HomeMy WebLinkAboutRS_Site Assessment for Contamination_180629_v1.pdfSTEMENENVIRONMENTAL, INC.
P.O. BOX 3644
LACEY, WASHINGTON 98501-8212
CONTR. LIC. #STEMEEI081J9
Telephone 360-438-9521 Fax 360-412-1225
April 23, 2018
Mr. Dale Walker
D & C Investments, LLC
555 SW Grady Way
Renton, Washington 98057
Dear Mr. Walker:
RE: LIMITED PHASE II ENVIRONMENTAL SITE ASSESSMENT, GROUNDWATER
MONITORING WELL INSTALLATION, AND GROUNDWATER MONITORING
INFORMATIONAL LETTER FOR THE COMMERCIAL PROPERTY LOCATED AT 3400
EAST VALLEY ROAD, RENTON, WASHINGTON.
TAX PARCEL #302305-906
1.0 Site Characteristics
The assessed property, herein described as the subject property, is composed of 5.65
acres (246,114 square feet) of commercially developed property located at 3400 East Valley
Road, Renton, Washington. The King County Assessor’s Office lists the subject property as Tax
Parcel #302305-9067.
Based on the review of aerial photos, Polk Street Directories, knowledgeable individuals,
and information obtained from the King County County Assessor's Office, it appears that for
approximately 64 years the subject property has been primarily occupied by an automotive
wrecking yard and/or radiator shop.
Available information indicates that in earlier years, the property was vacant
undeveloped farm/agricultural land.
The subject property is located in an area primarily occupied by commercial/industrial
properties and a State Highway.
A Wetland is located along the eastern boundary of the subject property.
Current development of the subject property consists of a single story, 4,000 square foot
Pre-Fabricated steel ware house building and an approximately 1,100 square foot radiator shop.
The radiator shop structure is a three sided, covered building built on a concrete slab.
The subject property is serviced by public utilities.
RECEIVED
06/29/2018
amorganroth
PLANNING DIVISION
2
A large portion of the gravel/dirt surface property is used for the storage of disabled/junk
cars, associated car parts, and petroleum products liquid storage containers.
The perimeter of the property is secured by a chain link security fence.
2.0 Investigative Soil and Groundwater Sampling Projects
On March 29 and March 30, a total of twenty-nine (29) borings were advanced at
selected locations on the subject property.
On February 15, 2018, twenty (20) additional soil borings were at selected locations on
the subject property
The borings were advanced to approximate depths of 10 feet b.g.s. or less at selected
accessible locations throughout the subject property.
Soil samples were obtained from various depths at each sampling location.
Groundwater samples were obtained from eight (8) of the borehole sampling locations.
Additionally, one (1) groundwater sample was obtained from an "out of service" water
well located along the southern portion of the western perimeter of the subject property. The well
was discovered during on-site investigations in the immediately surrounding areas.
After the water in the well was sampled and the receipt of laboratory analyses results, the
well was property closed/abandoned by Licensed Well Drillers from Holt Services Inc.
Soil samples were field screened using a water sheen test and a Photo-ionization Detector
(PID).
A total of forty-five (45) soil samples and nine (9) water samples were submitted for
extended laboratory analyses based on on-site observations and field screening results.
3.0 Preliminary Investigations Findings
The surface soils and very shallow subsurface soils present on large sampled portions of
the subject property are oil stained and require removal and proper off-site disposal. The soils
present at depths of 4 ft. b.g.s. (below ground surface) or greater in many of these areas do not
contain petroleum range contaminates and/or VOCs at levels that exceed MTCA Method A
Clean Up Levels and would not require removal.
The results of these environmental investigations report no presence of Hexavalent
Chromium (Chrome VI) in the shallow subsurface soils on the subject property.
Area #1 - North Central Portion of Site
The subsurface soils present at depths up to at least 10 ft. b.g.s., in an area occupied by
liquid storage drums on the central northern portion of the subject property (Sampling Location
3
S-8), contain gasoline range petroleum contaminates at levels that exceed MTCA Method A
Clean Up Levels.
