MAINE DEPARTMENT OF ENVIRONMENTAL PROTECTION THE MORE YOU KNOW, THE MORE YOU SAVE – AST SPILL PREVENTION

Roughly 400,000 above ground home heating oil storage tanks are currently in use in Maine. Every day, the Maine Department of Environmental Protection (DEP) responds to approximately 1.5 spills from home heating oil tanks across the state. These spills range in severity; from just a few gallons requiring a simple clean up, to hundreds of gallons requiring extensive excavation and engineering systems to mitigate health and environmental hazards due to contaminated soil, drinking water, and indoor air. To the unsuspecting fuel customer, these spills can be overwhelming, often leading to many questions about potential costs, property damage, liabilities, and health risks. In those stressful moments, the last thing a fuel customer wants to hear is that the spill was most likely entirely preventable!

Most spills fall under one of three main categories: tank corrosion, parts failure, or human error. Tank corrosion is the most common of the three main culprits. Corrosion slowly eats away at the steel, compromising the integrity of a tank and allowing leaks to occur. Parts failures can occur due to old age, damage obtained during weather events, or tipped tanks due to unstable bases or rusted tank legs. Causes of human error include overfilling, improper maintenance (or no maintenance at all), and stepping on or bumping into unprotected lines or parts.

With the proper knowledge and preparation, spills can be prevented. Parts failure and human errors can be prevented by performing periodic visual inspections of tanks and supporting equipment before they fail. Visual inspections can be done by a professional or homeowners who know what to look for. To assist homeowners in inspecting their tank, the DEP has developed a “Check Your Tank” checklist that is available online. Tank corrosion is less easily identified and causes nearly 50% of spills. Tank corrosion often occurs from the inside out, making it easier for it to go undetected. However, ultrasonic thickness testing is one way to check for corrosion in tanks under 20 years old. For tanks older than 20 years, ultrasonic thickness testing is less reliable and instead fuel customers should start to consider replacing their tank as it nears the end of its design life of 25 years. In these situations, DEP recommends double wall or double bottom tanks that minimize risk of a spill due to tank corrosion and has leak detection capabilities in the event of a leak.

The more you know, the m

A spill can impact a fuel customer and their home in several ways. A leak or spill often results in contaminated soil, which can be harmful to those who come in contact with it. Contaminated soil can also lead to contaminated groundwater, a major concern for drinking water if there are private wells or public drinking water supplies in the vicinity. Indoor air quality becomes a concern in the event of a spill, as contaminated soil beneath a home or contaminated material within a home can allow vapors to become concentrated indoors, posing a respiratory hazard. Homeowners will need to work with DEP staff to schedule site visits and allow DEP access to their property for monitoring until remediation work is concluded. Even with intervention, the effects of a spill may subside in a few months or may persist for several years.

All spills, big or small, are a common problem throughout Maine. The impacts of a spill have the potential to affect the fuel customer, the fuel provider, the environment, neighbors, and beyond. Whether the cause is tank corrosion, parts failure, or human error there are ways to prevent these spills from occurring. Spreading awareness of this issue, doing regular tank inspections, and taking preventative actions are just a few examples of how we can work together to address this pervasive issue.

Contact Racheal French at Maine DEP for ideas to protect homeowners from a home heating oil spill; she can be reached at Racheal.French@maine.gov or 207-481-6860.

With the proper knowledge prevented by performing periodic inspections can be done by in inspecting their tank, the