ON-SITE DOMESTIC WASTEWATER TREATMENT AND REUSE (original) (raw)

A Review of On-Site Wastewater Practices in South-East Queensland

This paper presents results from a 'census' of the status of on-site wastewater treatment systems (OWTS) management practices in the SEQ region as part of the Healthy Waterways initiative. The current number of on-site systems is estimated to be 127,000 with septic systems accounting for 80%. Key management issues were highlighted during the project, notably the frequency of greywater failure and inappropriate greywater discharge. Septic system failures were reported mainly in the newer combined septic systems that receive 100% of household water compared with the split blackwater systems that receive about 20%. Aerated systems were inadequately maintained. However, to date, no "smoking guns" of poor water quality from non-sewered catchments have been clearly identified. A clear outcome of this survey was the need for all SEQ Local Authorities to audit every on-site system. Predictions and assessment of catchment water quality risks from on-site systems would be gr...

AUSTRALIAN ON-SITE WASTEWATER STRATEGIES: A CASE STUDY OF SCOTLAND ISLAND, SYDNEY, NSW AUSTRALIA

2000

Australian urban centres are primarily situated along wetter and more humid coastal areas, with much of the dry continental parts of the country remaining relatively undeveloped. Approximately 12 % of the population, in excess of 2 million persons, are not serviced by reticulated sewerage facilities and rely solely on on-site management for the treatment and disposal of domestic wastewaters. A

Appropriate technology for domestic wastewater management in under-resourced regions of the world

Applied Water Science, 2016

Centralized wastewater management system is the modern day waste management practice, but the high cost and stringent requirements for the construction and operation have made it less attractive in the under-resourced regions of the world. Considering these challenges, the use of decentralized wastewater management system, on-site treatment system, as an appropriate technology for domestic wastewater treatment is hereby advocated. Adopting this technology helps save money, protects home owners' investment, promotes better watershed management, offers an appropriate solution for low-density communities, provides suitable alternatives for varying site conditions and furnishes effective solutions for ecologically sensitive areas. In the light of this, an overview of the on-site treatment scheme, at the laboratory scale, pilot study stage, and field trials was conducted to highlight the operational principles' strength and shortcomings of the scheme. The operational requirements for the establishing and operation of the scheme and best management practice to enhance the performance and sustenance were proffered.

On-site greywater treatment and reuse in multi-storey buildings

Water science and technology : a journal of the International Association on Water Pollution Research, 2005

The paper presents a study of a pilot plant treating light greywater for seven flats. The pilot plant combines biological treatment (RBC) with physicochemical treatment (sand filtration and disinfection). The pilot plant produced effluent of excellent quality, meeting the urban reuse quality regulations, and was very efficient in TSS turbidity and BOD removal: 82%, 98% and 96%, respectively. COD removal was somewhat lower (70-75%) indicating that the greywater may contain slowly-biodegradable organics. The RBC (attached growth biological system) was able to retain most of the solids as a result of bioflocculation; further it was proven to have very stable and reliable performance. Faecal coliforms and heterotrophic reductions were very high (100% and 99.99%, respectively) producing effluent that also met drinking water standards. The combination of low organic matter, nutrients and microbial indicators reduces the regrowth and fouling potentials in the reuse system, thus ensuring sa...

Greywater Reuse in a Sewered Area Design and Implementation at Research House

2005

In Queensland, the Plumbing and Drainage Act (2002) is being amended to allow greywater reuse in sewered areas. The greywater must be treated and applied in a safe manner for both public and environmental health. The Queensland State Government has built, in Rockhampton, a Research House as part of their "Towards Healthy and Sustainable Housing Research Project". Research House was built using water-efficient infrastructure and has two rainwater tanks (total capacity 7 kL). The Central Queensland University (CQU) was asked to design a greywater treatment and reuse system for the House. The proposed design incorporates a backflow prevention device on the water mains entry to the house. The harvested stormwater from the rainwater tanks will provide water for the hot-water system and laundry. This will reduce the amount of potable mains water required by the house and potentially provide softer water that should reduce the scaling in the hot-water system and require lower doses of detergents. The greywater from the laundry, shower, and vanity unit will be collected and primary treated in a deep vertical greasetrap. The primary treatment tank will have an overflow to the sewer. The primary treated greywater will be filtered and then used for subsurface irrigation. Research House has an established monitoring program that will be adapted to record the volumes of harvested stormwater and greywater reuse. Water quality parameters will be examined on a monthly basis. The proposed stormwater reuse and greywater treatment and reuse plan is expected to reduce the amount of reticulated mains-supplied water used by Research House by approximately 45%.

