa Avenue and El Camino Real intersection may have been impacted by the
petroleum hydrocarbon release at the former ARCO station. In this regard, Dudek & Associates, Inc.
has performed preliminary investigation of the status of the contamination problem at the former ARCO
Station through review of the County of San Diego's Hazardous Materials Management Division
(HMMD) files on this site.
There is concern regarding impact on the pipelines since petroleum hydrocarbons can permeate the
polyethylene encasement on the force mains and many types of joint gasket rubber. The extent to which
the contamination has impacted the force mains (polyethylene lined, gaskets), and the sewer pipe (gaskets
(and pipeline, if PVC)) is unknown. Furthermore, there exists the possibility that the petroleum
hydrocarbons may have traveled down pipeline trenches due to the higher hydraulic conductivity of the
pipe bedding material.
Presented below is a review of our findings.
SITE BACKGROUND
In 1985 the steel underground storage tanks (UST) at the ARCO station at 7654 El Camino Real were
removed. At that time, liquid phase hydrocarbons (LPH) were observed on the groundwater beneath and
adjacent to the removed gasoline USTs. Approximately 6,000 gallons of LPH and water were pumped
prior to the installation of four new fiberglass reinforced USTs.
Since 1991, HMMD has received quarterly ground water quality monitoring reports for the site. Between
1988 and 1985, approximately 31 soil boreholes and 12 groundwater monitoring wells were installed on
and off-site. A variety of information on groundwater levels, monitoring well locations, and contaminate
concentrations exist in the HMMD file.
In July 1995, the USTs were removed from the site. In an attempt to remediate the site, over 5,000
cubic yards of soil was excavated from the former ARCO facility in November, 1995. Due to adjacent
utilities, sidewalks, and driveways, some hydrocarbon-impacted soils with concentrations above 1,000
milligrams per kilogram (mg/kg) were not removed in two locations - one on the west sidewalk (along
El Camino Real) and one on the north sidewalk (adjacent to the La Costa Plaza driveway).
Mr. Mike Bardin Page2
Leucadia County Water District October 15, 1996
A review of the information in the HMMD files indicates the flow of groundwater to generally be in a
north, north-west direction towards Batiquitos Lagoon. Most of the remaining contamination is at the
west and north boundaries of the former ARCO station. A review of the fluctuating groundwater level
information indicates that at times the groundwater could have been above the bottom of the existing
District pipelines in the area.
There are four District pipelines which may be impacted: 24" Leucadia Force Main, 12" Failsafe Line,
18" gravity sewer and the 12" abandoned Vulcan Avenue Force Main. It does not appear from a review
of the data that contamination from the ARCO site will impact the proposed new 24" Parallel Leucadia
Force Main alignment south of the ARCO station on La Costa Avenue.
CURRENT STATUS
With the removal of most of the contaminated soil at the site, the concentrations of total petroleum
hydrocarbons (TPH) have been decreasing. Figure 1 depicts the current levels of contamination as of
August 1996. In an August 1, 1996 letter to Mr. Nasser Soinitof the HMMD, SECOR International Inc.
(SECOR), on behalf of ARCO Products Company (ARCO) requested closure of the site due to the
reduction in contamination levels. HMMD staff indicated in a conversation with Dudek that the site will
not be closed until contamination levels are reduced further.
The SECOR letter of August 1, 1996 indicates that the force mains and sewer lines "could be impacted
by hydrocarbons dissolved in groundwater," but that the District did not report hydrocarbon odors or
impact in the lines or the line trenches. Furthermore, the letter states: "Additional assessment in the area
of MW-13 would be limited because of the sewer lines. The Leucadia Water District has already
demonstrated their resistance to assessment adjacent to the sewer lines, therefore it is anticipated that
permission to perform additional assessment or excavation of a small volume of hydrocarbon impacted
soil is unlikely."
Dudek understands from discussions with District staff that, in fact, the District has been cooperative with
SECOR's efforts to assess the contamination close to the District's facilities. To our knowledge there
has been no resistance to further assessment adjacent to the sewer, in fact, the District should insist on
additional assessment and excavation.
RECOMMENDATIONS
We believe that SECOR has not satisfactorily proven that the District's force mains and sewer line were
not impacted by the contamination at the former ARCO site. The lack of the District reporting of odors
or problems with the lines does not indicate that the District's lines were not impacted.
