Mudgee Sewage Treatment Plant

Project Description

The Mudgee Sewerage augmentation had a cost of approximately $25m with PCI’s portion being $15m. PCI constructed everything in this aerial photograph which involved 2 years of work from the ground up.

Mudgee STP

Below are links to an article from the local Mudgee newspaper and a video on Prime 7:

Mudgee STP

Project Details

Mudgee Sewage Treatment Plant Augmentation
Mid-Western Regional Council
D & C 16,000EP IDEAT Treatment Plant
60 weeks
2013
$15m

Case Study

This contract included the completion of design, supply of all materials, plant equipment and labour required for the construction, installation, testing and commissioning of the works in accordance with the supplied specifications and drawings.

The Mudgee Township was serviced by the original Mudgee sewage treatment plant (STP) located about 2.5 km north-west of Mudgee. The Mudgee STP was originally constructed in 1933 and had undergone two major augmentations since then, in 1961 and again in 1991.

The STP was operating above its design capacity and needed to be upgraded to cater for residential growth and to reduce pollutant loads on the receiving Cudgegong River. Discharges to the Cudgegong River were licensed by the EPA (now part of the DECCW – Department of Environment, Climate Change and Water).

According to recent census data (2006) Mudgee had a permanent population of approximately 8,800 persons, which is forecast to grow to some 14,000 persons by 2031. The load on the plant in 2031 has been estimated to be 16,000 EP, after allowing for commercial/industrial contributions.

The augmentation of the Mudgee Sewerage System was based on the replacement of the existing plant with a new STP based on primary treatment, secondary extended aeration activated sludge and disinfection processes.

The new Mudgee STP was designed for an equivalent population of 16,000 EP by 2031 (Stage 1), with provision to augment the plant to serve an additional 8,000 EP beyond 2031 (i.e. Stage 2 – 24,000 EP). Based on recent flow data, the Average Dry Weather Flow (ADWF) per person is 240 L/EP/d. A dry weather diurnal variation with a peak to average flow ratio of approximately 2.1 to 1 has been adopted for the purposes of designing the STP.

Design annual flows for the scheme were estimated assuming that wet weather flows contribute an additional 15% to the total annual flow calculated on a dry weather basis. It was also assumed that the maximum volume of septic waste received per day, and the maximum volume of leachate from the new landfill, was 30 kL each. These flows were taken into account for the calculation of the Average Dry Weather Flow (ADWF) and Peak Wet Weather Flows (PWWF) from the service area.