The groundwater sampled at sampling location S-8 contained gasoline range TPH (total
petroleum hydrocarbons), Benzene, and MTCA 5 Metals at levels that exceed MTCA Method A
Clean Up Levels.
Area #2 - Radiator Shop Area
The shallow subsurface soils located in areas directly surrounding the on-site radiator
shop building and the adjacent liquid storage drum area contain VOCs (volatile organic
compounds), gasoline range TPH, diesel fuel range TPH, and lube oil range TPH and Lead that
exceed MTCA Method A Clean Up Levels.
The groundwater in areas directly surrounding the on-site radiator shop building contain
MTCA 5 Metals at levels that exceed MTCA Method A Clean Up Levels.
Area #3 - Southern Portion of Western Perimeter of Site
A liquid drum storage area and a few small automobile work area compounds are located
on this portion of the site. Aerial photos depict that portions of this area periodically serve as a
storm water collection area for oily storm waters.
An "out of service" 8 inch diameter steel well casing was found along the western
perimeter of this area. The well casing appears to extend to an approximate depth of 80 ft. b.g.s.
The shallow surface soils in this area contain lube oil range TPH and VOCs at levels that
exceed MTCA Method A Clean Up Levels.
Water samples S-20-W and S-24-W reported the presence of Metals at levels that exceed
MTCA Method A Clean Up Levels.
Water sample S-W-W was obtained from the waters present in the "out of service" well
casing. Laboratory analyses results for water sample S-W-W report no presence of gasoline
range TPH, diesel fuel range TPH, lube oil range TPH, Metals, and/or VOCs ar levels that
exceed MTCA Method A Clean Up Levels.
The “out of service” well casing was properly abandoned/closed by Licensed Well
Drillers from Holt Services Inc.
Area #4 - Storm Water Pond Portion of the Site
A storm water collection pond is located on the central southern portion of the site. The
storm waters were pump from this collection pond for permitted discharge. In earlier years the
waters were pumped/transferred to a treatment cell consisted of layers of oyster shells located
near the southeast corner of the subject property and then were released into the wetland/stream
area that borders the eastern portion of the property. In recent years the waters collected in the
pond were pumped/transferred into a catch basin that is located near the southwestern portion of
the property. The catch basin discharged to the City of Renton sewer.
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Laboratory analyses results for soil samples obtained from the shallow soils in the areas
surrounding this pond reported no presence of gasoline range TPH, diesel fuel range TPH, and/or
lube oil range TPH.
Laboratory analyses results for groundwater sample S-26-W, obtained from the shallow
groundwater in the areas near the pond reported the presence of lube oil range TPH, Metals and
Vinyl Chloride at levels that exceed MTCA Method A Clean Up Levels.
Area #5 - Eastern Boundary of Site
Laboratory analyses results for investigative groundwater sample S-17-W, obtained from
a location along the central portion of the eastern perimeter of the site, reported the presence of
Lead at levels that exceed MTCA Method A Clean Up Levels.
Laboratory analyses for investigative soils sample S-18-3, S-18.5-2, and S-18.5-4
confirmed the presence of gasoline range TPH, lube oil, Benzene, and/or Metals at levels that
exceed MTCA Method A Clean Up Levels in the shallow soils present along the southern
portion of the eastern perimeter of the site.
Laboratory analyses results for investigative groundwater sample S-18-W, obtained from
a location along the southern portion of the eastern perimeter of the site, reported the presence of
Arsenic at levels that exceed MTCA Method A Clean Up Levels.
On March 15, 2018, a total of six (6) test pits were recently excavated along the Eastern
Boundary of the subject property and directly adjacent to the neighboring wetland area.
Solid waste/metal debris was encountered at various depths during the excavation of the
test pits which restricted deeper excavation in selected pits.
Laboratory analyses results for test pit soil samples R1-2, R1-2.5, R1-4, R3-5, confirmed
the presence of gasoline range TPH and/or BTEXs at levels exceeding applicable MTCA Clean
Up Levels at various depths in test pits R1 and R3.
Groundwater flowed into the lower portions of these test pits.
