Performance evaluation of onsite wastewater treatment : field sampling and preliminary evaluation of results

Background The onsite treatment of sewage and effluent disposal within the premises is widely prevalent in rural and urban fringe areas due to the general unavailability of reticulated wastewater collection systems. Despite the seemingly low technology of the systems, failure is common and in many cases leading to adverse public health and environmental consequences. Therefore it is important that careful consideration is given to the design and location of onsite sewage treatment systems. It requires an understanding of the factors that influence treatment performance. The use of subsurface effluent absorption systems is the most common form of effluent disposal for onsite sewage treatment and particularly for septic tanks. Additionally in the case of septic tanks, a subsurface disposal system is generally an integral component of the sewage treatment process. Therefore location specific factors will play a key role in this context. The project The primary aims of the research project are: • to relate treatment performance of onsite sewage treatment systems to soil conditions at site; • to identify important areas where there is currently a lack of relevant research knowledge and is in need of further investigation. These tasks were undertaken with the objective of facilitating the development of performance based planning and management strategies for onsite sewage treatment. The primary focus of the research project has been on septic tanks. Therefore by implication the investigation has been confined to subsurface soil absorption systems. The design and treatment processes taking place within the septic tank chamber itself did not form a part of the investigation. In the evaluation to be undertaken, the treatment performance of soil absorption systems will be related to the physico-chemical characteristics of the soil. Five broad categories of soil types have been considered for this purpose. The number of systems investigated was based on the proportionate area of urban development within the Brisbane region located on each soil types. In the initial phase of the investigation, though the majority of the systems evaluated were septic tanks, a small number of aerobic wastewater treatment systems (AWTS) were also included. This was primarily to compare the effluent quality of systems employing different generic treatment processes. It is important to note that the number of different types of systems investigated was relatively small. As such this does not permit a statistical analysis to be undertaken of the results obtained. This is an important issue considering the large number of parameters that can influence treatment performance and their wide variability. The report This report is the second in a series of three reports focussing on the performance evaluation of onsite treatment of sewage. The research project was initiated at the request of the Brisbane City Council. The work undertaken included site investigation and testing of sewage effluent and soil samples taken at distances of 1 and 3 m from the effluent disposal area. The project component discussed in the current report formed the basis for the more detailed investigation undertaken subsequently. The outcomes from the initial studies have been discussed, which enabled the identification of factors to be investigated further. Primarily, this report contains the results of the field monitoring program, the initial analysis undertaken and preliminary conclusions. Field study and outcomes Initially commencing with a list of 252 locations in 17 different suburbs, a total of 22 sites in 21 different locations were monitored. These sites were selected based on predetermined criteria. To obtain house owner agreement to participate in the monitoring study was not an easy task. Six of these sites had to be abandoned subsequently due to various reasons. The remaining sites included eight septic systems with subsurface effluent disposal and treating blackwater or combined black and greywater, two sites treating greywater only and six sites with AWTS. In addition to collecting effluent and soil samples from each site, a detailed field investigation including a series of house owner interviews were also undertaken. Significant observations were made during the field investigations. In addition to site specific observations, the general observations include the following: • Most house owners are unaware of the need for regular maintenance. Sludge removal has not been undertaken in any of the septic tanks monitored. Even in the case of aerated wastewater treatment systems, the regular inspections by the supplier is confined only to