AUGUSTA — Beginning next year, septic inspections will be required prior to the sale of lakefront homes and camps throughout Maine under a bill signed into law this week.

Since 2007, homebuyers have been required to obtain septic system inspections prior to purchasing properties located within the “coastal shoreland zone,” which extends 250 feet from the normal high-water line. A bill passed by the Legislature and signed by Gov. Janet Mills on Monday would expand that septic inspection requirement to home sales within any shoreland zone – including lakes, great ponds and rivers.

Supporters said the inspections will have the twofold benefit of detecting malfunctioning septic systems that leach pollutants into adjacent waterbodies while ensuring homebuyers are aware of potentially costly repairs before a sale is finalized. A homebuyer would have one year to repair or replace a malfunctioning septic system.

Supporters of the expansion included the Maine Municipal Association, organizations representing water and sewer districts, Maine Audubon, the Natural Resources Council of Maine, Maine Lakes Society, and numerous local or regional lake associations.

“This new law will strengthen the safety net for Maine lakes, which face continued pressures from many different sources of pollution runoff, including failing underground septic systems,” Pete Didisheim, advocacy director at NRCM, said in a statement. “We’re especially pleased that this law will help protect Sebago Lake, which serves as the water supply for 200,000 Mainers. With 4,000 lots within 200 feet of the lake, containing about 2,700 septic systems, this new law will help protect public health and clean water.”

The Maine Department of Environmental Protection and the Maine Department of Health and Human Services also supported the bill, L.D. 216.

The Maine Association of Realtors opposed the mandate, arguing that most real estate professionals already provide a wealth of information aimed at ensuring buyers fully educate themselves about the property – including the septic system – before completing a purchase.

Pollution from malfunctioning or ineffective septic systems can contribute to nutrient overloads in adjacent waters. When combined with runoff from fertilized lawns as well as roads, septic pollution can contribute to algae blooms, fish kills or other water quality concerns in lakes and ponds.

Under the new law, which takes effect Jan. 1, homebuyers would have nine months to complete an inspection if one was not feasible prior to purchase. Additionally, inspections would not be required if a septic system was installed within the previous three years or if the homeowner could provide a written copy of an inspection conducted during the previous three years.

The Legislature passed a similar bill in 2017, but the measure was vetoed by Republican Gov. Paul LePage.