Operable Unit. II OU II consists of private and City-owned properties peripheral to the former mill site. Surveillance of OU II properties is conducted to ensure compliance with ICs that were implemented to preserve the OU II remedy for soil and groundwater. Observations for this quarter are: • Montezuma Creek Restrictive Easement Area (supplemental standards properties, both City-owned and privately owned): No evidence of nonconformance with land-use restrictions (no soil removal or construction of habitable structures in supplemental standards areas) was observed. • Groundwater-use restrictions (no installation of domestic-use xxxxx in the alluvial aquifer) were applied to several OU II properties under the 2004 covenant by which DOE transferred selected properties to the City of Monticello. No instance of nonconformance with this restriction was observed during the quarter. • Property MS-00211-VL (City-owned): No evidence of nonconformance with the land-use restriction on building construction was observed. • Pinyon-juniper supplemental standards properties (City-owned): No evidence of nonconformance with land- and groundwater-use restrictions was observed. • No storm events exceeding 2.8 inches of rain in a 24-hour period occurred to require nonroutine surveillance of supplemental standards cleanup properties. Climatological data for the quarter are included in Appendix C.
Operable Unit. III OU III consists of groundwater and surface water contamination resulting from operation of the former Monticello mill. Routine monitoring of OU III (water quality and water level) is performed semiannually in April and October. The contaminated groundwater is within the alluvial aquifer beneath the valley of Montezuma Creek; some sections of Montezuma Creek are contaminated by the discharge of contaminated groundwater. The alluvial aquifer has no record of past or present use; however, a portion of the aquifer is subject to ICs to restrict use. Montezuma Creek is used for limited irrigation and livestock watering. There are no ICs that affect surface water use. The groundwater remedy includes (1) monitored natural attenuation with ICs and
Operable Unit. II OU II consists of private and City-owned properties peripheral to the former mill site. LM conducts surveillance of OU II properties to verify compliance with ICs that were implemented to preserve the OU II remedy for soil and groundwater. Surveillance results for this quarter are: • Montezuma Creek Restrictive Easement Area (supplemental standards properties, both City-owned and privately owned). No evidence of nonconformance with land-use restrictions (no soil removal or construction of habitable structures in supplemental standards areas) was observed. • Groundwater-use restrictions (no installation of domestic-use xxxxx in the alluvial aquifer). These were applied to several OU II properties under the 2004 covenant by which DOE transferred selected properties to the City of Monticello. No evidence of nonconformance with this restriction was observed during the quarter. • Property MS-00211-VL (City-owned). No evidence of nonconformance with the land-use restriction on building construction was observed. Monticello NPL Sites FFA Quarterly Report: January—March 2016 U.S. Department of Energy Doc. No. S14013 April 2016 • Pinyon-juniper supplemental standards properties (City-owned). No evidence of nonconformance with land- and groundwater-use restrictions was observed. • No storm events exceeding 2.8 inches of rain in a 24-hour period occurred to require surveillance of supplemental standards cleanup properties for excessive erosion.
Operable Unit. If Dispute Resolution is not invoked within thirty (30) days after the Project Managers’ discussion concerning the modification, or if the need for modifying an Operable Unit is established through Dispute Resolution, the Operable Unit, as defined in Section II – DEFINITIONS, shall be modified.
Operable Unit. 1 (FTEUST-30)—Xxxxxx Creek. Hazardous substances, including PCBs, lead, and pesticides, have been released into Xxxxxx Creek. PCBs were found in fish and sediment samples. In addition, surface water sampling revealed elevated levels of lead and PCBs in the creek. Sampling conducted during the summer of 1999 showed PCB concentrations over 2,200 parts per million (ppm) in sediment. An Interim Removal Action (IRA) addressing PCB hot spot contamination was completed in June 2000. Over 6,600 tons of PCB contaminated sediments were removed and disposed off-site. The site was back filled to its original elevations with clean fill and re-vegetated with wetland plants. Since the IRA did not remove all of the contaminated sediments, a revised risk assessment will be part of the ongoing feasibility study (FS). In the spring of 2001, 41 sediment samples were collected and analyzed. Clams and mummichogs were also collected and analyzed from four locations within Xxxxxx Creek;
Operable Unit. 2 (FTEUST-29)—Xxxxx’x Lake. During a 1982 water quality study, the U.S. Army Environmental Hygiene Agency (USAEHA) observed fish with lesions in Xxxxx’x Lake. USAEHA recommended that the lake be off-limits to fishing. It has remained off-limits to fishing since that time. During subsequent investigations of Xxxxx’x Lake, sediment and water samples were collected and the biota of the Lake was examined. Pesticides, PCBs, and fuel hydrocarbons have been detected in the lake’s sediments. An Interim Removal Action (IRA) was conducted in 1999 to address the contamination at Xxxxx’x Lake. The IRA involved draining the entire lake, excavating sediments from the upper drainage ditch, placing sediments in the deeper portion of the lake, capping the bottom of the entire lake with two feet of clean fill, restoring the lake and re-stocking it with fish. Post-IRA monitoring and a feasibility study were completed in 2005. A Proposed Plan was released for public review and comment in August 2005. The Record of Decision was finalized in September 2007. The selected remedy calls for dredging or excavation of the Lake’s upper ditch, disposal of contaminated sediment off-site, construction of a storm water control system, long-term monitoring of various media (including surface water, sediment, benthic and aquatic organisms), and restrictions on land use;
Operable Unit. 5 (FTEUST-34)—The DOL Storage Yard. Hazardous substances, including pesticides and polyaromatic hydrocarbons (PAHs), have been released into soil and sediment directly under and surrounding the yard, and into the adjacent wetland and drainage swale areas. A Record of Decision (ROD) was issued for the DOL Storage Yard in 2001 to address these releases. The on-site remedial action work for this site was completed in 2003. EPA approved a Remedial Action Completion Report (RACR) for this site in June 2006;
Operable Unit. 6 (FTEUST-06)
Operable Unit. 7 (FTEUST-19)—The Oil/Sludge Holding Pond. Hazardous substances, including petroleum-related substances and heavy metals, have been released into sludge and soil at this site. In 2002, a ROD was issued for excavation and disposal of the contaminated sludge and soil. On-site remedial action was completed in 2004. EPA approved a RACR for this site in September 2006; and
Operable Unit. 9 (FTEUST-04) —Landfill #7, also known as South Landfill. Landfill #7 is a non-permitted landfill, because it ceased operation prior to VDEQ’s issuance of regulations requiring solid waste landfill permits. It was reported to have received waste (municipal solid waste, construction debris, paints, oils, pesticide and herbicide containers, and infectious/pathological waste) from 1951 to 1972 and contains two specific areas. Open burning was also conducted in the landfill. Sampling in 1977 showed degradation of groundwater due to landfill actives. Contaminants found at elevated levels include benzene, 1,1,2,2- tetrachloroethane, PCBs and metals. Groundwater studies in 1985, 1987, and 1988 showed low levels of metals, chlorobenzene, naphthalene, and 2-4-dinitrotoluene. A groundwater monitoring program was initiated in 1990. The landfill was capped in 1994. During a 1995 monitoring event, methane gas was detected at points outside the boundary of the landfill and near several on-post warehouses. To protect the safety and health of the occupants, a soil vapor extraction (SVE) system was installed and started operating in February 1998. The SVE system was designed to eliminate the migration of methane between the landfill and the warehouses. Methane gas monitors with alarms were installed in the five (5) nearby warehouses. Unsafe levels of methane gas have not been detected in the warehouses since SVE system operation began in February 1998.
