Odour From Pollution Control Centres

WHAT KINDS OF ODOUR?

• Most of the odours that come from wastewater treatment plants are the result of anaerobic decomposition of organic matter that we have eaten but only partially digested.
• Most of the unpleasant odours that result from this anaerobic decomposition are based on either
  • nitrogen (N) containing compounds or
  • sulphur (S) containing compounds, found in drinking water or the food we eat.
• Proteins are particularly bad sources of unpleasant odours since all proteins contain a significant fraction (15-18% by weight) of nitrogen and some also contain sulphur (up to 2.5% by weight). In contrast, carbohydrates and fats do not contain nitrogen, however, some contain sulphur.
• Some of the odours that come from a wastewater treatment plant include:
  • ammonia
  • amines
  • mercaptans
  • hydrogen sulphide
  • dimethyl sulphide
  • dimethyl disulphide

WHAT IS BEING DONE TO CONTROL ODOUR FROM POLLUTION CONTROL CENTRES?

The following activities serve to reduce or eliminate odours:

• Addition of ferrous chloride to the wastewater collection system reduces the release of hydrogen sulphide gas;
• Controlling the air from processes such as biosolids dewatering, solids contact, grit tanks and biosolids digestion;
• Treating the controlled, captured process air through chemical scrubbers, bio-filters and UV light.

In addition:

• An ion generator has been installed at Wellington Pump Station to reduce odours.
• Depending on the performance at Wellington Pump Station, an ion generator may be installed at Departure Bay Pump Station

To learn more about our projects and developments, please visit our Treatment Plant Developments Page.

How can I get more information?

Contact the Liquid Waste Department
Nanaimo Area: (250) 390-6560
Parksville/Qualicum Beach Area: (250) 954-3792
Toll Free in BC: 1-877-607-4111
Fax: (250)390-1542
E-mail: liquidwaste@rdn.bc.ca