Coast & Estuaries
Page 202
conditions is that Penrice develop and maintain an Environmental
Improvement Program (EIP) regarding ammonia loss to the marine outfall.
This aim aligns with the water quality Environmental Protection Policy, the
Adelaide Coastal Water Study, and Port Waterways Quality Improvement
Plan’s aim to reduce the nutrient loading to the marine environments from all
sources.
Penrice have met the requirements of this progressive reduction and are on
track to achieve the targets set. (Penrice, 2010).
The implementation of the ammonia reduction Environment Improvement
Program at Penrice Soda Products has resulted in a 30% reduction in the
discharge of ammonia to the River since 2005 (Penrice, 2010).
Penrice also aims to further reduce its discharge to 250 t/year of Nitrogen by
2015. Although no relevant cost-effective technology is presently available,
research and development over the next five years will be aimed at
developing ways to achieve the required discharge reduction. Penrice will
pursue nutrient load reductions under EPA licensing arrangements until
agreed sustainable loads are achieved (EPA WQIP, 2008).
A small fraction of the total ammonia present in the water column will be
present in the ionised form (NH4), and in this form can have toxic effects on
marine organisms such as fish, invertebrates, algae and plants.
The above figure 52 shows the extent of ammonia pollution within the Port
Adelaide River, with sites 1,2,4,5,6,7 and 9 classified by the EPA as ‘poor’. -
exceeding the 90
th
percentile of Australian and New Zealand Environment
Conservation Council (ANZEC) trigger values for potential toxicity. Site 3
was rated as ‘moderate’. Sites 1 and 9, located within the Port Adelaide
River, had significantly higher concentrations than other locations in 2007,
however the trend of ammonia concentration appears to be reducing since
monitoring started in 1998 (EPA, 2011). The level of ammonia within the
Port Adelaide River is still
very high for a marine or estuarine system and
there are still numerous ecosystem impacts from these high nutrient levels
throughout the Port River & Barker Inlet.
Heavy metals
Heavy metals such as copper have been observed at concentrations above
guideline values in the Port River and along the metropolitan coast. The EPA is
conducting a study of heavy metal bioaccumulation in the Port waterways – that
is, how much of the contaminants are being accumulated in the systems of
marine animals which filter the water as part of their feeding processes. The
study is using the Blue mussel (
Mytilus galloprovincialis
) in plastic cages
scattered across locations for approximately two months. The amount of heavy
metals that accumulate in the mussels will be compared to other mussels that
are being monitored for the same period at South Australian locations that are
not contaminated. The results of this study will help assess the ecological risk of
