RFI - Attachment F - Engineering Report

Test results show that with the addition of CFS, the majority of sediment down to 100 microns in size can be
removed.

If the removal of particles greater than 500 micron provides an opportunity to halt degradation or improve the
quality of the Auckland environment then a focus on standard catchpits would be a step in the right direction. If
the requirements are to remove down to 100 microns then the addition of a suitable CFS would equally be a step
in the right direction.

Identification of the relationship between sediment particle size removed and the volume of various pollutants
removed has not been part of this study.

DISCLAIMER

The intent of this paper has not been to proclaim any particular CFS brand name or supplier as being “better”
than another, The authors acknowledge that suppliers may have changed the character or form of CFS products
since this study was carried out, and this paper should not be used as a basis for users to select one product aver
another.

REFERENCES

DLWC (1998) ‘The Constructed Wetlands Manual’ Department of Land and Water Conservation, New south
Wales, Volume 2.

ABBREVIATIONS

CFS — Catchpit Filter Systems
T&T Tonkin & Taylor Ltd Environmental & Engineering Consultants Ltd