Maine’s Environment 1994

Maine Lakes and Rivers

Maine has more than 31,600 miles of rivers and streams and over 5,785 lakes and ponds covering 1,762 square miles. Maine's waters have been classified using a rating system from the Clean Water Act tied to whether people can fish or swim in them. Overall, 98.7% of Maine riverine waters attain the interim goals of the Clean Water Act, while only 78% of the length of Maine's 19 major rivers are in attainment. Maine lakes are all fishable and swimmable although 24.4% only partially support these uses and 5.3% are threatened. Over 90% of Maine's marine and estuarine waters meet the fishable goals of the Clean Water Act. The primary reason these goals are not met in major rivers is priority pollutants, most notably dioxin. Organic loading from nonpoint source pollution and bacteria from municipal waste water treatment plants, on-site wastewater treatment and untreated discharges also contribute. The inability to swim or fish in Maine's lakes and ponds is largely attributed to organic loading caused by run-off from development, agriculture and silviculture.

Fish Consumption Advisories

Toxic substances such as dioxin and heavy metals persist in the environment and accumulate in fish. Dioxin is an unwanted by-product of the chlorine bleaching process utilized by many Maine paper mills. Paralleling increased efforts to reduce dioxin levels in mill discharges, fish tissue analyses have shown a general decline in dioxin concentrations since 1990, although levels have stabilized since then. In 1994, tomalley from Maine lobsters showed the presence of dioxin.

Also in 1994, advisories were issued for freshwater fish because of elevated levels of mercury. Although Maine has several known sources of mercury emissions, it is believed that most of what is deposited originates in states to our south and west. The extent of our mercury problem is not known, but it is likely that both in-state and regional solutions must be sought Thirty-four other states in the U.S. have a similar advisory for mercury.

Ground Water

Over 50% of the state's population gets their drinking water from ground water. Nearly all ground water contamination in Maine originates from non-point source pollution rather than point source pollution. Leaking underground oil storage tanks are considered the largest threat to ground water quality from point sources. Underground storage tanks have been regulated since 1985 and must be upgraded and replaced in a phased schedule depending on their age and proximity to drinking water supplies. Almost 28,000 underground oil storage tanks have been removed since 1986. There are approximately 8,129 old tanks in Maine that still need to be removed.

Sewage Treatment

Forty-five percent of Maine's population is served by community sewage treatment facilities. However thirty-nine Maine towns and cities have stormwater collection systems that are linked with their sewage systems, creating combined sewer overflows (CSOs). During spring as well as summer rain storms, the capacity of sewers is exceeded and untreated wastes can be discharged into Maine's surface waters. Efforts are underway to address CSO problems state-wide.

Wastewater from our homes also affects Maine's resources. For example, malfunctioning subsurface disposal systems, direct outfall pipes and overboard discharges are responsible for closing 25% of Maine's productive mussel and clam flats. There are 2,407 licensed overboard discharge systems along Maine's coast despite the prohibition of new systems and a requirement for replacement where possible. The State is targeting overboard discharge replacement adjacent to redeemable shellfish flats and has helped fund the removal of 135 systems to date, with bond monies.

Challenges for the Future

The need for cleanup and pollution prevention continues. The focus has shifted to dioxin discharged from Kraft pulp and paper mills, organic loading from non-point source pollution and bacteria from municipal sewage treatment plants, on-site wastewater treatment or untreated discharges. Old wastewater treatment plants need upgrades and replacement, while new or different production processes to reduce pollution need to be explored.

Toxic contamination of our surface waters is an increasing threat. The Maine Department of Environmental Protection is monitoring toxics in lakes and marine waters. We should soon have a better picture of the nature, extent and fate of toxics in Maine’s surface waters.

Relicensing of Maine’s existing hydropower dams by the Federal Energy Regulatory Commission offers the first-ever opportunity for Maine to achieve a balance among competing river uses. These used include public recreation, fish and wildlife habitat and hydropower generation.