2.1.1 Narrative
Surface soil (0-1’ bg) contained lead above 350 ppm, the level of
concern, in five of the seven designated
playground areas within the housing complex, the public raised garden bed area,
and one private garden. The average
concentration of lead in the five play areas was 635 ppm. In most cases, this removal action was
limited to removing the top foot of contaminated soil and replacing it with
clean fill in the playgrounds as well as the identified gardens. In 2 of the playground grids, the play areas were
raised in a manner similar to the raised garden beds.
2.1.2 Response Actions to Date
Please refer to
the map located in the documents section of the website www.epaosc.org/MedfordHousingAuthority for the locations
of the specific grids.
Please refer to
earlier POLREPs for response actions prior to November 16, 2016.
November 16-20, 2015:
Excavation began
in grid-3 but was temporarily halted when an active gas line was discovered
within 3’ of the ground surface. This
normally would not have been discovered as the removal is concentrating on
removing the top foot of soil. A tree
however had been removed from that location and the gas line was found when the
stump and roots were being removed. The
gas utility company was immediately called and arrived soon afterwards. The pipe was not compromised, no leaks were
detected, and after the exposed section of pipe was rewrapped, the entire
excavation was backfilled;
Transportation and
disposal (T & D) began this week as lead-contaminated soil, which was
stockpiled in the ballfield (grid 1), was transported to a Waste Management
Landfill in Rochester, NH along with one roll-off box full of discarded
playground equipment and one box of tree stumps;
A number of stumps
from trees that had been previously removed were ground down to below grade.
November 23-December 4, 2015 (includes break for Thanksgiving):
T & D of soil
continued;
Excavation of
grid-3 was completed and backfilling of this grid commenced.
December 7-12, 2015:
T & D of soil
continued as well as backfill in locations previously excavated. T & D was halted on December 9 however
when EPA was notified that the landfill had not received the analytical to
support additional tonnage. Upon
investigation, the subcontracted laboratory had failed to run the samples they
were supplied with and therefore, the amount of soil being transported was not
supported by the appropriate data. Once
the samples were run, one set of analytical indicated that the concentration of
lead (11,000 PPM) had greatly exceeded the criteria for the landfill to use the
soil for daily cover (2,000 PPM). As this
concentration was much higher than every one of hundreds of samples previously
collected and analyzed, the lab was contacted and asked to re-run that sample;
December 14-19, 2015:
The sample was
re-analyzed and the concentration was once again at the expected average of
approximately 600 PPM. The OSC explained
the situation to the landfill and the anomalous higher concentration was
attributed to a minute lead particle(s) that ended up in the aliquot used for
the analysis. Subsequent samples also indicated lead concentrations well below
1,000 PPM. T&D began again on
December 18;
Backfilling with
loam continued.
December 21-22, 2015:
T & D
continued and plans were made for EPA’s contractor to return to the site after
the New Year to at a minimum complete T & D of the remaining pile of
contaminated soil. The site was secured
in case weather conditions did not allow for a remobilization prior to the
spring.
January 5 - 19, 2016:
Weather conditions
remained satisfactory allowing EPA’s contractor to remobilize to the site on
January 4. T & D started up again on January 5 and the remaining pile was
shipped off-site by January 9. The
footprint of the pile was leveled out, geotech fabric layed down, and the area
backfilled with a base gravel layer. The
contractor demobilized for the winter although the remaining heavy equipment
was not picked up until January 19.
Air monitoring has been conducted in all locations
where intrusive activities involving contaminated soil occurred. This is to ensure that contaminated soil/dust
is not being generated and/or released during removal activities.
None of the playground equipment located in the 4
grids could be salvaged as it had been in place for many years. The equipment had deep and expansive footings,
was rusted to a point where they could not be dismantled and moved, and was no
longer to the present code required for commercial playgrounds. Therefore, the equipment will eventually be
replaced.
2.1.3 Enforcement Activities, Identity of Potentially Responsible Parties (PRPs)
See POLREP 1 for details
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