Wingham Sewage Treatment Plant

Environment Protection Licence #1581
Wingham Sewage Treatment Plant treats on average 1.2 million litres of sewage daily. It is an extended aeration plant utilising biological processes followed by ultraviolet disinfection. Approximately 50% of the treated effluent is beneficially re-used for farm irrigation at Wingham Bight with remaining effluent discharged to the Manning River.

 

A requirement of the Wingham sewage treatment plant Environment Protection Licence (# 1581) is to meet concentration limits for specific water quality parameters from treated effluent discharged into the Manning River. The Wingham licence has a range of concentration limits listed including 50 percentile, 90 percentile and 100 percentile limits. These limits relate to the monitoring of results throughout the licence period.

 

To meet a 90 percentile limit, the monitoring results must not exceed the specified concentration limit for 90% of the time during the monitoring period. Likewise, 50 percentile concentration limits are to be achieved for 50% of the results throughout the monitoring period. The 100 percentile limits are not to be exceeded, alternatively the maximum concentration.

 

The Wingham licence monitoring period is reported upon annually with an anniversary date of the 1stof March. As a condition of the licence the treated effluent is monitored monthly, discharge concentration limits are specified for the Biological Oxygen Demand (BOD), Total Suspended Solids (TSS), Ammonia and ph. The corresponding concentration limits specified in the licence for each of these parameters are listed in Table 1. The licence also stipulates fortnightly monitoring of the treated effluent for faecal coliforms. There is no specific concentration limit requirement for faecal coliforms.

 

Table1.Wingham licence effluent concentration limits for Biological Oxygen Demand, Total Suspended Solids, Ammonia and pH

 

Wingham STP
EPA I.D point No 1.
Discharge to waters
BOD
TSS
Ammonia
pH
mg/L
mg/L
mg/L
pH units
50%ile
Limit
20
20
90%ile
Limit
30
30
100%ile
Limit
35
35
10
6.5-8.5

 

EPA Licence

Wingham Effluent Results EPA id point No 3