An ORA Phase II, conducted at Camp Smith, New York in 2012, confirmed that lead was migrating off-range within surface water at levels that posed a risk to benthic organisms in the non-operational portion of Putnam Brook and the Camp Smith tidal marsh. In response to finding of the ORA Phase II, Army National Guard initiated a Supplemental Phase II to focus on evaluating the nature and extent of lead impacts to surface water and sediment in the tidal marsh and the potential risks to human and/or ecological receptors in the off-range area of the tidal marsh.
The Supplemental Phase II was conducted at Camp Smith in three phases between June 2014 and November 2015. The phased sampling included the collection of bulk chemistry data (metals in surface water/sediment), fish tissue for metals analysis, simultaneously extracted metals/acid volatile sulfide analysis (sediment), and geotechnical characterization. The Supplemental Phase II indicated that metals associated with upstream ranges were bound in on-range tidal marsh sediments and were unlikely to migrate off-range at concentrations that posed a risk to human health or the environment.
While the results of the Supplemental Phase II indicated that no metals were migrating from the operational ranges at levels that posed an unacceptable risk; and, the range configuration was expected to limit future lead deposition and/or migration of metals into Putnam Brook, the berm and Putnam Brook stream bed at the base of the berm remained a source of metals which needed to be addressed.
An investigation into the impact berm associated with Range 1A/1B was conducted. Projectile count data indicated that a significant mass of metals MC were present within the historical impact berm and Putnam Brook floodplain area associated with the range. X‑ray fluorescence results indicated that lead was binding to site soils and being mobilized from the range into Putnam Brook and the associated floodplain.
Based upon results of the investigation, a focused feasibility evaluation was performed to screen actions that could be implemented at the Camp Smith tidal marsh and Range 1A/1B to help mitigate off-range migration and potential future impacts to human health and the environment. Additionally, EA recommended that the other small arms ranges at Camp Smith be evaluated for the suitability of implementing range specific best management practices that could be implemented to limit migration of metals from on-range source areas.
It was recommended that the hot spots of contamination be removed and transported offsite for disposal and that an embankment be constructed upstream of Range 1A/1B to control stormwater and erosion. In addition, EA recommended that Camp Smith conduct annual monitoring of surface water and sediments to assess the potential for MC metals migration off the installation.
