Before construction of a new public water source is initiated, proposed plans must be submitted to the DWP for approval. (22 M.R.S. §2612)

Step 1: Preliminary Approval

Before a new well is drilled, the selected site must be approved by the Drinking Water Program. The State of Maine Rules Relating to Drinking Water establishes a set-back for all wells of at least 300 feet from any potential sources of contamination (such as fuel tanks and leach fields). If site conditions so require, a waiver of this setback requirement may be requested.

Per- and polyfluoroalkyl substances (PFAS) are human-made chemicals that have been widely used since the 1940s in consumer products and industrial applications. Due to their widespread use and persistence in the environment, most people in the United States have been exposed to some level of PFAS. There is evidence to suggest that continued exposure above specific levels to certain PFAS may lead to adverse health effects.

The Lead and Copper Rule Revisions (LCRR) represent the first major update to the Lead and Copper Rule (LCR) in nearly 30 years. “EPA’s new rule strengthens every aspect of the LCR to better protect children and communities from the risks of lead exposure. The new LCR will better protect children at elementary schools and childcare facilities, get the lead out of our nation’s drinking water, and empower communities through information.” – US Environmental Protection Agency

Disinfection by-products (DBPs), also called trihalomethanes, are formed when chlorine and bromine interact with natural organic materials in water, such as in chlorinated drinking water. To protect drinking water from disease-causing organisms, or pathogens, water suppliers often add a disinfectant, such as chlorine, to drinking water. However, disinfection practices can be complicated because certain microbial pathogens are highly resistant to traditional disinfection practices.

The Surface Water Treatment Rule (SWTR) seeks to prevent waterborne diseases caused by viruses, Legionella, and Giardia lamblia. These disease-causing microbes are present at varying concentrations in most surface waters. The rule requires that water systems filter and disinfect water from surface water sources to reduce the occurrence of unsafe levels of these microbes.

If a public water system uses a lake, river, stream or pond as its water source, then it is regulated by the Surface Water Treatment Rule.

A radionuclide is an atom with an unstable nucleus which, to become more stable, emits energy in the form of rays or high-speed particles. This is called ionizing radiation because it can create "ions" by displacing electrons in the body (e.g., in the DNA), disrupting its function. The three major types of ionizing radiation are: alpha particles, beta particles and gamma rays.

Nitrates and nitrites are nitrogen-oxygen chemical units that combine with various organic and inorganic compounds. They come from the breakdown of nitrogen compounds in the soil, where flowing ground water picks them up. High levels of nitrates and nitrites in groundwater are usually due to human activities but can sometimes be found naturally in groundwater. The major sources of nitrates and nitrites in drinking water are runoff from fertilizer use, sewage – especially leakage from septic tanks – and erosion of natural deposits.

Groundwater Rule

Summary

The intent of the Groundwater Rule (GWR) is to provide for increased protection against microbial pathogens in public water systems that use ground water sources. The GWR was written with particular concern about those ground water systems that are susceptible to fecal contamination since disease-causing pathogens may be found in fecal contamination.

Rules, Policies, and Regulated Contaminants

The Drinking Water Program is the primacy agency responsible for enforcing the federal Safe Drinking Water Act along with Maine drinking water laws and regulations.