There may be contamination in the old trench (beyond the edge of the ARCO site) of the abandoned 12"
force main which diagonally crosses the site. In fact, there may be contamination within the abandoned
pipeline which we understand was broken open during remediation excavation and then plugged with
concrete.
Mr. Mike Bardin Page 3
Leucadia County Water District October 15, 1996
We recommend that HMMD be requested to direct SECOR to propose methods and a schedule for the
approval of the District for SECOR to:
Remove all remaining contaminated materials up to, around, and beyond the existing pipelines,
while by-passing or keeping those pipelines in service. Fill and recompact the area with clean
granular materials.
Further inspect a portion of each force main and the sewer for possible deterioration of gasket
and polyethylene encasement material.
Immediately repair or replace any damaged LCWD pipelines for the full length of past
contamination impact.
We recommend that the District forward a copy of this letter to Mr. Nasser Soinit, HMMD, regarding
the District's concerns and recommendations for further contamination removal and utility inspection and
repair or replacement. We recommend that a copy of this letter also be forwarded by District staff to
Mr. Dwight Worden, District Attorney, for information and possible future action.
Because waterlines are generally installed shallower than sewer lines as indicated in the SECOR report,
adjacent waterlines may not have been affected. However, we recommend that a copy of this letter and
attachments also be forwarded by District staff to Mr. Bob Greaney, City of Carlsbad, for his possible
action with regard to potential impact on Carlsbad Municipal Water District waterlines.
If you have any questions, please call me at 942-5147.
Very truly yours,
DUDEK & ASSOCIATES, INC.
Steve Deering, California &fe. 26514
LCWD District Engineer
Attachments: List of Figures with References
Letter from Ms. Patricia McConnell, SECOR to Mr. Nasser Soinit, HMMD dated August 1, 1996
Mr. Mike Bardin Page4
Leucadia County Water District October 15, 1996
LIST OF FIGURES
Figure 3a Borings, Monitoring Wells, Cross-Section Lines, and Approximate Extent of Hydrocarbon-
Affected Soil
Reference: Alton Geoscience, Site Assessment Report, date March 11, 1993
Figure 7 Estimated Lateral Extent of Free Product and Benzene Plumes, and Ground Water Laboratory
Results (September 4, 1992)
Reference: Alton Geoscience, Site Assessment Report, date March 11, 1993
Figure 4 Remaining THP in Soil
Note: This figure does not show existing water lines (Dudek, 10/08/96).
Reference: Letter from Ms. Patricia McConnell, SECOR to Mr. Nasser Soinit, HMMD
dated August 1, 1996
UJcc
o
O
_i
UJ
— P _ HA-7
DISPENSER
PUMP
ISLANDS
HA-6
UNDERGROUND
STORAGE TANKS -^ 1 •- ^ '"
MW-1 I
...W-7
HA-8
A MW-6
-13
-12
f
1 1
/
/
ii STATION
I BUILDING
\
\
\
\
\
4-— T
HA-9
• •
^^\A/;
Oil
i
MW-
HA-2
\
MW-2 ',v?> ^>^ ^
LEGEND
HA-8 A. Hand Auger Boring
HA-12 A Hand Auger Slant Boring
B-5 0 Boring
MW-l -^- Monttorlng Well
A~~~A' Cross-Section Line
Affected Interval
4 fbg
Product Una
(approximate location)
ALTON GEOSCIENCE
5764 PACIFIC CENTER BLVD.
SUITE 101
SAN DIEGO. CA 92121
u
BORINGS, MONITORING WELLS,
CROSS-SECTION LINES, AND
APPROXIMATE EXTENT OF
HYDROCARBON-AFFECTED SOIL
NOTES: Figure redrawn from 1991 maps by EA Engineering,
Science, and Technology. All structure, boring, and
well locations are estimated, ppm = parts per million.
TPH = total petroleum hydrocarbons. Approximate
extent of adsorbed-phase plume based on 100 ppm
TPH. Interval depths are in feet below grade.
See Figures 4 and 5 for cross-sections.Scate(Feet)
ARCO Station 1939
7654 El Camlno Real
Carlsbad, California
FIGURE 3a
600130-20-SC2 9-30-92
MW-4
TPH
B
T
E
X
J
«t
ii
v
D2
1
<J
Jii
ND
ND
ND
ND
ND
/ DISPENSER /
.• PUMP
ISLANDS
1 B339
LEGEND
Monttorlna Well with
Benzene Concentration
In mg/l
_ JM.-Til.. :i4.