the treatment system and does not include the effluent disposal system. This is not a satisfactory situation as the investigations revealed. • In the case of separate greywater systems, only one site had a suitably functioning disposal arrangement. The general practice is to employ a garden hose to siphon the greywater for use in surface irrigation of the garden. • In most sites, the soil profile showed significant lateral percolation of effluent. As such, the flow of effluent to surface water bodies is a distinct possibility. • The need to investigate the subsurface condition to a depth greater than what is required for the standard percolation test was clearly evident. On occasion, seemingly permeable soil was found to have an underlying impermeable soil layer or vice versa. The important outcomes from the testing program include the following: • Though effluent treatment is influenced by the physico-chemical characteristics of the soil, it was not possible to distinguish between the treatment performance of different soil types. This leads to the hypothesis that effluent renovation is significantly influenced by the combination of various physico-chemical parameters rather than single parameters. This would make the processes involved strongly site specific. • Generally the improvement in effluent quality appears to take place only within the initial 1 m of travel and without any appreciable improvement thereafter. This relates only to the degree of improvement obtained and does not imply that this quality is satisfactory. This calls into question the value of adopting setback distances from sensitive water bodies. • Use of AWTS for sewage treatment may provide effluent of higher quality suitable for surface disposal. However on the whole, after a 1-3 m of travel through the subsurface, it was not possible to distinguish any significant differences in quality between those originating from septic tanks and AWTS. • In comparison with effluent quality from a conventional wastewater treatment plant, most systems were found to perform satisfactorily with regards to Total Nitrogen. The success rate was much lower in the case of faecal coliforms. However it is important to note that five of the systems exhibited problems with regards to effluent disposal, resulting in surface flow. This could lead to possible contamination of surface water courses. • The ratio of TDS to EC is about 0.42 whilst the optimum recommended value for use of treated effluent for irrigation should be about 0.64. This would mean a higher salt content in the effluent than what is advisable for use in irrigation. A consequence of this would be the accumulation of salts to a concentration harmful to crops or the landscape unless adequate leaching is present. These relatively high EC values are present even in the case of AWTS where surface irrigation of effluent is being undertaken. However it is important to note that this is not an artefact of the treatment process but rather an indication of the quality of the wastewater generated in the household. This clearly indicates the need for further research to evaluate the suitability of various soil types for the surface irrigation of effluent where the TDS/EC ratio is less than 0.64. • Effluent percolating through the subsurface absorption field may travel in the form of dilute pulses. As such the effluent will move through the soil profile forming fronts of elevated parameter levels. • The downward flow of effluent and leaching of the soil profile is evident in the case of podsolic, lithosol and kransozem soils. Lateral flow of effluent is evident in the case of prairie soils. Gleyed podsolic soils indicate poor drainage and ponding of effluent. In the current phase of the research project, a number of chemical indicators such as EC, pH and chloride concentration were employed as indicators to investigate the extent of effluent flow and to understand how soil renovates effluent. The soil profile, especially texture, structure and moisture regime was examined more in an engineering sense to determine the effect of movement of water into and through the soil. However it is not only the physical characteristics, but the chemical characteristics of the soil also play a key role in the effluent renovation process. Therefore in order to understand the complex processes taking place in a subsurface effluent disposal area, it is important that the identified influential parameters are evaluated using soil chemical concepts. Consequently the primary focus of the next phase of the research project will be to identify linkages between various important parameters. The research thus envisaged will help to develop robust criteria for evaluating the performance of subsurface disposal systems.

