Licence conditions for pollution studies and reduction program


  

Licence conditions for pollution studies and reduction programs

Summary
 
Licence number: 1397
Title: Sewage Treatment Plant Process Optimisation - Short Term
Start date: 23 Jun 2014
 
Licence Condition
1) By 31 December 2016 the licensee must submit the detailed design for all works outlined below in conditions 1.2, 1.3 and 1.4 and implement Option E and Option X in the document “Batemans Bay STP - Discussion Paper on Treatment Process Optimisation” (NSW Public Works, 2014) and other agreed works as outlined in Conditions U1.2, U1.3 and U1.4 below and, 2) By 30 June 2017 the Licensee must commission all works to implement Option E and Option X in the document “Batemans Bay STP - Discussion Paper on Treatment Process Optimisation” (NSW Public Works, 2014) and other agreed works as outlined in Conditions U1.2, U1.3 and U1.4 below.
Install recommended option E works to ensure that all flows up to 160L/s receive tertiary filtration, and including the following works: 1)   Install separate backwash water storage and associated dedicated clean backwash water pumping facilities;   2)   Backwash facilities sized with a minimum backwashing capacity of an entire bank of three filters at one time; 3)   Filtration facilities will be capable of providing tertiary treatment of effluent flows up to 160L/s; 4)   Storage facilities to ensure that backwash waste water is captured and not diverted to the storm detention pond and not directed through the secondary treatment again (additional to options E and X); 5) Utilise a dedicated backwash tank in lieu of discharging backwash into the storm detention pond.
Install a ultraviolet disinfection system that achieves the following criteria: 1)   All flows up to 227L/s to receive full disinfection (90th percentile performance criteria faecal coliforms<200cfu/100mL); 2)   All flows from 227L/s up to 568L/s to receive partial disinfection (performance criteria faecal coliforms<1000cfu/100mL).
Undertake an investigation of the other recommendations identified in the report “Batemans Bay STP, Briefing Note 1 – Optimisation” to improve the optimisation of the sewage treatment plant including but not limited to the following: 1) Feasibility study into the installation of RAS flow meters for each clarifier so that RAS imbalances and the associated loss of plant capacity can be assessed and alarmed. 2) Feasibility study into flow pacing RAS. 3) Installation of duty/standby variable speed WAS pumps.
The licensee is permitted to temporary use explosives onsite for the purposes of a new cell/ pad construction to pop large boulders to enable clearing for a stockpile/ turnaround bay.
The temporary use of explosives onsite is to only allow for the splitting of existing larger boulders to be split into smaller fragments which can be more easily managed by machinery.
The temporary use of explosives onsite is permitted between 5 August 2024 and 1 January 2025 only.