MW-5 Jk Monitoring Well with Free
(0.18)*~T" Product Thickness In Feet
/ ~ ". Estimated Lateral Extent
%.„>' of Free Product Plume
.•***/ Estimated Lateral Extent
; • of Benzene Plume* ; Greater than 0.001 mg/l
Product LJne
(approximate location)
Dlssoh/ed-Phase
Hydrocarbon
Concentrations In mg/I
ALTON GEOSCIENCE
5764 PACIFIC CENTER BLVD.
SUITE 101
SAN DIEGO. CA 92121
ESTIMATED LATERAL
EXTENT OF FREE PRODUCT
AND BENZENE PLUMES,
AND GROUND WATER
LABORATORY RESULTS
NOTES: Extent of plumes is interpretive based on data
collected September 4,1992; mg/l = milligrams
per liter; B = benzene; T = toluene; E = efriytbenzene;
X = total xytenes; NO = below detection limits stated
in official Laboratory Reports. For additional laboratory
results, refer to the Table. * = free product thickness in feet
September4,1992
ARCO Station 1939
7654 El Camlno Real
Carlsbad, California
FIGURE?
600130-20-SC2 10-6-92
LEGEND
HA-8 A HAND AUGER BORING
WW-11-^- MONITORING WELL
— S — SEWER LINE (6-9 ft. bgs\
FIBER OPTIC LINE (WAX. 3 ft. fag's) *
TRAFFIC SIGNAL LINE (WAX. 3Xft. bgs)
ELECTRICAL LINE (WAX. 3 ft. bgs)
SOIL SAMPLE LOCATION
TOTAL PETROLEUM HYDROCARBONS
MILLIGRAMS PER KILOGRAM
ESTIMATED AREAS OF REMAINING HYDROCARBONS
NOTE: BASE WAP, INCLUDING SITE DIMENSIONS AND WELL/
BORING LOCATIONS. MODIFIED FROM ALTON GEOSCIENCE. 1994.
APPROXIWATE SCALE IN FEET
NOTE: ALL LOCATIONS AND DIMENSIONS ARE APPROXIMATE
BASED ON AVAILABLE DATA.
SECOR
1939TP4.DWG
REMAINING TPH IN SOIL
FORMER ARCO FACILITY #1939
7654 EL CAMINO REAL
CARLSBAD, CALIFORNIA
PROJECT No.:
80600-017-13
FIGURE: 4
LEGEND
FAH.SAFE 12" ACP
24" DIP
24" VCP GRAVITY
ELEVATIONS
A
City of Carlsbad
Planning Department
November 21, 1996
Tom Hageman
Planning Systems Suite 100
2111 Palomar Airport Road
Carlsbad, CA. 92009
SUBJECT: LA COSTA PLAZA - PRE 96-56
APN: 216-124-02
A preliminary review of your project was conducted on November 14, 1996. Listed
below are the issues raised by staff. Please note that the purpose of a preliminary
review is to provide you with direction and comments on the overall concept of
your project. The preliminary review does not represent an in-depth analysis of
your project. Additional issues of concern may be raised after your application is
submitted and processed for a more specific and detailed review.
Planning:
1. The General Plan Land Use Map identifies a portion of the proposed site as
being Open Space. However, this designation seems to be in conflict with
the existing La Costa Plaza development. Therefore, In order to help
facilitate an administrative determination of the land use boundaries, a
constraints map should be submitted identifying "constrained land", flood
plain, and other natural features. In addition, the LCWD parcel has a General
Plan designation of Public Utilities. Use of parcels with either Open Space
or Public Utilities designations will require a General Plan Amendment.
2. The property abuts the El Carriino Real corridor and is therefore subject to a
Special Use Permit.
3. Gas stations are allowed within the neighborhood commercial zone with a
Conditional Use Permit.
4. The site has a Neighborhood Commercial zoning with a "Q" overlay which
means that a Site Development Plan must be processed for the any
development.
2O75 Las Palmas Dr. • Carlsbad, CA 92009-1576 • (619) 438-1161 • FAX (619) 438-O894
)MiPRE 96-56 LA COMR. PLAZA
November 21,1996
PAGE 3
14. A traffic study may be required to determine if additional improvements are
warranted on La Costa Avenue, such as:
• Eliminating the left turn move out of the proposed driveway on La Costa
Avenue;
• Providing an unsignalized dual left turn lane on La Costa Avenue ;
• Widening the roadway in this area to improve sight distance;
• Installing a traffic signal;
• Providing a dedicated right turn lane for the driveway entrance;
• Median improvements.