Health risks of reusing wastewater in urban developments: A case study approach in Western Australia

2016

Like many other cities, Perth is facing shortages of potable water. Water should be used as a sustainable resource so that it is available in future. The factors contributing to increasing water shortages include: an increasing population, decreasing rainfall, aging of existing supply system infrastructure, and continued inefficient water use. Efforts by the Western Australian community to overcome water scarcity include implementing garden watering restrictions, water efficient appliances, and the use of treated rainwater and the use of recycled water in a safe and sustainable manner to reduce pressures on limited drinking water resources. However, introducing wastewater as a source of water supply for non-potable water has its own limitations, including: pricing, health concerns, technology, and legislative challenges, all of which need to be addressed. A new concept of treating wastewater onsite for commercial reuse in Western Australia is being applied by the Peppermint Grove Co...

Potentials for greywater treatment and reuse in rural areas

… Symposium on Ecological …, 2003

This paper compares various ways to deal with greywater (wastewater from sources others than the toilet: e.g. kitchens, bathrooms and laundry) especially for small-scale solutions -single households and small settlements. General considerations on the treatment of greywater will be discussed as well as the advantages and disadvantaged of various treatment technologies. Finally possibilities and limitations for discharge and reuse of the end-product -treated greywater -will be discussed including health hazards. The investment and operational costs calculated for different scenarios of wastewater treatment for a single household with and without greywater separation and/or treatment show a clear economic advantage of the scenarios with greywater separation compared to the collection and treatment of the total wastewater.

Wastewater management and resource recovery in intensive rural industries in Australia

Water Research, 1992

Intensive rural industry is developing rapidly in parts of inland Australia. Also, coastal cities are investigating the use of sewage for crop growth, to avoid expensive treatment processes and pollution of rivers, streams and oceans. However, in the past, land spreading of manure and liquid effluent has sometimes degraded surface and groundwater quality irreversibly. Many surface waters are particularly vulnerable to phosphorus enrichment while some groundwaters are already heavily polluted with nitrates. Salt must be managed carefully to avoid degradation of soil fertility and structure in the longer term. Root zone accumulation of salt must be avoided by redistribution and storage in the landscape or by dilution in peak flows. The question is whether the nutient and water resources in effluents can be effectively and economically captured, so that water resources will be adequately protected from the cumulative effect of many small additions.

The importance of site assessment in designing effluent disposal areas

2001

This paper discusses a research project on on-site sewage treatment undertaken in the Brisbane area and will evaluate the treatment performance of on-site effluent disposal systems (septic tanks with absorption fields) and relate them to site and soil conditions. Detailed soil analysis was undertaken to evaluate soil physico-chemical characteristics at the study sites together with a comprehensive evaluation of site and landscape factors. The performance-based approach to domestic wastewater management introduced recently across Australia will result in a process in which site characteristics establish performance objectives for treatment and disposal. In designing and siting an on-site treatment system valuable information is derived not only by soil characterisation and terrain evaluation, but also observing geomorphologic features that are significant in relation to drainage. Soil chemistry can also add value in evaluating difficult sites. The results obtained confirmed the strong site specific nature of effluent renovation.

ASSESSMENT OF ENVIRONMENTAL AND PUBLIC HEALTH RISK OF ON-SITE WASTEWATER TREATMENT SYSTEMS

On-Site Wastewater Treatment X, 21-24 March 2004

On-site wastewater treatment systems are common throughout Australia, with most systems located in the urban fringe and rural regions. The number of on-site treatment systems is increasing rapidly as these areas undergo more intensive development. Consequently, there is a significant increase in environmental and public health risks associated with these systems. This has lead to the recognition of the need for the articulation of treatment standards and criteria which are flexible and robust to satisfy specific public health and environmental requirements. Currently, these concepts are not being widely applied in on-site treatment of wastewater.