WASTEWATER STED Schemes The septic tank effluent disposal (STED) schemes so popular in SA country townships, started with the installation of a scheme at Pinnaroo in 1962. Effluent is collected by common drains from the septic tanks in an area or
township and treated locally. The treatment used to be by oxidation and stabilisation lagoons, with the secondary effluent being discharged to nearby creeks or to evaporation lagoons or pans as they were usually called. In some cases, the common effluent was
Table 1 Reclaimed water reuse from various town STED lagoon systems Location
Reuse purpose
EP
Birdwood-Gumeracha Berri Barmera
950 6,000 4,300 3,100 800 600 400 600 2 000 1500 500 6000 1,100 800 1,200 800 3,500 800 2,600 1250 2500 5,000
Clare Cleve
Cummins
Echunga Eudanda
Kadina Kingscote Lameroo Loxton Lyndoch
Meningie
Penola Pinarroo Goolwa Robe
Strathalbyn Streaky Bay
Tanunda
Willunga-Mclaren Vale Total
Irrigation of oval Irrigation of race course Tree irrigation Mixed with gw-golf course irrigation Irrigation of oval Mixed with sw-local reuse Mixed with sw-golf course irrigation Local reuse Irrigation of playing fields Golf course irrigation Mixed with sw-golf course irrigation Mixed with fruit juice waste-woodlot irrigation Vineyard irrigation Irrigation of golf course Irrigation of 33 ha grass land Mixed with sw golf course Irrigation of woodlot Irrigation of sand dunes Equestrian and polo fields irrigation Irrigation of ovals and green areas in the town Vineyard irrigation Wetlands + irrigation of golf course
46,300
Source: Local Government Association Records, SA Health Commission approvals
Table 2 Reclaimed water reuse from compact wastewater treatment plants Location
Reuse purpose
EP
1,000 3,000 1,000 300 4,200 6,500 500 500 17,000
Black Point Coober Pedy Maitland Mt Compass Normanville-Yankalilla Renmarl< Roseworthy Southend Total
Tree plantation Irrigation of school oval Recreational areas Golf course irrigation Golf course irrigation Irrigation of ovals and green areas in the town Irrigation of ovals Irrigation of dedicated areas
Source: SA Health Commission approvals
\
•ADELAIDE ·c1eland
FLEURIEU PENINSULA
Goober Pedy
• Echunga • Mclaren Vale
•willunga
Normanville
•Yankalilla Wirrina
) GREAT AUSTRALIAN BIGHT
Note: 1. Reuse schemes arc indicated in dots ( •)
EYRE PENINSULA
Clare
Kadina
. Pomt
Eudunda ~enm~r1< • Bannera• Ben
Maitta~
1 , Roseworth~ .Tanunda Pearce 4 ) •. Lyndoch Black • 81rdwood Y O R K ~Point Osborne
PENINSU
SOUTH A U S T R A L I A
•
ADELAl;E .)
(see ,n,e/t)-=
Loxton
discharged to SA Water (then EWS) sewerage systems without further treatment. According to a SAHC report on the history of septic tank effluent disposal schemes (revised in June 1992), there were 962 km of STED drains in 88 townships. Only a small percentage of the early STED schemes involved reclaimed water reuse. In some schemes, use was achieved by mixing the effluent with stormwater or groundwater. Certain schemes did not have any reuse systems but incorporated them later. In other cases, existing reuse systems were extended. The STEDs serving various towns that have lagoon systems for treatment and incorporate reclaimed water reuse are shown in Table 1. Most of these systems were installed in the late 1960s and 1970s. One of the more recent of these reuse schemes at Tanunda started about 15 years ago with a mutual agreement between the winery growers in the area, whereas the Robe system was installed in 1987. Reclaimed water reuse from Streaky Bay (commissioned in 1992), Willunga and Lyndoch (both commissioned in 1995) are even more recent. At some townships, as the population the lagoons became increased over-loaded with increased flows. Consequently, the practice of discharging secondary efiluent to water courses became less and less acceptable by legislation and by perception. The recent trend is towards upgrading some of the existing STEDs treatment systems by replacing the lagoons with more compact treatment plants providing secondary or further treatment with reclaimed water reuse. Reuse schemes with compact WWTPs are summarised in Table 2. At Renmark, a 6500 EP package treatment plant has replaced the existing STED lagoons which are to be used for emergency overflows only. All the efiluent is to be used for irrigating sport grounds in the town, the high school oval, the main road median strip and the greening of the old railway land. Coober Pedy's system, built in 1994, reuses reclaimed water to irrigate a school oval with a subsurface irrigation system. At Black Point, Central Yorke Peninsula, 220 holiday homes are to be connected to the system. About six ha of land with sandy soils, 200 metres from the coast, is to be planted progressively with about 10 000 trees. There are several other schemes under construction or at the commissioning stage, like SouthenJ, Roseworthy and Normanville-Yankalilla STED schemes.
Other Applications Dual reticulation. In 1995-for the first time in SA-a communal, sewage-
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