Connecticut Aquifer Protection Act Glossary: Key Terms & Definitions for Developers and Consultants

Connecticut Aquifer Protection Act Key Terms & Definitions

Aquifer Protection Area (APA): A designated area surrounding an active public water supply well in a stratified drift aquifer that serves more than 1,000 people, as defined in the Connecticut Aquifer Protection Act.1

Best Management Practices (BMPs): Practices, procedures, or structures designed to prevent or minimize the risk of groundwater contamination from regulated activities within Aquifer Protection Areas.2

Delineation: The process of identifying and mapping the boundaries of an Aquifer Protection Area, as carried out by the Commissioner of Energy and Environmental Protection in cooperation with the Commissioner of Public Health and affected water companies.3

Groundwater: Water beneath the surface of the ground, often found in aquifers and accessed through wells for drinking water and other uses.4

Hazardous Material: Any substance or combination of substances which, because of quantity, concentration, or physical, chemical, or infectious characteristics, may cause or significantly contribute to an increase in mortality or an increase in serious irreversible or incapacitating reversible illness, or pose a substantial present or potential hazard to human health or the environment when improperly treated, stored, transported, disposed of, or otherwise managed.5

Hazardous Waste: A solid waste that exhibits any of the characteristics of hazardous waste identified in 40 CFR Part 261, Subpart C, or is listed as a hazardous waste in 40 CFR Part 261, Subpart D.6

Land Use Restriction: A prohibition or limitation on certain activities or development within an Aquifer Protection Area, as established by the Connecticut Aquifer Protection Act and local aquifer protection regulations.7

Municipal Aquifer Protection Agency: The agency responsible for implementing and enforcing the Connecticut Aquifer Protection Act at the local level, typically the municipal planning and zoning commission or inland wetlands agency.8

Performance Standard: A requirement established by the Connecticut Aquifer Protection Act or local aquifer protection regulations that specifies the manner in which a regulated activity must be conducted to minimize the risk of groundwater contamination.9

Public Water Supply Well: A well used to supply drinking water to a public water system serving at least 25 people or having at least 15 service connections.10

Regulated Activity: Any action or process within an Aquifer Protection Area that involves the use, storage, handling, or disposal of hazardous materials or waste and poses a significant risk to groundwater quality, as identified in the Connecticut Aquifer Protection Act and local aquifer protection regulations.11

Spill Prevention and Control Plan: A document prepared by a regulated entity that outlines measures to prevent, contain, and respond to spills or releases of hazardous materials within an Aquifer Protection Area.12

Stormwater Management: Practices and structures designed to reduce the volume and improve the quality of stormwater runoff from a site, particularly in areas where runoff may carry pollutants into groundwater or surface water resources.13

Stratified Drift Aquifer: A geologic formation composed of layers of sand and gravel deposited by glacial meltwater, which can store and transmit significant quantities of groundwater.14

Underground Storage Tank (UST): A tank and any underground piping connected to the tank that has at least 10 percent of its combined volume underground, used to store petroleum products or hazardous substances.15


  1. Connecticut General Statutes, Section 22a-354a(1)

  2. Connecticut Regulations of State Agencies, Section 22a-354i-9(a)

  3. Connecticut General Statutes, Section 22a-354c

  4. Connecticut General Statutes, Section 22a-354a(8)

  5. Connecticut General Statutes, Section 22a-354a(6)

  6. 40 CFR 261.3

  7. Connecticut General Statutes, Section 22a-354i(g)

  8. Connecticut General Statutes, Section 22a-354a(15)

  9. Connecticut Regulations of State Agencies, Section 22a-354i-3

  10. Connecticut General Statutes, Section 22a-354a(17)

  11. Connecticut General Statutes, Section 22a-354a(18)

  12. Connecticut Regulations of State Agencies, Section 22a-354i-9(d)

  13. Connecticut Stormwater Quality Manual, Chapter 1.1

  14. Connecticut General Statutes, Section 22a-354a(20)

  15. 40 CFR 280.12

Keep up with the latest

A Note to Our Readers: We hope this guide is a valuable resource in helping you better understand the . However, it's not a substitute for professional advice and doesn't cover every scenario. Always consult with regulatory bodies and professionals for the most current advice and project-specific guidance.