Aquifer: an underground layer of water-bearing rock and/or granular materials. Groundwater can be extracted using a water well.
Mulch: a blend of branches, stumps and other wood material from trees, pallets, and other clean wood waste, and large plants
Agency for Toxic Substances and Disease Registry (ATSDR): A federal public health agency within the United States Department of Health and Human Services. The agency focuses on minimizing human health risks associated with exposure to hazardous substances.
ng/L: nanograms per liter, or parts per trillion [ppt]
Biosolids: dewatered sludge (residual solids or sludge) generated during the wastewater treatment process and then processed through a composter to create biosolids
PFAS: Per- and polyfluoroalkyl substances. A group of manmade chemicals manufactured and used in a variety of industries since the 1950s.
Co-compost: a combination of WWTF output (residuals), leaf/yard waste, and municipal solid waste produced by Waste Options Nantucket. (Currently not being distributed to the public)
PFAS6 MCL: MassDEP’s drinking water MCL of 20 ng/L for the sum of six specific PFAS compounds: PFOS, PFOA, PFHxS, PFNA, PFHpA and, PFDA.
Compost: organic material that can be added to soil to help plants grow (typically food scraps and yard waste)
PFOA: perfluorooctanoic acid. A PFAS compound.
Confining unit: an underground layer of relatively dense, impermeable materials, such as clay, that may prevent transport of groundwater and pollutants deeper into the subsurface.
PFOS: perfluorooctane sulfonate. A PFAS compound.
FAQ: frequently asked questions
Translocate: the movement of a dissolved substance within an organism, such as plant parts (roots, stems, leaves, fruit)
MCL: maximum contaminant level. A standard established by MassDEP as the allowable level of a pollutant in drinking water
USEPA: United States Environmental Protection Agency
MassDEP: Massachusetts Department of Environmental Protection
WWTF: Wastewater Treatment Facility
MCP: Massachusetts Contingency Plan (310 CMR 40.0000). Lays out a detailed process on when and how contaminated sites must be assessed and cleaned up
Zone II Aquifer Wellhead Protection Area: represents the area of contribution to a water supply well under the most severe pumping and recharge conditions that can be realistically anticipated (180 days of pumping with no recharge from precipitation), per the MassDEP Drinking Water Regulations (310 CMR 22.000)