Grace Tjandraatmadja

Impediments and constraints in the uptake of water sensitive urban design measures in greenfield and infill developments.

Water sensitive urban developments are designed with integrated urban water management concepts and water sensitive urban design measures. The initiatives that may be included are the substitution of imported drinking water with alternative sources using a fit-for-purpose approach and structural and non-structural measures for the source control of stormwater. A water sensitive approach to urban development can help in achieving sustainability objectives by minimising disturbance to ecological and hydrological processes, and also relieve stress on conventional water systems. Water sensitive urban developments remain novel in comparison with conventional approaches, so the understanding and knowledge of the systems in regards to their planning; design; implementation; operation and maintenance; health impacts and environmental impacts is still developing and thus the mainstream uptake of these approaches faces many challenges. A study has been conducted to understand these challenges through a detailed literature review, investigating a large number of local greenfield and infill developments, and conducting extensive consultation with water professionals. This research has identified the social, economic, political, institutional and technological challenges faced in implementing water sensitive urban design in greenfield and infill developments. The research found in particular that there is the need for long-term monitoring studies of water sensitive urban developments. This monitoring is important to validate the performance of novel approaches implemented and improve associated guidelines, standards, and regulatory and governance frameworks, which can lead to mainstream acceptance of water sensitive urban development approaches. The dissemination of this research will help generate awareness among water professionals, water utilities, developers, planners and regulators of the research challenges to be addressed in order to achieve more mainstream acceptance of water sensitive approaches to urban development. This study is based on existing water sensitive urban developments in Australia, however, the methodology adopted in investigating impediments to the uptake of these developments can be applied globally. It is hoped that insights from this study will benefit water professionals in other countries where there is also a move towards water sensitive urban development.

Adapting to climate change through urban water management: a participatory case study in Indonesia

The benefits of integrated approaches to climate risk and adaptation studies are increasingly recognised. Thus, there is an increasing need for practical examples of such work in the literature. This paper describes a practical application of an integrated framework for climate change impacts on regional surface water resources and the urban water system in the Mamminasata metropolitan region, Indonesia. Two main features of the framework are: the integration of both climate and other physical and social considerations in the assessment; and the high stakeholder involvement before, during and after project implementation. Although the study is concerned with the Mamminasata region, the overall methodology is transferable to any region in Indonesia or internationally. Key outcomes from this study are: (1) creation of information for Mamminasata planners and water resources managers for when, and under what conditions, the water supply may or may not meet the demand; (2) a clear consensus and shared learning of the problems facing the region among cross-institutional stakeholders; and (3) identification of adaptation options for the urban water system and knowledge gaps and strategies for their implementation. Results of stakeholders’ surveys conducted at the mid-point and at the end of the study indicate that these outputs will provide valuable guidance for future planning and management of Mamminasata regional water resources.

Sustainable sewerage servicing options for peri-urban areas with failing septic systems

The provision of water and wastewater services to peri-urban areas faces very different challenges to providing services to cities. Sustainable solutions for such areas are increasingly being sought, in order to solve the environmental and health risks posed by failing septic systems. These solutions should have the capability to reduce potable water demand, provide fit for purpose reuse options, and minimise impacts on the local and global environment. A methodology for the selection of sustainable sewerage servicing systems and technologies is presented in this paper. This paper describes the outcomes of applying this methodology to a case study in rural community near Melbourne, Australia, and describes the economic and environmental implications of various sewerage servicing options. Applying this methodology has found that it is possible to deliver environmental improvements at a lower community cost, by choosing servicing configurations not historically used by urban water utilities. The selected solution is currently being implemented, with the aim being to generate further transferable learnings for the water industry.

Vulnerability of water services in Pacific Island countries: combining methodologies and judgment

Water services in Pacific Island Countries are particularly vulnerable due to a range of circumstances such as the scale of operation, remoteness of location, financial constraints, cultural complexity and the ability to access technical and other capacity by their administrations. Additionally, the authors argue that comparative assessment of water needs for differing locations is fraught with difficulty because of the combination of systemic complexity, diversity of situations and lack of suitable, consistent and objective data. In these challenging situations, a method for assessment of the vulnerability of water services has been developed on the basis of knowledge and experiences of water professionals, elicited using a structured group interaction known as a Delphi survey. The Delphi survey has been undertaken with a range of stakeholders including panels of experts, funding agencies and local decision makers. Through the Delphi process, key factors contributing to vulnerability have been identified and the output has been used to develop an index methodology. Such an index methodology, similar to the Climate Vulnerability Index, has a number of dimensions, variables and appropriate weights expressed within a set of equations. Given quantification of variables, this method can be used to assess the relative vulnerability of water services in Pacific Island Countries. The method used to develop this index could also be applied to other contexts where appropriate.