15. The layout of the onsite circulation should be designed with obvious and
clearly defined points of access and main traffic aisles through the center.
This may be accomplished by providing wider traffic aisles, lane striping, and
having the aisles free of parking stalls to avoid conflicts between through
traffic and vehicles backing out.
16. Circulation for the gas station site should be designed to avoid conflicts with
traffic using the driveway entrance on El Camino Real.
17. The alignment in front of the Water District offices appears awkward and
could be confusing to drivers.
18. Truck turning radii should be plotted on the site plan to demonstrate that
trucks can safely access the loading area. This may require larger radij on the
raised curb islands in the vicinity of the loading area.
19. The filing of a boundary adjustment plat will be required for the proposed land
trade with Leucadia County Water District.
20. The site plan should include a plotting of the 100-year base flood elevation for
the before and after development condition. Since this property is located
within the 100-year flood plain, the proposed development will also require the
filing of a Special Use Permit: Floodplain application.
21. Future project plans should identify the drainage pattern for the site and
include measures to treat surface runoff onsite prior to entering the public
storm drain system.
This issue is related to the City's requirements of the National Pollutant Discharge
Elimination System (NPDES) permit, which requires a project to provide best
management practices to reduce surface pollutants to an acceptable level prior to
discharge. Methods found to be acceptable include directing runoff from paved
November 18, 1996
TO: CHRISTER WESTMAN, ASSOCIATE PLANNER
FROM: Associate Engineer Quon
VIA: Principal Civil Engineer
/
LA COSTA PLAZA, PRE 96-56
We offer the following comments:
1. With regard to access off El Camino Real for this particular site plan, one driveway
opening will be allowed with right and left turns in, and right turns out. This driveway
opening will require the construction of a deceleration lane along the project frontage.
2. Any discretionary application for development of this site will include conditions of
approval to provide the following frontage improvements:
* Sidewalk, curb, and gutter along El Camino Real and La Costa Avenue;
+ Raised concrete landscaped median on El Camino Real;
» Dedication of right-of-way and installation of a deceleration lane fronting the
project on El Camino Real;
» Dedication of 13' of right-of-way and installation of a dedicated right-turn lane on
La Costa Avenue.
3. A traffic study may be required to determine if additional improvements are warranted
on La Costa Avenue, such as:
» Eliminating the left turn move out of the proposed driveway on La Costa Avenue;
* Providing an unsignalized dual left turn lane on La Costa Avenue ;
* Widening the roadway in this area to improve sight distance;
» Installing a traffic signal;
* Providing a dedicated right turn lane for the driveway entrance;
* Median improvements.
4. The layout of the onsite circulation should be designed with obvious and clearly defined
points of access and main traffic aisles through the center. This may be accomplished
by providing wider traffic aisles, lane striping, and having the aisles free of parking stalls
to avoid conflicts between through traffic and vehicles backing out.
5. Circulation for the gas station site should be designed to avoid conflicts with traffic using
the driveway entrance on El Camino Real.
6. The alignment in front of the Water District offices appears awkward and could be
confusing to drivers.
7. Truck turning radii should be plotted on the site plan to demonstrate that trucks can safely
access the loading area. This may require larger radii on the raised curb islands in the
vicinity of the loading area.
8. The filing of a boundary adjustment plat will be required for the proposed land trade with
Leucadia County Water District.
9. The site plan should include a plotting of the 100-year base flood elevation for the before
and after development condition. Since this property is located within the 100-year flood
plain, the proposed development will also require the filing of a Special Use Permit
application.
10. Future project plans should identify the drainage pattern for the site and include
measures to treat surface runoff onsite prior to entering the public storm drain system.
This issue is related to the City's requirements of the National Pollutant Discharge
Elimination System (NPDES) permit, which requires a project to provide best
management practices to reduce surface pollutants to an acceptable level prior to
discharge. Methods found to be acceptable include directing runoff from paved areas
towards a landscaped swale prior to reaching the storm drain; or installing an onsite
drainage basin specially designed to remove pollutants.
Please forward the red-lined check print to the applicant. If you have questions regarding any of
the comments above, please contact me at extension 4380.
KENNETH W. QUON
Associate Engineer