General

There are a variety of both proprietary and non-proprietary gross pollutant traps. Monitoring of the traps will depend upon whether they are designed to be self-draining (dry storage) or permanently inundated (wet sump).

Traps can be monitored for material capture (quantity and composition) including sediment quality, as well as water quality. Water quality monitoring can be performed on base flows (inter-event) and/or storm events at sample locations above and below each trap (concentration-grab or load sampling). The type and extent of monitoring will depend upon the questions being asked and the available budget.

Stormwater Extension Officer Program
Urban Stormwater FAQs
http://www.stormwater.org.au/faq.htm

Protocols

i) Material monitoring and cleanout:
Inspection of traps – after 10mm of rainfall within 24 hr period
Cleaning of traps – when >30% of capacity
Material volumes recorded (litres or cubic metres) and/or weight (wet or dry in kilograms) and percentage composition (litter, organic matter, sediment).

See Hornsby Shire Council Report on Maintenance and Monitoring
http://www.hornsby.nsw.gov.au/environment/index.cfm?NavigationID=925

ii) Water quality monitoring:
Device performance – in-situ probes, auto-samplers, manually
General: Turb, pH, DO, Temp, Conductivity, REDOX, SS, Nuts, FCols, flow rate
Wet Sumps: As General plus Metals, Oils & Grease, PAH’s

iii) Sediment monitoring:
Particle size analysis, TOC, Nuts, Metals, PAH’s.

Costs

Material monitoring – inspection approx $10-$50 per unit
Cleanout – approx $30-$1000 per unit (excluding disposal)
Purchase multi-probe approx $7,000 - $20,000
Maintenance and Calibration approx $2,000 pa
Establishment of auto-sampler approx. $20,000-30,000 pa

Case Studies

Hornsby Shire Council:
Catchment Remediation Capital Works Program Annual Report 2002-2003
www.hornsby.nsw.gov.au/environment/water catchments/catchment remediation program/

Stormwater Extension Officer Program
Stormwater Quality Improvement Devices
http://www.stormwater.org.au/sqids.htm

Allison, R.A., Chiew, F.H.S. & McMahon, T.A. (1997) Stormwater Gross Pollutants Industry Report, CRC for Catchment Hydrology, Australia.

Allison, R.A., Walker, T.A., Chiew, F.H.S., O’Neill, I.C. & McMahon, T.A.(1998) From Roads to Rivers Gross Pollutant Removal from Waterways, Technical Report 98/6, CRC for Catchment Hydrology, Australia.

WBM Oceanics Australia (2003) Review of Proprietary Stormwater Treatment Devices. Prepared for NSW EPA and Project Partners.

People Contacts

Anthony Collins, Hornsby Shire Council phone 02 9847 6860
http://www.hornsby.nsw.gov.au/environment/index.cfm?NavigationID=925

CRC For Freshwater Ecology
http://enterprise.canberra.edu.au/WWW/www-crcfe.nsf/d87a31d8f4603d1d4a256641000e9021/7e16e5963b71476b4a25664a004a2493?OpenDocument

Robin Allison, CRC for Catchment Hydrology phone 03 9905 2704
CRC for Catchment Hydrology
http://www.catchment.crc.org.au/

Mark Sabolch, Willoughby City Council phone 02 9777 1000
http://www.willoughby.nsw.gov.au

Organisation Contacts

CRC for Catchment Hydrology
http://www.catchment.crc.org.au/