Wellfield Protection

The Wellfield Protection Ordinance No. 84-60 controls the non-residential storage, handling, use, or production of toxic substances (Regulated Substances) within specific areas around drinking water wells. These specific areas, called Zones of Influence, are determined by theoretical, pollutant time-travel contours based on soil conditions, well pumpage rates and surface water boundaries.

Zone 1 - None of the regulated substances may be stored, handled, used, or produced within this zone, the outer boundary of which is the 10-day travel time contour.

Zone 2 - All regulated substances must be contained in a manner which will prevent entry of any spills to the aquifer. In addition, the substances must be inventoried and secondary containment provided. Finally, monitoring wells placed to detect the presence of regulated substances moving toward the drinking water well must be constructed and periodically sampled. 10-day to 30-day time contour.

Zone 3 - Activities involving regulated substances must be permitted and the substances periodically inventoried to detect any spills. If a spill occurs, the activitiy must install the containment required for Zone 2. 30-day to 210-day time contour.

zone diagram

Potential Areas of Pollution

Household Regulated Substance Checklist -- Do you Use Any of These?

Gasoline ¦ Oils ¦ Diesel Fuel ¦ Solvents ¦ Cleaning Fluids Detergents ¦ Paints ¦ Thinners/Strippers ¦ Fertilizers Pesticides
Herbicides ¦ Lead Acid Batteries
Brake Fluid Transmission Fluid

If you have any of these items, then you may have an effect on the quality of your drinking water, based on chemical application or use procedures, and your location within the wellfield zone of influence.

Steps the Individual Can Take to Ensure Groundwater Protection

  • Determine your location within the wellfield zone in relation to drinking water wells and wellfield zones.
  • Never dump any hazardous materials onto open terrain or outside ground.
  • If you have a septic tank, never pour any hazardous material down the drain.
  • When gardening, take care to purchase products which are known to be environmentally safe.
  • Educate yourself on how to properly store, handle, and utilize hazardous materials, to prevent their release into the environment in a manner that could potentially contaminate our water supply.

For more information or assistance, contact the Department of Planning & Environmental Protection Staff