Background

Prior to Parklink’s involvement and treatment, the company had mechanically desludged but was experiencing severe solids accumulation and wash over into the neighbouring aerobic pond.

In December 2009 Parklink installed equipment onsite and treatment began in late January 2010.

Objectives

• To remove accumulated solids and eliminate the need for mechanical desludging.
• Reduce odour.
• Remove the solids without interruption to production.
• To maintain the solids accumulations at an optimum percentage and manage the level on a sustainable, ongoing basis.

Treatment Considerations

Parklink’s Sludge Removal programme removed the solids without the problems of mechanical extraction, material storage issues, smell, appropriate land area and drainage of leachates. We achieved a reduction of 663.5m³ of total dry solids in first 12 months. This equates to approximately 4,644 tonnes of non-centrifuged wet solids. Approximately 309 truck and trailer loads were removed.

Parklink provided reports that assisted the company’s management to make informed decisions around its obligations to the District Council and discharge permits. The plant is now operating a Parklink maintenance treatment programme designed to manage the suspended solids loading, leaving a good margin of clear liquid in the top zone.

After 4 years of treatment, the pond is working very efficiently and there is no need for any solids to be removed.

Engineers have reported that getting the effluent pumps operating each morning is no longer a chore that requires the pumps to be unblocked from accumulated material and they run more efficiently, impacting positively on the cost of maintenance.