SWMU 2 - Causeway Landfill CERCLA Landfill Site
Background
SWMU 2 was a former landfill that was operated from the mid-1950s to the early 1960s. The landfill is about 4 to 6 feet thick. It is located about 7 miles from downtown on the eastern side of Clam Road on a narrow strip of land separating Clam Lagoon from Sitkin Sound. The landfill reportedly received waste materials that included sanitary trash, construction debris, scrap equipment, and other refuse generated by NSGA. Site features are generally flat, with a predominantly cobble and gravel surface cover. The Causeway Landfill is approximately 6.36 acres (US Navy 1995c).
The remedial action objectives for SWMU 2 are to protect human or ecological receptors (or both) from exposure to landfill debris and soil. Maintaining the integrity of the soil cover will help ensure the site remains protective.
Landfill Institutional Controls
ICs at the landfills complement previous actions taken, such as installation of groundwater monitoring systems, and the placement of soil cover. The ICs will minimize potential human exposure to site chemicals by implementing land use restrictions and imposing restrictions on soil excavations.
To ensure the integrity of the landfill covers, containment, and monitoring systems currently in place, the future landowner(s) and/or user(s) will be prohibited from performing activities that will disturb the soil cover or monitoring systems or impact the drainage and erosion controls developed to protect the soil cover.
|
|
Groundwater Restrictions
Domestic use of groundwater in the Downtown Area is restricted because of the potential presence of petroleum compounds and other chemicals in the groundwater. Domestic groundwater use is defined as that used by households or transients for human and animal consumption, cooking, bathing, showering, gardening, irrigation, or use on consumable food products, watering animals and any other domestic use. The excavation notification program at individual sites provides one barrier to drilling; enforcement of the prohibition will also occur through periodic visual inspections. The visual inspections will focus on unauthorized wells in the restricted area. Groundwater use restrictions are included in the equitable servitude.
|
Inspections and Reporting
The ICs identified in this plan will be inspected and reported on an annual basis, or as necessary. Signs will be inspected for wear and tear, and replaced as necessary. The annual reports will assess the need for more or less inspection requirements, as well as determine whether the ICs in place are effective. The annual reporting requirements will be included in CERCLA 5-year reviews.
|
Land Use Restrictions
The landfills may be used for recreational use or any other activity that does not adversely impact the integrity of the landfill covers, containment, or monitoring systems. Examples of acceptable recreational uses include hiking, bird watching, hunting, nature watching, or any other short-term, non-intrusive activity.
|
Soil Excavation Restrictions
Landfill excavation by non-Navy personnel is absolutely prohibited. Excavation for the purpose of digging a domestic groundwater use well is also prohibited. Recreational land uses that add additional cover (e.g. ball fields, golf course) may be permissible. Navy personnel will be allowed to excavate for the purposes of repairing caps, etc.
|
Landfills Engineering Controls
The following engineering control, as stipulated in the OU A ROD, is required at landfill sites.
Sign and Soil Cover Maintenance
Signs and soil cover are in place at the landfills. The signs and soil cover will be inspected annually, or as necessary, to ensure that the signs are legible, and that the soil cover remains in place.
|
