Christopher Scott's Water Resources and Policy Group

Water Reuse

2009 Survey of existing users of reclaimed water in Tucson

WRPG member, Anne Campbell, researched the perceptions of existing users of reclaimed water in Tucson. With support from UA undergraduate honors student Octavio Ulloa and in coordination with UA graduate student Kerri Jean Ormerod (both WRPG members), she conducted a mail survey of 550 current users of reclaimed water in neighborhoods where Tucson Water offers it for residential landscape irrigation. She received 150 responses. The study found that users with intensive landscaping are happy with the system both in its cost-benefit and its ability to support their landscaping lifestyle choice. At the other end of the spectrum are low water landscaping residents who find the higher cost of reclaimed water (over their lowest tier potable use) and annual inspection and maintenance requirements to be a financial disincentive. Many use or are considering other alternatives such as grey water and rainwater harvesting. The City of Tucson similarly is encouraging individual residential users towards these alternatives as preferred cost-effective conservation measures. For all users, generally, there is a concern for water in Arizona and a wiliness to conserve even if for many it does cost a little more. For the City, use of reclaimed water for golf course and other intensive landscaping irrigation uses remain a priority.

UA undergraduate honors student, Octavio Ulloa, investigated the role of rainwater harvesting in Tucson and Pima County’s regional water sustainability planning. A variety of citizens’ groups, non-governmental organizations, and commercial providers of water harvesting systems are involved in spreading the adoption of this practice, which has the potential to offset water scarcity but requires additional support in the form of public education, rebates and subsidies, and enforcement of a recently passed city of Tucson ordinance mandating that water harvesting meet a share of outdoor water use on commercial properties.

2009-10 Water Reuse to Offset Growth-Driven Water Scarcity in the Southwest: From Supply Augmentation to Substitution (C. Scott, PI, 100%). $74,789, WateReuse Foundation.

2008-12 Optimization of Dual Conjunctive Water Supply and Reuse Systems with Distributed Treatment for High-Growth Water-Scarce Regions (C. Scott, co-PI, 20%). $ 1,999,558. National Science Foundation, Resilient and Sustainable Infrastructures (RESIN).

Fall 2009 New book: Drechsel, P., C.A. Scott, L. Raschid-Sally, M. Redwood, A. Bahri (Editors). Forthcoming (Fall 2009). Wastewater Irrigation and Health: Assessing and Mitigating Risks in Low-Income Countries. Earthscan, London. see more >>

Wastewater in Agriculture Accra Consensus Agenda for Research, Capacity Building & Action on the Safe Use of Wastewater and Excreta in Agriculture Rapidly expanding cities, escalating water scarcity, food supply and livelihood needs, particularly in low-income regions, are all driving the increasing demand for untreated and treated wastewater and excreta for agriculture. Although much progress has been made in our understanding of these issues since the ‘Hyderabad Declaration’ of 2002, significant challenges remain to make the use of wastewater and excreta in agriculture safe, economically productive, and sustainable.

We – an expert group from 30 international, regional, and national research institutes, multilateral and bilateral bodies, and universities based in 17 countries – emphasize the need to support policy makers around the world to make informed decisions that lead to cost-effective interventions that improve public health, promote sustainable sanitation, protect the environment, and support food security and economic development.

Achieving this goal requires consolidation of information on the science and practice of wastewater and excreta use, and well-targeted research to address gaps in the evidence base needed to support informed decision-making. Therefore, we propose the following multi-disciplinary agenda for action:

1. Integrate health and economic impact assessments to determine the actual contribution of wastewater and excreta use to the burden of disease, particularly in low-income settings, and to prioritize interventions to improve health and livelihood outcomes.

2. Facilitate the adoption of the 2006 World Health Organization guidelines for the safe use of wastewater, excreta and greywater in low-income settings through the development and application of appropriate local practices and standards that take into account local capacities and resources. Specifically:

• Fill data gaps on levels, transmission, persistence, and reduction of key pathogens along the environmental pathways from fecal origin to human exposure, and measure disease incidence among those exposed. • Rigorously evaluate – in multiple geographical contexts – a range of wastewater and excreta treatment approaches and other risk mitigation strategies for their cost-effectiveness and impacts on health, livelihood, and the environment.

3. Increase human, institutional, and technical capacities in low-income settings to:

• Detect important pathogens in human and environmental samples • Design and operate wastewater and excreta treatment systems that can be maintained in their ecological and economic context, and thereby support the safe and productive use of wastewater and excreta in agriculture • Develop and support effective participatory governance mechanisms for sustainable sanitation design and operation and safe and productive wastewater and excreta use.

4. Facilitate the exchange of information on best practices, including successful risk assessment and mitigation strategies, among partners around the globe through national and regional knowledge hubs and web-based data banks.

Accra, 9th October 2008

> CONSENSUS with signatories (PDF) > Hyderabad Declaration (PDF English) > Declaración de Hyderabad (PDF Spanish)