By the calendar, it’s still officially summer, but recent dips in the temperature have given us a reminder — as if we need it — that winter isn’t all that far away.

Every Mainer knows they aren’t ready for colder weather unless their source of home heat is secure. And Maine homeowners’ widespread reliance on oil means that more than once per day, heating oil has leaked or spilled in somebody’s basement or backyard, posing environmental risks and requiring costly cleanup.

A tank replacement program was implemented 15 years ago, but many Mainers still have old, single-wall tanks that are prone to spills. Tank requirements haven’t kept up with technology that allows tanks to contain spills.

State policymakers need to step into this gap, encourage upgraded tanks and fund incentives for compliance. There’s no reason for Mainers to choose between warm homes and a clean environment when they can — and should — have both.

We’re more aware of oil spills caused by railroad and pipeline accidents than we are of household heating oil spills, but the latter literally hit much closer to home. In Maine, half of all homes depend on wells for drinking water, so heating oil or kerosene spills could have widespread impacts.

The price tag is steep, too: Last year, the Maine Department of Environmental Protection spent $1.2 million to clean up contaminated groundwater sites. (The DEP couldn’t calculate how much groundwater pollution is attributable to home heating oil spills versus other sources.)

Seventy percent of Maine homes still rely on oil for some heat, but nobody knows how many of those homes are at risk of a leak or a spill. After an oil tank is installed, no state law requires it to be inspected or monitored. There’s also been no move to require that Mainers use the new double-wall tanks, which help prevent water pollution by holding any oil leaked from the inner container. These are the tanks the DEP installs as part of its replacement program.

Of course, those who aren’t eligible for the state tank-replacement program may be reluctant to foot the bill for a new tank if they don’t see the payoff right away. It’s hard enough for many Mainers to fill the tank, much less buy a new one. The DEP could give homeowners a positive incentive in the form of rebates for people who upgrade their tanks, just as Efficiency Maine subsidized the purchase of power-saving appliances.

The state money should be spent on incentives for new tanks, not paying for cleanups caused by old ones.

Maine also has the opportunity to break ground on environmental policy. Double-wall oil tanks aren’t yet industry standard, but that could change if state policymakers decide to tighten state law. Neighboring New Hampshire prods homeowners to make their tanks safer by reducing the state’s share of funding for the cleanup of spills from outdated oil tanks.

A significant share of Mainers’ monthly budgets goes toward staying warm during our long, cold winters. If tank upgrading can be made more affordable, that would ensure conservation of home heating oil and the preservation of a clean water supply, a win for everyone.