Groundwater Monitoring Well Installations and Groundwater Monitoring Events
On August 9 and August 10, 2017, and March 9, 2018, eight (6) groundwater monitoring
wells were installed at selected locations on the subject property. The wells were installed by
licensed well drillers using a truck mounted rotary auger drill ring supplied by Holt Services Inc.
The elevation of the Top of Casing in each monitoring well was professionally surveyed
by DOWL.
Groundwater samples were obtained from each of the six (6) of on-site groundwater
monitoring wells on August 25, 2017. Groundwaters were present at depths ranging from 3.416
to 7.226 feet b.g.s. Groundwater elevation measurements and groundwater sampling services
were provided by Blaine Tech.
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Mr. John Kane, Washington State Licensed Hydrogeologist #1193, determined the
direction of groundwater flow was to the west on this date.
Groundwater samples were obtained from each of the six (6) of on-site groundwater
monitoring wells on January 25, 2018. Groundwaters were present at depths ranging from 1.106
to 5.346 feet b.g.s. Groundwater elevation measurements and groundwater sampling services
were provided by Blaine Tech.
Mr. John Kane, Washington State Licensed Hydrogeologist #1193, determined the
direction of groundwater flow was to the northwest on this date.
Laboratory analyses results for groundwater samples MW1, MW2, MW3, MW4, MW5,
and MW6 reported no presence of the site’s contaminants of concern at levels exceed MTCA
Method A Clean Up Levels.
On March 9, 2018, groundwater monitoring wells MW7 and MW8 were installed at
selected locations on the western portion of the subject property near East Valley Road.
Laboratory analyses results for water samples obtained from these two (2) newly installed
wells reported no presence of the site’s contaminants of concern at levels exceed MTCA Method
A Clean Up Levels.
Groundwater elevation measurements obtained during the groundwater sampling events
indicate that the direction of groundwater flow is to the west in the dryer seasons (lower
groundwater elevations) and to the northwest in the wetter seasons (higher groundwater
elevations).
4.0 Summary:
The results of these environmental investigations report no presence of Hexavalent
Chromium (Chrome VI) in the shallow subsurface soils on the subject property.
The results of the recent on-site investigations of the shallow subsurface soils have
identified the above listed areas of concern where the confirmed presence of gasoline range TPH,
lube oil range TPH, and/or VOCs, at levels that exceed applicable clean up levels extends to
depths up to 10 ft. b.g.s. on selected portions of the subject property.
The results of the recent on-site investigations of the shallow subsurface soils and
groundwater have identified the above listed areas of concern where the confirmed presence of
gasoline range TPH, lube oil range TPH, and/or VOCs, at levels that exceed applicable clean up
levels is restricted to surface and subsurface soils present at depth of 2 feet b.g.s. or lees on a
large portion of the subject property.
The results of the recent on-site probe investigations of the groundwater, present at
selected locations on the subject property, have identified the above listed areas of concern
where the presence of gasoline range TPH, lube oil range TPH, and/or VOCs, at levels exceeding
MTCA Method A Clean Up, are present in the groundwaters sampled using a probe.
6
Groundwater samples obtained from each of the eight (8) on-site groundwater
monitoring, wells reported no presence of the site’s contaminants of concern at levels that exceed
MTCA Method A Clean Up Levels.
The results of these investigations indicate that on many sampled portions of the subject
property, the contaminated soils in these areas are limited to depths of 4 feet b.g.s. or less. Also,
in some of these areas, the adversely impacted soils are limited to depths of 1 feet b.g.s. or less.
Sincerely,
Paul W. Stemen
Vice President
East Valley RdMW-6
MW-2
MW-3
MW-1
MW-4
MW-5
14.16'
13.87'
15.05'
14.27'
14.47'
14.53'
14.0'14.25'14.5'14.75'15.0'
Figure 1
Groundwater Elevation
Contours
Phase II Environmental Site Assessment
3400 East Valley Road
Renton, WA
N
Approximate Location of Property Boundary
Project No. 51213
Approximate Building Outline
Approximate Location of Fencing
Approximate Location of
Groundwater Monitoring Well
and Groundwater ElevationMW-2
15.05'
Estimated Groundwater Elevation Contour Wells Surveyed on 8/30/17
A
B