Articles
The State of Florida's Experiences with Thermoplastic Flexible Piping By Marshall T. Mott-Smith, Administrator, Storage Tank Regulation Section Bureau of Petroleum Storage Systems Florida Department of Environmental Protection Editorial Comment The APEA, in this issue of The Bulletin, is sharing some disturbing news from the USA, Marshall MottSmith a regulator from Florida has produced an extensive insight into some of the problems experienced with flexible pipe work. This flexible pipe work is not new to Europe where the more common pipe work installations are the more rigid polyethylene systems. However, where these flexible systems have been used we are not aware of similar problems in Europe, perhaps there are some difference is use (exclusively pressure in US) or poor contractor installation as suggested by the manufacturers, which has caused these concerns. Introduction There are two types of thermoplastic pipes, semi rigid and flexible. One type of thermoplastic piping could be best characterised as “semi-rigid”. These are constructed with high-density polyethylene and the joints are electro-fusion welded. These semi-rigid pipes are not involved in the analysis and investigation of this paper. There are two manufacturers approved for use of semi-regid piping in Florida (UPP and NUPI) one has been in use for four years, and no incidents have been reported to Department of Environmental Protections (DEP) to date. Incidents and discharges involving thermoplastic flexible piping (flexpipe, for brevity's sake) connected to underground petroleum storage tanks have recently become more numerous, particularly in the southeastern United States. This problem has become a significant issue for a number of interests. Facility owners are angry because their relatively new flexpipe systems are failing within five years of installation. Piping installers are frustrated with having to perform
frequent site visits to respond to the incidents and repair the systems. Piping manufacturers insist that faulty installation or inadequate operation and maintenance caused the problems. Regulators are caught in the middle. However, it is the regulators that must deal with the facility's non-compliance and the cleanup of petroleumcontaminated soils and groundwater. Unlike rigid fiberglass reinforced plastic and steel piping systems, which have been in use for many years, flexpipe is a relatively new technology and its limitations are not widely known. The purpose of this article is to provide information regarding those limitations and dispel the myth that flexpipe is a "bury it and forget it" system. Due to the large numbers of thermoplastic flexible piping systems being installed, the Department of Environmental Protection (DEP) wants installers, owners, and operators of such systems to become educated about the problems associated with flexpipe and encourage better installation, monitoring and maintenance of these systems. Background Information In Florida, the regulation of underground and aboveground storage tank systems is the responsibility of the DEP's Bureau of Petroleum Storage Systems. Florida began its regulatory efforts in the early 1980s after a leaking underground storage tank contaminated the city of Belleview's drinking water supply well. In 1983, the Florida Legislature responded by passing laws that enabled the DEP to adopt rules for aboveground storage tanks (ASTs) and underground storage tanks (USTs). Florida's rules initially only required that tanks and piping be protected from corrosion or be constructed with corrosion-resistant materials. In 1990 and 1992, the rules were
amended to require secondary containment for new tanks and piping. The rules also established deadlines for existing storage tank systems to upgrade to secondary containment by deadlines established in the rules based on the age of the storage tank system. The first deadline was 1989, and the last deadline will be December 31, 2009. Facility owners upgrading their tanks and piping to meet the 1989 and 1992 deadlines typically chose double-wall fiberglass pipe. In Florida, this piping was usually manufactured or sold by Ameron or Smith Fiberglass. Flexpipe was just emerging as an option in the early 1990s, and was not commonly available for the 1992 deadline. Before any piping integral to a storage tank system is installed in Florida, the piping must be third party certified by a nationally recognized laboratory as meeting the DEP's standards, or it must be approved and listed by Underwriter's Laboratories (UL) and subsequently approved by the DEP. The Florida DEP first allowed flexpipe as "approved equipment" in 1995. Total Containment, Inc. (TCI) manufactured that piping. As with TCI's piping, other manufacturer's equipment (Bufflex, Environ, APT, Western Fiberglass, OPW, UPP, and NUPI) obtained approval as it came on the market. Many owners chose flexpipe to meet Florida's 1995 deadline (for tanks and piping installed between 1976 and 1980), as well as in 1998 (for tanks installed between 1980 and 1984). Florida's Storage Tank Program contracts with county-level governments to implement a legislatively mandated effort called the "Compliance Verification Program". The contracted-counties perform routine compliance, installation, closure, and discharge inspections of all storage tank facilities within the state, with a goal of inspecting every facility once a 47
