Until approximately five years ago, the accepted method of hydrant system leak detection on airport hydrant systems was perpetual inventory management and nightly hydrostatic tests of the piping system by observing pressure changes in the system during periods of non-operation. Until recently the accuracy of these leak detection methods had not been defined, nor was it scrutinized by regulatory authorities.
Since that time, state regulatory authorities have focused on airport hydrant system leak detection resulting in past methods of leak detection (perpetual inventory management and nighttime hydrostatic leak testing) not having the inherent accuracy required to prevent environmental problems related to hydrant line leak detection. California and Virginia recently promulgated regulations requiring that airport hydrant lines be tested with a leak detection accuracy of 3 to 5 gph.
Several airports have undergone the design, permitting, and construction of a centralized bulk storage facility for the entire airport and required tenants to remove their old fuel systems. Others are in the planning or evaluation phase on how best to deal with the old fuel system (e.g. upgrade or replace).
One issue is when and how to test the hydrant system and, if found to be leaking, how to approach the situation (e.g. abandon the line, replace with new, or repair). Most of the older hydrant lines, hydrant pits, and transfer lines were not installed with a leak detection system, or had secondary containment (double-wall pipe) or corrosion protection.
A Need for Internal Documentation
Most airport fuel systems are reaching 20 and 30 years of services or more and are starting to show signs of deterioration. Once the old system is tagged with abandonment, the next issue is how to handle the environmental impact. Although environmental-related projects are not cheap, the government is allowing the approach to soil and groundwater clean-up to be evaluated on level of risk to the environment and surrounding receptors (populations, schools, water supply wells, etc.) versus cleaning up every drop of fuel at an airport.
Many airports and tenants have constructed new fuel systems to replace the old. Although not required by the regulations, owners and operators of new fuel systems should consider creating a document which describes the system in detail and the operation and maintenance procedures of the system.
Some of the newer systems include equipment that is unfamiliar to most (e.g., automatic leak detection for hydrant lines) and the manufacturer's manual may be difficult to interpret. Creating a manual which describes how to operate the system from top to bottom and procedures to follow in the event something goes wrong would minimize risk associated with operating the farm and maximize the operation of the facility.
Over the past five to ten years, tenants and airports alike have identified their issues and liabilities and, in most cases, either fixed the problem or have plans in place to do so. The environmental program for most has become one of maintaining versus reacting which is a result of the UST compliance deadline and general awareness of the regulations which apply to airports.