WATER QUALITY

Coakley Landfill Meeting April 14, 2016

A Greenland town meeting was held on April 14, organized by the Coakley Landfill Group, the EPA and the NH Dept. of Environmental Services. A summation of the EPA's position appears below, and is taken from their official site.

The Q & A provided the most interesting insight into how residential and commercial development stresses the ground water system, and may be affecting how the contaminants from Coakley spread. In my opinion, many attendees gained an understanding about how both residential and business water uses can affect the spread of contaminants.

The EPA did say there are ways to prevent the "flume" (surface groundwater that may contain contaminants) from spreading, and I thought this prompted one of the most valuable parts of the meeting because it helped local residents understand how important it is to weigh in on planning board review processes that can directly affect the safety of our drinking water and our quality of life. Greenland town officials, selectmen and planning board members attended and do appreciate and welcome everyone’s input while making these important decisions for Greenland.

There was a lot of information about water testing, contaminants and toxicity, and very detailed technical information is available through the NH DES and EPA. While we do live next to a Superfund site, there still are decisions and plans that we can make that help insure water quality for today and tomorrow.

Here's the EPA's overview of the Coakley Landfill site.

EPA’s Involvement at this Site
The privately owned landfill accepted municipal and industrial wastes from the Portsmouth area between 1972 and 1982. Incinerator residue was also accepted from the incineration recovery plant for a refuse-to-energy project between 1982 and 1985. The primary source of contamination is the landfill. VOCs and metals are the primary contaminants. On- and off-site surface water and groundwater are contaminated. The site is located on a groundwater/surface water divide, and residential wells to the south, southeast and northeast are contaminated with low levels of VOCs. Residential and commercial areas surround the site.

Since EPA issued its 1990 source control cleanup plan and its 1994 groundwater cleanup plan for the site, the acceptable level of arsenic in drinking water has changed to one fifth of what it was. EPA changed the arsenic standard for the site to match this new level. Since these cleanup plans were issued, the State of New Hampshire has updated its environmental regulations. For the source control cleanup plan, the chemical tetrahydrofuran has been added as an additional chemical of concern because groundwater monitoring detected this contaminant at levels exceeding state standards. In 2008, the site’s potentially responsible parties (PRPs) put in place groundwater restrictions and will continue to monitor groundwater quality at the site yearly until cleanup levels for all contaminants are met.

The site is being addressed through state, federal and potentially responsible party (PRP) actions. The provision of an alternate drinking water supply has reduced the potential for exposure to groundwater contamination. Since completion of the landfill cap in 1998, groundwater flows away from nearby residences and contamination levels are slowly declining.

EPA has conducted several five-year reviews of the site’s remedy. These reviews ensure that the remedies put in place protect public health and the environment, and function as intended by site decision documents. The 2011 five-year review indicated more analysis was needed to determine whether the groundwater monitoring zone should be expanded and more restrictions put in place. An April 2013 evaluation indicated that some wells should be sampled again for 1,4-dioxane, sampling could stop in other wells and the groundwater monitoring zone should be expanded.

Overall, the five-year review concluded that the remedy at the site protects human health and the environment in the short term. Long-term protectiveness has also been achieved at the source based on continued maintenance of the landfill cap, long-term monitoring and land use restrictions. Groundwater levels will also be protective when cleanup levels for all contaminants of concern are met and restrictions on the use of groundwater can be removed.

Last updated on April 15, 2016