Analyzing the factors influencing the successful design and uptake of interactive systems to support social networks in urban neighborhoods

In urban residential environments in Australia and other developed countries, Internet access is on the verge of becoming a ubiquitous utility like gas or electricity. From an urban sociology and community informatics perspective, this article discusses new emerging social formations of urban residents that are based on networked individualism and the potential of Internet-based systems to support them. It proposes that one of the main reasons for the disappearance or nonexistence of urban residential communities is a lack of appropriate opportunities and instruments to encourage and support local interaction in urban neighborhoods. The article challenges the view that a mere reappropriation of applications used to support dispersed virtual communities is adequate to meet the place and proximity-based design requirements that community networks in urban neighborhoods pose. It argues that the key factors influencing the successful design and uptake of interactive systems to support social networks in urban neighborhoods include the swarming social behavior of urban dwellers; the dynamics of their existing communicative ecology; and the serendipitous, voluntary, and place-based quality of interaction between residents on the basis of choice, like-mindedness, mutual interest and support needs. Drawing on an analysis of these factors, the conceptual design framework of a prototype system — the urban tribe incubator — is presented.

Modeling resource management in the building design process by information constraint Petri nets

The effect of resource management on the building design process directly influences the development cycle time and success of construction projects. This paper presents the information constraint net (ICN) to represent the complex information constraint relations among design activities involved in the building design process. An algorithm is developed to transform the information constraints throughout the ICN into a Petri net model. A resource management model is developed using the ICN to simulate and optimize resource allocation in the design process. An example is provided to justify the proposed model through a simulation analysis of the CPN Tools platform in the detailed structural design. The result demonstrates that the proposed approach can obtain the resource management and optimization needed for shortening the development cycle and optimal allocation of resources.

Preliminary insights from a multiple case study on process modelling impact

Process modelling – the design and use of graphical documentations of an organisation’s business processes – is a key method to document and use information about business processes in organisational projects. Still, despite current interest in process modelling, this area of study still faces essential challenges. One of the key unanswered questions concerns the impact of process modelling in organisational practice. Process modelling initiatives call for tangible results in the form of returns on the substantial investments that organisations undertake to achieve improved processes. This study explores the impact of process model use on end-users and its contribution to organisational success. We posit that the use of conceptual models creates impact in organisational process teams. We also report on a set of case studies in which we explore tentative evidence for the development of impact of process model use. The results of this work provide a better understanding of process modelling impact from information practices and also lead to insights into how organisations should conduct process modelling initiatives in order to achieve an optimum return on their investment.

Daylighting performance of subtropical multi-residential towers : simulations tools for design decisions

During an intensive design-led workshop multidisciplinary design teams examined options for a sustainable multi-residential tower on an inner urban site in Brisbane (Australia). The main aim was to demonstrate the key principles of daylight to every habitable room and cross-ventilation to every apartment in the subtropical climate while responding to acceptable yield and price points. The four conceptual design proposals demonstrated a wide range of outcomes, with buildings ranging from 15 to 30 storeys. Daylight Factor (DF), view to the outside, and the avoidance of direct sunlight were the only quantitative and qualitative performance metrics used to implement daylighting to the proposed buildings during the charrette. This paper further assesses the daylighting performance of the four conceptual designs by utilizing Climate-based daylight modeling (CBDM), specifically Daylight Autonomy (DA) and Useful Daylight Illuminance (UDI). Results show that UDI 100-2000lux calculations provide more useful information on the daylighting design than DF. The percentage of the space with a UDI <100-2000lux larger than 50% ranged from 77% to 86% of the time for active occupant behaviour (occupancy from 6am to 6pm). The paper also highlights the architectural features that mostly affect daylighting design in subtropical climates.

Sustainable urban stormwater management : water sensitive urban design perceptions, drivers and barriers

Stormwater has been recognised as one of the main culprits of aquatic ecosystem pollution and as a significant threat to the goal of ecological sustainable development. Water sensitive urban design is one of the key responses to the need to better manage urban stormwater runoff, the objectives of which go beyond rapid and efficient conveyance. Underpinned by the concepts of sustainable urban development, water sensitive urban design has proven to be an efficient and environmentally-friendly approach to urban stormwater management, with the necessary technical know-how and skills already available. However, large-scale implementation of water sensitive urban design is still lacking in Australia due to significant impediments and negative perceptions. Identification of the issues, barriers and drivers that affect sustainability outcomes of urban stormwater management is one of the first steps towards encouraging the wide-scale uptake of water sensitive urban design features which integrate sustainable urban stormwater management. This chapter investigates key water sensitive urban design perceptions, drivers and barriers in order to improve sustainable urban stormwater management efforts.

