Tag Archives: wastewater recycling

Japan: selling sewage to Australia

Japan has an unlikely new export product:  the sewage it normally dumps into rivers or the sea. The first buyer is the Australian mining industry. Could this also become a new money earner for developing countries? Well, no. The “export quality” sewage in question is effluent from high-tech Japanese wastewater treatment plants.

An innovative trade experiment will take place in the autumn of 2010. Australian ships with iron ore for Japan, will return, not with seawater in their ballast tanks, but with highly treated sewage water.

Australia is facing a water shortage and mines need a lot of (expensive) water for their operations. If all goes well, the cost of Japan’s sewage water will be less than the AU$ 4 to AU$5 (US$ 3.50 – US$ 4.40) per ton that the mining companies currently have to pay.

Companies involved in the experiment, including Hitachi Plant Technologies Ltd., plan to start sewage water exports on a commercial basis in fiscal 2012. The state of Western Australia, home to major mining companies such as Rio Tinto, has agreed to cooperate in the experiment.

In Japan, about 14 billion tons of treated sewage water is produced every year, but only 1.5 percent of the amount was reused in 2007.

Source: Dai Narusawa, Asahi Shimbun, 07 Jul 2010

India, Mumbai: soon, water recycling a must for high-rises

Mumbaikars residing in high-rises will soon have to switch their water consumption patterns so that residents of smaller housing societies get their quota of the municipal water supply. The Law committee of the Brihanmumbai Municipal Corporation (BMC), on Tuesday [22 June 2010], unanimously approved by-laws that make recycling of grey water (wastewater) mandatory for all high-rises, which have sufficient space to create a wastewater collection and recycling plant.

According to the by-laws, housing premises with an area of more than 2,000 square metres, or premises that have more than 60 dwellings will be required to recycle wastewater. The rule will also be applicable for all those buildings, societies and townships where the daily municipal water consumption is above 60,000 litre.

While the rule is applicable to all new constructions, it will also cover existing structures that fall in the criteria and have adequate space to create the treatment facility. The only exception made is for structures where such a facility can’t be created due to structural or physical reasons.

According to a senior engineer from the sewerage department, the move is aimed at limiting the usage of municipal water only for potable purposes. “The recycled greywater could be used for most non-potable purposes,” the engineer said. The BMC is hoping to save at least 200 million litres of water daily by implementing the rule. The water saving, said a hydraulic department official, numerically put, would be able to quench the thirst of 22 lakh [2.2 million] people.

To make existing buildings comply with the norm, the BMC has decided to levy a minimum fine of Rs5,000 [US$ 107] on those who refuse to setup a treatment facility. According to the civic official, creating a water treatment facility was cost-effective and in the long-term interest of even the societies.

“The water bill will go down substantially as the water consumption will decrease,” the official said. “The setting up of such a facility could cost a society anywhere between Rs5-7 lakh [US$ 10,700-15,000]. To encourage citizens to back the green initiative, the BMC has also proposed a 25% rebate in water and sewerage tax.”

The by-laws will now be put before the civic general body meeting before being incorporated as a law. The process will take about two months, added the official.

Source: Sandeep Ashar, DNA, 24 Jun 2010

Strengthening capacities for planning of sanitation and wastewater use : experiences from two cities in Bangladesh and Sri Lanka

Smits, S., Da Silva Wells, C. and Evans, A. (2009). Strengthening capacities for planning of sanitation and wastewater use : experiences from two cities in Bangladesh and Sri Lanka. The Hague, the Netherlands, IRC International Water and Sanitation Centre (Occasional Paper Series 44). 56 p. ; 5 fig., 6 tab. 37 ref.
Download full text

Executive Summary

It is well-known that many peri-urban communities use wastewater (often untreated) in agriculture. Although wastewater-dependent agriculture provides livelihoods to farmers, there are associated health and environmental risks. The roots of this situation lie in the poor sanitation in cities where part of the population doesn’t have access to basic sanitation services at all, where domestic wastewater is not properly collected or is discharged into open water bodies without any treatment, and where industrial discharges and dumping of solid waste often add to the pollution problem.

