wastewater design report

6.0 DEFINITIONS

Advanced Secondary treatment system - These systems treat domestic wastewater to
10 mg/L BOD; 10 mg/L TSS standard or better prior to discharge to the land
application area.

Biochemical oxygen demand (BOD) - A measure of the amount of oxygen used in
the biochemical oxidation of organic matter, over a given time and at a given
temperature; it is determined entirely by the availability of the material as a biological
food and by the amount of oxygen used by the microorganisms during oxidation.
Blackwater — Wastes discharged from the human body either directly to a composting
toilet or through a water closet (flush toilet) and/or urinal and the water used for the
discharge.

BODs- BOD determined by standard test (5 days at 20°C).

Design Loading Rate (DLR) — The loading rate secondary or advanced secondary
effluent can be applied to the soil of a disposal system expressed in mm/week
Effluent — Sewerage, water or other liquid partially or completely treated or in its
natural state flowing out of a septic tack, aerated wastewater treatment system, sand
filter or other treatment system or treatment component.

Expected available area — Areas, which at the time of evaluation have no physical
constraints to inhibit the design, instillation, operation and maintenance of disposal.
Greywater — The domestic wastes from a bath, shower, basin, laundry and kitchen but
excluding toilet and urinal wastes.

Intermittent watercourse — A natural or artificial stream or channel, identifiable by
recognisable bed and banks, along which rainwater or storm water usually or
occasionally flows.

Land application area — The area over which the treated effluent is evenly applied.
Land application facility/system —Is a facility for treatment, re-use or sustainable
disposal of effluent from a treatment plant on land under controlled conditions.
On-site sewerage treatment plant — Includes septic tanks, aerated wastewater
treatment plants, sand filters, wet composting toilets etc.

Permeability — (P - m/day) calculated value derived from the rate at which a head of
liquid is absorbed into a soil.

Primary treatment system - These systems treat domestic wastewaters to 120-240
mg/L BODs, 65-180 mg/L TSS standard or better prior to discharge to the land
application area.

Reserve Area — an area set aside for future use as a Land Application Facility to
replace or extend the original system.

Secondary treatment system - These systems treat domestic wastewater to 20 mg/L
BODs, 300 mg/L TSS standard or better prior to discharge to the land application area.
Sewerage - The wastewaters from the community, including all faecal matter, urine,
household and commercial wastewaters that contain human waste.

Surface Horizontal Setback Distances — Separation distances from watercourses,
dams, drainage channels, bores, wells, boundaries, paths, dwellings etc.

Total suspended solids (TSS) - The portion of total solids retained on a glass fibre
filter with a nominal pore size 2 microns, measured after being dried at a 103-105°C.
Vertical Setback Distances — Separation distances from permanent watertable or
bedrock.

Wastewater — The spent or used water from human or household or commercial and
institutional activity that contains dissolved or suspended matter (sewage).

 

Unearthed Geotechnical P/L. 13 Design Report 022-003