Preface to special issue on digital human modelling for vehicle design and manufacturing

The automotive industry has been the focus of digital human modeling (DHM) research and application for many years. In the highly competitive marketplace for personal transportation, the desire to improve the customer’s experience has driven extensive research in both the physical and cognitive interaction between the vehicle and its occupants. Human models provide vehicle designers with tools to view and analyze product interactions before the first prototypes are built, potentially improving the design while reducing cost and development time. The focus of DHM research and applications began with prediction and representation of static postures for purposes of driver workstation layout, including assessments of seat adjustment ranges and exterior vision. Now DHMs are used for seat design and assessment of driver reach and ingress/egress. DHMs and related simulation tools are expanding into the cognitive domain, with computational models of perception and motion, and into the dynamic domain with models of physical responses to ride and vibration. Moreover, DHMs are now widely used to analyze the ergonomics of vehicle assembly tasks. In this case, the analysis aims to determine whether workers can be expected to complete the tasks safely and with good quality. This preface provides a review of the literature to provide context for the nine new papers presented in this special issue.

Resilience by design: A participatory approach to designing an interactive digital application for promoting children's resilience

The promotion of resilience (the capacity of an individual or community to bounce back and recover from adversity) has become an important area of public health. In recent years it has expanded into the digital domain, and many online applications have been developed to promote children's resilience. In this study, it is argued that the majority of existing applications are limited because they take a didactic approach, and conceive of interaction as providing navigational choices. Because they simply provide information about resilience or replicate offline, scenario-based strategies, the understanding of resilience they provide is confined to a few, predetermined factors. In this study I propose a new, experiential approach to promoting resilience digitally. I define resilience as an emergent, situated and context-specific phenomenon. Using a Participatory Design model in combination with a salutogenic (strength-based) health methodology, this project has involved approximately 50 children as co-designers and co-researchers over two years. The children have contributed to the design of a new set of interactive resilience tools, which facilitate resilience promotion through dialogic and experiential learning. The major outcomes of this study include a new methodology for developing digital resilience tools, a new set of tools that have been developed and evaluated in collaboration with children and a set of design principles to guide future development. Beyond these initial and tangible outcomes, this study has also established that the benefits of introducing Participatory Design into a health promoting model rests primarily in the change of the role of children from "users" of technology and education to co-designers, where they assume a leadership role in both designing the tools and in directing their resilience learning.

Performing design: game design, practice, praxis and the theatre of the impressed

This paper is a reflection on a design teaching project that endeavours to establish a culture of critical design thinking in a tertiary game design course. In the first instance, the ‘performing design’ project arose as a response to contemporary issues and tensions in the Australian games industry and game design education, in essence, the problem of how to scaffold undergraduate students from their entry point as ‘players’ (the impressed) into becoming designers. The performing design project therefore started as a small-scale intervention to inspire reflection in a wider debate that includes: the potential evolution of the contemporary games industry; the purpose of game design education; and the positioning of game design as a design discipline. Our position is that designing interactive playful works or games is victim of a tendency to simplify the discipline and view it from either the perspective of science or art. In this paper we look at some of the historical discussions on the distinct identity of games. Then we present an overview of the typical state of play in contemporary game design education which inspires the performing design project as an intervention or teaching technique. This leads us to question understandings of education and training and creativity and innovation. Finally we reflect on insights arising from the performing design project which lead us to support Archer’s call for a ‘third area’ that balances the monolithic practices of the two major academic disciplines.

I just want to design a sexy flying car! Teaching design-led innovation to designers

Many international management programs have capitalised on the value design can have upon potential business solutions and strategies (Martin, 2009 & Brown, 2008) as well as many international design programs introducing designers to business theory and curriculum (Manzini & Rizzo, 2011). This paper presents the findings from structured interviews with undergraduate design students and design industry professionals. Current literature surrounding design led innovation and the role designers’ play within it is also discussed and the challenges facing designers in this emerging design era are presented. The findings from this study indicate that most designers enter an undergraduate program not wanting to become the business leaders of tomorrow. Instead, they enter in the hope they can humbly help people and to make a difference in the world. There are contentions with this perspective, felt by industry, academia and students around why designers need to be taught business theory content. This paper provides the first step to overcoming this challenge by providing insight into the attitudes, perceptions and challenges designers are facing with this new design era.

