• The treatment plant has been designed to treat 4.32 ML/day.

• In 2010 average dry weather flow was about 2.3 ML/day.

Hastings Point Wastewater Treatment Plant is located on the Round Mountain Road west of the village. The treatment plant serves Bogangar/Cabarita, Hastings Point and Pottsville which are sewered with conventional gravity systems and pump stations.

Features of the Plant include:

• The treatment process is an activated sludge process with chemically assisted phosphus removal.

• The inlet works comprise a main channel fitted with a mechanical step screen, screening conveyor and bagging unit, storm overflow chamber and by-pass channel, two grit arrestors and classifier and a flow divider to split the flows downstream of the inlet works into two.

• Two intermittently decanting extended aeration tanks, each with a design capacity of 9000 equivalent persons.

• Two lined in-ground balance ponds.

• Tertiary Filtration of the clarified effluent is carried out via a Disk Type cloth filter and disinfection with Chlorine.

• Storm lagoon storage and pump station.

• Chemical dosing facilities for Alum (Aluminium Sulphate) and Chlorine (Sodium Hypochlorite) and bunded storage area.

• Deodorisation bed and blower to extract foul air from Inlet works.

• Effluent Pumping Station.

• Two sludge lagoons and two sludge drying beds.

Grit Chamber	Extended Aeration Tank

Discharge of Treated Effluent in Sand Dunes

Treated Effluent is discharged to exfiltration trenches in the beach dunes east of the plant.

There were originally 4 arms in the exfiltration trenches, each 100m long, and this was recently upgraded to double the number of arms to 8. Council cycles the effluent discharge between the different arms and piezometers are installed around the trenches to monitor groundwater levels and water quality.

The dunes system requires fortnightly cleaning using Sodium Hypochlorite to maintain the efficiency and performance of the system.

Sand dunes exfiltration system	Balance Pond in foreground

 

The EPA licence limits (3618) are listed on the following table for all flows up to three times the average dry weather flow.

Parameter	Units	90th Percentile Concentration	100th Percentile Concentration
Requirements for environmental discharge (to Rous River)
Biological Oxygen Demand	mg/L	10	20
Non Filterable Residues 9Total Suspended Solids)	mg/L	15	30
Total Nitrogen	mg/L as N	10	20
Total Phosphorous	mg/L as P	1.0	2.0
Oil & Grease	mg/L	5	10
pH	-	Range 6.5 to 8.5