The basic premise of the Wastewater Agriculture and Sanitation for Poverty Alleviation (WASPA) in Asia project is that by integrated planning both the lack of sanitation services and the health and environmental risks associated with wastewater use in agriculture can be addressed simultaneously. The idea is to improve conditions along the entire sanitation chain (from household latrines to collection, treatment and reuse of wastewater), while maintaining the characteristics of wastewater valued by farmers, such as nutrient content.

This concept was tested in two towns: Rajshahi in Bangladesh and Kurunegala in Sri Lanka. The project worked through Learning Alliances, composed of local stakeholders, including farmers, residents, small industries and local authorities. With these Learning Alliances, the current situation was analysed, and integrated plans for improvement were formulated and executed in a collaborative manner with a range of stakeholders. This document provides an overview of the experiences of the project and provides a critical reflection on the WASPA concept and its applicability.

The project found that the sanitation situation in both cities was less severe than originally hypothesised. Lack of access to basic sanitation only contributed in a minor way to wastewater flows. Instead, other sources of pollution were identified, such as discharges from small industries and leakage from poorly maintained or inadequate septic tanks. At the same time, the impacts of wastewater agriculture on crop yields and health risks were less than expected.

The situation also proved to be more complex than originally thought, necessitating that a broader range of stakeholders be involved in the identification and implementation of solutions. The multi-stakeholder approach of Learning Alliances and participatory planning cycle provided a useful framework for addressing this complex problem. It allowed examination of the entire sanitation chain and identification of potential strategies for
improvements along the entire chain. In addition, it provided a way of gradually building up relations between stakeholders in a context characterised by institutional fragmentation, conflict and poor accountability. Over time, relations improved and more integrated planning emerged.

A potential drawback to the approach is that stakeholders tend to identify isolated and conventional actions to address the situation, and thus need strong facilitation and increased knowledge to arrive at appropriate solutions. Also, transaction costs of the approach are high, in terms of getting the teams in place, starting up the multi-stakeholder process, and getting stakeholders to carry out a joint planning exercise and subsequently implement their plans. However, the project demonstrated that integrated, joint planning is important for addressing complex problems that span sectoral, administrative and social divides and that, ultimately, the high transaction costs are justified.

India, Hyderabad: Wastewater quality and the risk of intestinal nematode infection in sewage farming families

Ensinkm, J.H., Blumenthal, U.J., Brooker, S. (2008).  Wastewater quality and the risk of intestinal nematode infection in sewage farming families in Hyderabad, India. American journal of tropical medicine and hygiene ; vol. 79, no. 4 ; p. 561-567. Abstract and link to full text here

Use of sewage or wastewater in agriculture is becoming increasingly common as a result of a global water scarcity. Intestinal nematode infections have been identified as the main health risk associated with this practice. To protect consumer and farmer health, the World Health Organization (WHO) has established an intestinal nematode water quality standard. However, because of a lack of well-designed studies, the validity of this guideline is questioned. This report presents the findings of a study on the risk of intestinal nematode infections in farming families occupationally exposed to untreated and partially treated wastewater in Hyderabad, India. The study found an increased risk of hookworm (odds ratio [OR] 3.5, 95% confidence interval [CI] = 2.2-5.5), Ascaris lumbricoides (OR = 5.3, 95% CI = 2.0-14), and Trichuris trichiura (OR = 5.6, 95% CI = 1.8-18) infection when untreated wastewater (150 intestinal nematode ova/liter) was used for crop production. Use of partially treated wastewater (28 intestinal nematode ova/liter) was only associated with an increased risk (OR = 3.2, 95% CI = 1.2-8.6) of A. lumbricoides infection. The findings of the study suggest that the current WHO intestinal nematode guideline of 1 ova/liter is sufficient to protect farmer health.

Related publication: WHO (2006). Guidelines for the safe use of wastewater, excreta and greywater. Geneva, Switzerland, World Health Organization (WHO). Download here

Contact: Jeroen H. J. Ensink, Department of Infectious Diseases and Tropical Diseases, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, United Kingdom. E-mail: jeroen.ensink@lshtm.ac.uk