Design Integration Workshops 2012

Businesses will learn how design integration can increase growth and productivity, and gain a sustainable competitive advantage. This hands on two-day workshop will demystify design thinking and introduce you to both theory and practice for the latest, world-class design integration methods. Design integration will transform your business and boost resilience in the face of current global, social and economic challenges.

First year design "Visualisation II": The hybridisation of analogue and digital tools

This paper discusses first year students’ responses and outcomes to the integration of digital technologies in their second semester foundational visualisation class; ‘Visualisation II’. As the second class in the Visualisation series, previous analogue knowledge taught in ‘Visualisation I’ is compounded with new digital technologies establishing the introduction to a myriad of hybrid visualisation tools and techniques for design exploration and design artefact. This research examines the differentiation between analogue and digital design, common precedents of the two, and reflects upon the environment and class structure with the learning experiences and confidence of surveyed participants.

Analyzing the literature for the link between the conservative Islamic culture of Saudi Arabia and the design of sustainable housing

Saudi Arabia experiences housing shortage for mid and low-income families, which is caused by rapid population growth. This condition is worsened by the fact that the current housing supply has problems in meeting both sustainable requirements and cultural needs of those families. This paper aims to investigate the link between the unique conservative Saudi culture and the design of sustainable housing, while keeping the housing cost affordable for mid and low-income families. The paper is based on a review of literatures on the issues of the Islamic culture and how can they be integrated into the design process of a Saudi house. Findings from literature reveiw suggest several design requirements for accommodating the conservative Saudi Culture in low cost sustainable houses. Such requirements include the implementation of proper usage of windows, and house orientation with a courtyard inside rather than facing the main street will provide natural ventilation while maintaining privacy. The main contribution to the body of knowledge is that this is a new approach to sustainable housing in Saudi Arabia considering not only energy use and architectural design issues but also socio-cultural issues as an essential part of sustainability.

Couture Academy Exhibition : a curation of the story behind a couture design

Research background: The general public is predominantly unaware of the complexities and skills involved in the fashion supply chain (design, manufacture and retail) of couture/bespoke garments. As cited in McMahon and Morley (2011) “While a high price tag is widely accepted as a necessary element of luxury products (Fionda &Moore, 2009) this must be accompanied by a story that gives the items intrinsic as well as extrinsic value (Keller, 2009). Research question: Is it possible to simulate a fashion couture studio environment in a non-traditional public space in order to produce and promote the processes involved in couture designs; each with their own story and aligned to the aesthetic of six collaborating high profile couture fashion retailers? Research contribution: The Couture Academy project allowed the team to curate the story behind the couture design and supply chain process. It was an experimental, curated, ‘hot-house’ fashion design project undertaken in real time to create one-off couture garments, inspired by key seasonal fashion trends as determined by leading Westfield retailers. The project was industry based, with Westfield Chermside as the launch pad for six QUT fashion students to experiment with design nuances aligned to renowned national fashion industry retailers; Cue, Dissh, Kitten D'Amour, Mombasa and Pink Mint. Industry mentors were assigned to each student designer, in order to heighten the design challenge. The exhibition consisted of a pop-up couture workshop based at Westfield Chermside. A complete fashion studio (sewing machines, pattern-cutting tables and mannequins) was set up for a seven day period in the foyer of the shopping centre with the public watching as the design process unfolded in real-time. The final design outcomes were paraded at the Southbank Precinct to a prominent industry and media panel, with the winner receiving a $2000 prize to fund a research trip to an international fashion capital of their choice. Research significance: This curated fashion project was funded by Westfield Group Australia. "It was the most successful season launch Westfield Chermside has ever had from both an average volume for exposure perspective, and in terms of the level of engagement with retailers and shoppers," said Laura Walls, Westfield Public Relations Consultant. Significant media coverage was generated; including three full pages of editorial in Brisbane’s Sunday Mail, with an estimated publicity value of $95,000. And public exposure through the live project/exhibition was estimated at 7,000 people over the 7 days.