Resource Recovery from Wastewater: A Research Agenda

Traditionally wastewater treatment involved the removal of pollutants from wastewater to allow it to be discharged to the environment. This initially concentrated on carbon removal, but as environmental requirements became more stringent it was expanded to cover nitrogen and phosphorus removal. With increasing energy costs, more stringent environmental discharge limits and greater implementation of water sensitive urban design the economic viability of recovering water, energy and resources from wastewater is being considered more seriously. There are many examples worldwide of wastewater reuse and the methodologies are well known for the recovery of water which represents the most valuable resource in wastewater. On the contrary, the widespread application of energy, nitrogen and phosphorus recovery is just beginning to gain traction. A range of technological options for recovery of resources from wastewater are discussed in this report and in order of recovered value they include: 1) energy from methane capture, 2) direct phosphorus recovery, and 3) biosolids with improved phosphorus bioavailability. At this stage it is considered that the recovery of nitrogen via ammonia requires a step-change in technology for energy-efficient capture. Anaerobic wastewater treatment and more efficient anaerobic digestion of sludge offers major opportunities to improve the energy efficiency of the wastewater sector and to decrease biosolids levels, especially if additional sources of carbon can be included in the digestion process. However this raises the issue of the biologically un-available (refractory) carbon and how it can be converted to make it biologically available. With regards to nitrogen recovery an industry survey indicated this to be a lower priority than carbon or phosphorus recovery. However, as carbon recovery becomes more commonplace viable nitrogen removal technologies will be needed as carbon will not be available for this process. Therefore as energy costs continue to increase and existing plants start to age and need replacement or upgrading, it is considered that low footprint/low energy nitrogen removal technologies such as Anammox and Aerated Granular Biomass will become the industry norms in the future, compared to traditional nitrification/denitrification treatment. Phosphorus removal and recovery technologies that form an integral component of these processes for dilute wastewaters would seem to be the obvious pathway for future development, as processes for the recovery of phosphorus from concentrated side-streams such as struvite are well advanced. The most obvious methods would appear to be based on biological (such as phosphorus accumulating organisms – PAOs) or physical adsorption processes. Whilst efficient resource recovery is deemed as feasible, wastewater treatment will still leave a smaller sludge stream. In parts of Europe incineration is the preferred disposal option and opportunities are seen here for the simultaneous production of biochar and biogas. However, for many countries land application is still preferred. With this option, knowledge is still needed to understand the nutrient availability from biosolids relative to inorganic fertilizers. It is recognised that whilst resource recovery may not be a major revenue stream for wastewater treatment plants (WWTPs), it will help in offsetting treatment costs required to meet environmental goals. In this respect the commercial, regulatory and customer service aspects of resource recovery adoption still need to be addressed. This title belongs to WERF Research Report Series . ISBN: 9781780406640 (eBook)

Headspace gas chromatography with flame ionization detection (HS-GC-FID) for the determination of dissolved methane in wastewater

There is currently a need for a simple, accurate and reproducible method that quantifies the amount of dissolved methane in wastewater in order to realize the potential methane that can be recovered and account for any emissions. This paper presents such a method, using gas chromatography with flame ionization detection fitted with a GS-Gas PRO column coupled with a headspace auto sampler. A practical limit of detection for methane of 0.9 mg L(-1), with a retention time of 1.24 min, was obtained. It was found that the reproducibility and accuracy of the method increased significantly when samples were collected using an in-house constructed bailer sampling device and with the addition of 100 μL hydrochloric acid (HCl) and 25% sodium chloride (NaCl) and sonication for 30 min prior to analysis. Analysis of wastewater samples and wastewater sludge collected from a treatment facility were observed to range from 12.51 to 15.79 mg L(-1) (relative standard deviation (RSD) 8.1%) and 17.56 to 18.67 mg L(-1) (RSD 3.4%) respectively. The performance of this method was validated by repeatedly measuring a mid-level standard (n=8; 10 mg L(-1)), with an observed RSD of 4.6%.