Underground storage tanks are increasingly becoming essential components of building projects, driven by rising interest in on-site rainwater and graywater collection and reuse. As a result, building officials may need to expand their expertise to include these products and their components. Some safety inspection work is obvious; for instance, checking that the installer or project owner obtained all necessary permits for the tank installation. Some elements of an inspection, however, are not as intuitive. Therefore, it is important for inspectors to educate themselves.
In the past, the area of focus for tanks was corrosion- resistance. Over the last 50 years, federal regulatory agencies and corporations have gained considerable knowledge about how to protect the environment when it comes to underground storage vessels. In the 1960s, companies began to find that steel underground petroleum tanks buried decades earlier were leaking their contents into the groundwater as these predominantly steel tanks corroded. Since that time, federal and state agencies, as well as independent organizations, have developed numerous regulations and codes to ensure that underground vessels can be operated in a manner that is safe for the environment.
The result was that research and development in the tank industry focused on improving the materials and technology used in tanks. It was clear that underground tanks used for storing or processing liquids needed to be durable, offering long-lasting corrosion- resistance. Such materials as fiberglass, which is inherently corrosion-resistant and does not require a protective lining or coating, have since become an increasingly popular tank choice for a variety of underground storage applications.
More recently, interest in sustainability has created an overall movement in the United States for citizens, governments, organizations and corporations to act responsibly in matters of environmental protection and conservation. Average citizens are becoming more aware of environmental concerns, particularly in regard to available fresh water supplies. With a growing population base on the one hand and a dwindling fresh water supply on the other, people are realizing that on-site water collection and reuse is an essential part of both conserving and preserving water supplies. In addition, green building programs like the U.S. Green Building Council’s LEED program and the International Green Construction Code (IGCC) have promoted water efficiency and encouraged builders and developers to incorporate stormwater management, water-efficient landscaping, water use reduction and innovative wastewater technologies into their projects.
A major responsibility of inspectors is to verify that the tank being installed has been manufactured to meet all applicable requirements, such as those in standards by Underwriters Laboratories® (UL), the American Water Works Association (AWWA) and NSF International for the intended application. For some non-potable water applications, however, there are no current standards for certain tank types. Generally, the tank itself and any accessories or piping must be made of corrosion-resistant materials approved for the particular application. In the cases of graywater and wastewater tanks, the materials used must also be compatible with the treatment system used with the tank.