ULLADULLA OUTFALL

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Monitoring Results

# Indicator Bacteria

Faecal coliform results indicated that the disinfection had been successful in ensuring that levels were well below NHMRC guidelines for recreational use at the two locations on Racecourse Beach that were tested and are regularly used for bathing.

## Biological Studies

May (1981, 1985)

Found that sewage effluent:

- Changed the number of species of intertidal flora at the outfall (some increased some decreased). Of the 31 species recorded in 1974, nine (Centroceras clavulatum, Cladophora repens, Codium cuneatum, Griffithsia monilis, Helminthocladia dotyi, Jania sp., Padina fraseri, Plocamium cartilagineum and Rhodymenia australis) did not occur after the commissioning of the outfall. A further three species (Ceramium sp., Nemalion multifidum and Phyllospora comosa) of the original 31 were not recorded after the 1975-76 period. Splachnidium rugosum was present less often during the later years. Two species (Bangia fuscopurpurea and Enteromorpha intestinalis) appeared soon after the sewage outfall was commissioned and remained throughout the period of study. Chaetomorpha aerea appeared later. Some species (e.g. Calothrix crustacea, Dictyota dichotoma and Lophosiphonia reptabunda) appeared in only one year. Eighteen species occurred throughout the study period: 12 of these showed no obvious change in abundance, while four (Enderachne binghamiae, Laurencia brongniartii, L. filiformis and Sargassum lophocarpum) decreased in abundance; and two (Ralfsia sp. and Porphyra columbina) increased in abundance. Ulva lactuca was common on much of the headland prior to the installation of the outlet and retained its position near the outlet pipe throughout the period of study. Gelidium pusillum did not appear until October 1978, but by June 1979 was the dominant plant nearest the outfall.

Methods

May investigated the intertidal floras before and after the commissioning of the outfall in September 1975.

Outfall Site

Faecal Coliform

Outfall

Ulladulla

(Ulla_7) Last updated June 2000