Does the open culvert support a violation being issued?
The culvert was a pre-existing road surface water drainage structure that is located outside of the excavation boundaries. Plans approved by NYSDEC called for the culvert to be capped as the excavation was backfilled, but to be isolated from the excavation using a plastic membrane prior to backfilling. All contaminated water collected in the excavation area is directed to a separate sump where it is then pumped to an on-site treatment unit. Once treated, the water is discharged to the sanitary sewer. Since no contaminated water was discharged into the culvert, there is no violation.
Since pipe was open when it should have been shut, can DEC require Conifer to inspect the pipes (all 3) for any sediments, and require samples at the outfall points?
As discussed above, all culverts were isolated from the remedial excavation. (name redacted)’s own photograph (attached) shows that no water is entering or in contact with the bottom of the lowest culvert pipe. As such, there is no need to request inspection nor sampling of the culvert outfalls.
As well, we would request that DEC take a field visit and photograph the pitfalls of all 3 pipes to look for evidence of recent discharges from pipes (wash out, sediment deposit, etc).
NYSDEC’s inspector has been present during all intrusive remedial activities at the site and has not noted any discharge of site water into the culverts. A sediment deposit would be expected at the culvert outfalls based on their prior use as drainage conveyance structures, and the presence of such deposits would not be an indication of an excavation-related impact.
Do we know if Conifer encountered more contamination than anticipated and if the scope of remediation (depth and linear extent) should be expanded?
The levels and limits of contamination encountered at the site so far are consistent with what was expected based on the site investigations and the Remedial Action Work Plan (RAWP.)
Is Conifer taking endpoint samples to confirm the soils are clean at the edges where the excavation ceases?
Documentation samples will be collected consistent with the Department’s approved RAWP. NYSDEC anticipates based on previous investigations that off-site migration of contamination is possible, and endpoint samples along certain boundaries of the site may not be “clean”. As discussed in the Decision Document for the site, off-site migration of contamination will be addressed separately by the NYSDEC’s Spill Response Program.
Lastly, will the occupants of the building will receive notification of 1) that they are living on top of a brownfield and 2) copies of testing performed at the site while they occupy it?
The site cleanup, when completed, will be protective of public health and the environment and, as identified in the Decision Document for the site, would allow the proposed development. The Final Engineering Report for the project will summarize the contamination remaining at the site, if any. Under New York State’s Tenant Notification Law, the results of soil vapor intrusion and indoor air sampling must be disclosed to tenants and occupants if test results exceed applicable standards or guidelines.