Additional leachate treatment system at NY's Dewey Loeffel Landfill site.
County, New York.
According to EPA, the plant, which began operating in January 2014, is treating leachate seeping from the landfill and contaminated groundwater.
The agency explained that the new treatment system is being added to further address the long-term treatment of the chemical 1,4-dioxane, a stabiliser and solvent that is also a component of some cosmetics, detergents and shampoos.
Since the treatment plant began operating in January 2014, the EPA has required that the treated water be stored in a series of three on-site storage tanks and tested before each individual tank is discharged to the Valatie Kill.
This tank-by-tank process will continue until 7 to 10 days prior to delivery of the new treatment system, expected in late October.
In order for the new system to be installed, the storage tanks at the site will need to be removed. The EPA said that it will approve direct discharge from the plant to the Valatie Kill at that time, provided the sampling data continue to meet the stringent discharge limits set by the New York State Department of Environmental Conservation (NYSDEC).
The agency said that it anticipated that it will have sampling data from about 40 individual tanks by the time it allows any direct discharges from the treatment plant.
However, the plant needs to be kept running during the two to three week installation period to ensure that one of the treatment technologies in the plant that relies on microorganisms to treat the wastewater can continue to operate effectively. The EPA explained that the wastewater and leachate coming into the plant provide the nutrients these microorganisms need to survive.
After the new treatment system is installed the flow rate will be increased. Surface water will be sampled at least three times after direct discharge is approved.
The agency also explained that the slow start-up phase was intended to gradually bring the plant up to capacity to ensure that it is working effectively and is capable of meeting the discharge limits set by the NYSDEC.
To date 26 tanks have been sampled, analysed and individually discharged to the Valatie Kill. The EPA said that this comprehensive sampling program has demonstrated that the plant is working as intended. The majority of compounds tested for in the tanks that were discharged were said to have not been detected in the treated water and all have been below the requirements set by the NYSDEC for discharge to the Valatie Kill.
The carbon filtration system, which is a component of the existing treatment plant, was said to have been effectively removing 1,4-dioxane and will continue to be the primary treatment method for 1,4-dioxane until the new treatment technology is in place this fall. Prior to direct discharge, some modifications will be made to the existing sampling schedule. Sampling will meet and exceed the requirements set by the NYSDEC. While there is no discharge limit set for 1,4-dioxane at this time, the state requires quarterly monitoring. Sampling for 1,4-dioxane in the treated water will occur weekly, in excess of the requirement.
The Dewey Loeffel Landfill Site is located in southern Rensselaer County, New York, approximately four miles northeast of the village of Nassau.
The EPA said that from 1952 until 1968, the site was used for the disposal of an estimated 46,000 tons of waste materials generated by several Capital District companies including General Electric, Bendix Corporation (now Honeywell International) and Schenectady Chemicals (now SI Group).
The waste included industrial solvents, waste oils, polychlorinated biphenyls (PCBs), scrap materials, sludge and solids. Volatile organic compounds and other hazardous substances have seeped out of the landfill and contaminated the groundwater. PCBs have also moved downstream, causing contamination of sediment and several species of fish in and near Nassau Lake.
The treatment plant was built and is being operated by the two companies responsible for the cleanup, GE and the SI group, under a 2012 agreement with the EPA.
The added treatment is being installed because the EPA and the companies have agreed that adding the specialised treatment is the best long-term treatment option for 1,4-dioxane.
The final clean-up plan selected for the groundwater may include changes to the treatment plant and the new system is expected to be in place by November 2014.
Source Ben Messenger, Waste Management World
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|Publication:||Hazardous Waste Superfund Alert|
|Date:||Jul 31, 2014|
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