Groundwater is one of the nation’s most important natural resources. However, due to a combination of different human activities the quality of this water can be placed at risk, potentially rendering it unsuitable for use. Groundwater contamination is the result of either point source leakage or diffuse sources. Examples of point source contaminants include leaking underground storage tanks, ill-managed waste disposal sites and inadvertent chemical spills. On the other hand, diffuse source contamination is generally the result of pesticides and nutrients that infiltrate agricultural land and leach down through the soil to the water table. Once groundwater is contaminated, remediation can be a slow and costly process. Consequently, ensuring good practice is the best way of protecting groundwater quality.
Water Quality Assessments
There are two main types of water quality assessment that ADE conducts:
1. Groundwater Quality Assessment
- Provision of a cost effective system design
- Monitoring well installation and maintenance,
- Includes aquifer analyses and characterisation.
- Identifies the likely location/direction of any existing or potentially contaminated groundwater plume flow;
- Assesses and describes the source, type, extent and level of contamination (if present);
- Provides an assessment of groundwater contamination in regards to the USTs.
2. Water Supply Investigations
- Sampling is undertaken in accordance with NSW EPA guidelines, NEPM Amendment, 2013 for potential contaminants.
- Typical water quality parameters monitored by ADE are:
- Dissolved oxygen
- Electrical conductivity (EC)
- Biological oxygen demand (BOD)
- Heavy metals
- Poly-aromatic hydrocarbons (PAHs)
- Total Recoverable Hydrocarbons (TRH)
- Benzene, Toluene, Ethylbenzene and Xylene (BTEX)
- Faecal Coliforms
- Analysis of samples by a NATA accredited laboratory.
All water quality assessments comply with the following guidelines:
- Guidelines for Implementing the Protection of the Environment Operations (Underground Petroleum Storage Systems) Regulation 2008, NSW DECCW 2009.
- Guidelines for the Assessment and Management of Groundwater Contamination, NSW DEC, 2007.
- Guidelines for Consultants Reporting on Contaminated Sites, NSW EPA, 2000.
- Sampling Design Guidelines – NSW EPA, 1995.
- Guidelines for the NSW Site Auditor Scheme, NSW DEC 2006.
- Guidelines on the Investigation Levels for Soil and Groundwater, National Environmental Protection Measure (NEPM) 2013.