Chemical pollutants from contaminated sites often migrate to surrounding areas, making their way through the soil, sub surface utilities and into the groundwater causing groundwater contamination. This migration of contamination into groundwater results in the groundwater being unsuitable for use and may also adversely affect the quality of surface water and sediments. Contaminated groundwater may also affect the types of land uses that may safely be carried out above a contaminant plume.
The legacy of groundwater contamination can be a major burden on the community because once groundwater is contaminated it is generally difficult and costly to remediate. Therefore, preventing groundwater contamination is the most practical way of protecting groundwater quality. Where contamination of groundwater is identified, acute risks, such as the possible accumulation of explosive vapours in subsurface utilities, must be immediately managed. The source of contamination and the area of gross contamination should be removed to ensure the protection of human health and the environment.
Sources of groundwater contamination
One of the major sources of groundwater contamination are underground storage tanks (USTs) containing fuel, oil, chemicals, or other types of liquids. Over time these tanks and their associated lines and dispensing bowsers will inevitably corrode, crack and develop leaks, so they’re best addressed sooner rather than later.
Groundwater contamination prevention
The Protection of the Environment Operations (Underground Petroleum Storage Systems) Regulation 2008, aims to prevent soil and groundwater contamination by insisting that groundwater monitoring wells are installed to all underground fuel tanks and systems. Wells must be compliant with NSW EPA guidelines, designed by qualified personnel, clearly marked and secured, and sealed to exclude surface water. Groundwater monitoring wells must also be tested every six months, if it’s suspected that the groundwater is contaminated by petroleum, or if loss monitoring procedures indicate that loss has occurred from the system.