Comment letters to the National Commission on Commission on Fraudulent Financial Reporting, 1987 (Treadway Commission) Vol. 2

https://egrove.olemiss.edu/aicpa_sop/1662/thumbnail.jp

Selecting an economically suitable and sustainable solution for a renewable energy-powered water desalination system: A rural Australian case study

Renewable energy (RE) powered reverse osmosis (RO) desalination is rapidly evolving as an attractive energy-water nexus solution that combines the sustainability of RE and the maturity of RO. The intermittent and fluctuating power of RE, the variable operation of RO systems and the social acceptance of RO, commonly perceived as an energy intensive process, are some of the challenges currently faced by scientists and decision makers. The objective of this study is to identify an energy-water system that is cost-effective, sustainable and socially accepted in a rural community of Australia. The numerical analysis is based on one year (2016) data of energy demand of the community. The size and energy demand of the RO plant is assumed based on the 2016 water demand. A modelling approach that can be readily available and simple to use by the regional energy and water utilities is developed. Out of the seven assessed energy configurations, the most cost-effective system includes a hybrid RE-RO system characterized by grid electricity, a 2.4 MW wind and a 2.8 MW distributed rooftop solar photovoltaic (RTPV) system to supply the 14 GWh and 1.2 GWh annual energy demand of the community and RO plant, respectively. A system of RTPVs distributed across the community is suggested as an option to improve the social acceptance of the RO by directly engaging the consumers in the supply of their own energy and water needs. The RO is simulated to operate as a deferrable electrical load, whose feed flow rate and operating pressure vary (within admissible limits) as a function of the renewable energy excess and the end-user's energy consumption. The proposed energy-water system aims to provide a sustainable and economical solution whilst targeting the cultural gap between community members and decision makers that has been hindering desalination projects in Australia's rural communities

Characterising stormwater gross pollutants captured in catch basin inserts.

The accumulation of wash-off solid waste, termed gross pollutants (GPs), in drainage systems has become a major constraint for best management practices (BMPs) of stormwater. GPs should be captured at source before the material clogs the drainage network, seals the infiltration capacity of side entry pits or affects the aquatic life in receiving waters. BMPs intended to reduce stormwater pollutants include oil and grit separators, grassed swales, vegetated filter strips, retention ponds, and catch basin inserts (CBIs) are used to remove GP at the source and have no extra land use requirement because they are typically mounted within a catch basin (e.g. side entry pits; grate or gully pits). In this study, a new type of CBI, recently developed by Urban Stormwater Technologies (UST) was studied for its performance at a site in Gosnells, Western Australia. This new type of CBI can capture pollutants down to particle sizes of 150µm while retaining its shape and pollutant capturing capacity for at least 1year. Data on GP and associated water samples were collected during monthly servicing of CBIs for one year. The main component of GPs was found to be vegetation (93%): its accumulation showed a strong relationship (r(2)=0.9) with rainfall especially during the wet season. The average accumulation of total GP load for each CBI was 384kg/ha/yr (dry mass) with the GP moisture content ranging from 24 to 52.5%. Analysis of grain sizes of GPs captured in each CBI showed similar distributions in the different CBIs. The loading rate coefficient (K) calculated from runoff and GP load showed higher K-values for CBI located near trees. The UST developed CBI in this study showed higher potential to capture GPs down to 150µm in diameter than similar CBI devices described in previous studies