Laboratory Studies on Granular Filters and Their Relationship to Geotextiles for Stormwater Pollutant Reduction

Applications of geotextiles within tertiary stormwater treatment systems and for stormwater infiltration can provide a substrate for biofilm formation, enabling biological treatment of contaminants. Geotextiles can serve as an efficient part of stormwater filtration within the urban water environment. The project assessed the applications of three experimental granular filters as a sustainable urban drainage system (SUDS) for the decomposition of organic pollutant loading present in stormwater. The three filter rigs were packed with alternating layers of filter media consisting of gravel, pea gravel, sand and either a single, double or no layer of geotextile membrane. A nonwoven geotextile was layered within the filter media. The hydraulic loading capacity for the three filters matched that commonly used with conventional sand filters systems. Water quality parameters were quantified by measuring suspended solids, chemical oxygen demand, dissolved oxygen, pH, nitrate-nitrogen, and phosphate concentrations. It was found that Filter Rig No. 3 (upper and lower geotextile membrane) and Filter Rig No. 2 (single geotextile membrane) had a significant statistical difference in treatment performance from Filter Rig No. 1 (no geotextile membrane)

Bridge Deck Runoff: Water Quality Analysis and BMP Effectiveness

INE/AUTC 10.0

Source control SUDS delivery on a global scale and in Scotland including approach by responsible organisations and professional groups

Background to researchThe Sustainable Urban Drainage Scottish Working Party via CREW commissioned this work on the implementation of source control for SUDS in Scotland. The project is being carried out by researchers based at Abertay University Dundee involves three phases. These are presented in separate reports; this report covers phase 2 of that work. Source control sustainable urban drainage systems (SUDS) are an established technique in many parts of the world. Source control SUDS are a key component of what is termed the stormwater treatment train. Source controls manage the more frequent but smaller polluting rainfall events as close to the source as possible (where the rain falls). Site and regional control SUDS are larger downstream structures which manage the longer term rainfall events and provide additional treatment when required. One of the key advantages of managing the more frequent rainfall events at source is that downstream site and regional SUDS will have longer life spans resulting in overall cost efficiencies. Scotland is regarded as a frontrunner in the UK regarding implementation of SUDS with site and regional drainage structures now considered ‘business as usual’. However the uptake of source control is less routine than would be expected.Objectives of researchPhase one of this research looked at the background to the evolution of source control in Scotland to provide an insight into the enabling factors and obstacles for uptake of the systems since. Phase two(this report) appraises delivery of the systems in seven countries and case studies are developed to understand why source control was implemented and how it was achieved. The current delivery by responsible organisations and professional groups which encourage and influence the source control agenda in Scotland is also appraised. Using these findings, the transition pathway from traditional drainage to source control SUDS are reconstructed and mapped out to highlight the historical and current enabling (and disabling) factors to realise the transition to date. A transition framework is used to highlight the transition strengths developed by responsible organisations over the last two decades which had assisted in accelerating the transition.Key findings and recommendationsKey outcomes of this research include:* In Scotland the source control vision and agenda is fragmented due to different stakeholder drivers and funding mechanisms.* There are examples of the use of incentives in Scotland (i.e. legislative, regulatory, financial,social and environmental) to drive integrated agendas. However these have not been successfully showcased to provide the evidence base for encouraging replication and up-scaling of the methodologies and techniques.* There are limited frontier source control SUDS ‘niches’ to nurture innovative techniques such as raingardens – a learning by doing concept. A more focused research agenda to validate these systems as viable sustainable solutions for Scotland would assist in accelerating uptake.* Lack of sector engagement, particularly with the public is a disabling factor for uptake.A final observation from this phase of the study is that requests from various interested parties for CREW / SUDS Working Party to share outputs indicates the need for this research

District plan implementation under the RMA: Confessions of a resource consent

This report focuses on results from Phase 2 of PUCM - the quality of plan implementation in six district councils selected for their range of plan quality and capacity to plan. Only those results considered to be important for assisting the six councils (and others) to improve implementation of their plans are included in this report. The findings and recommendations, both specific and general, ought to be instructive for other councils, thereby helping to improve their plans and implementation processes. Since hapu/iwi interests formed a key component of the research, the outcomes will help enhance their case for better consideration of their interests when dealing with local government. As well, many of the findings and recommendations relate to matters of governance and capacity building that require Government action, which until done will make it difficult for councils to achieve quality plans and implementation processes

Town of Chester Stormwater Management Project

Great Bay Environmental Consulting (GBEC) worked with the Town of Chester Planning Board to improve regulatory approaches to stormwater management. The project was conducted in two phases: Phase I involved an inventory and assessment of existing regulations for their treatment of stormwater management, with recommendations for an approach to improve stormwater management in the town. The Planning Board opted to focus on specific changes to existing subdivision and site planning regulations, so Phase II of the project involved the development of specific recommendations for those regulations