No description available.

The influent to a water and resource recovery facility (WRRF) generally exhibits significant diurnal variations in flow rate and load concentration. This makes determining the operating parameters and subsequently the overall operation of plants difficult, especially in developing countries due to the lack of highly skilled operators. Hence, there is an incentive for the control and operation of WRRFs in developing countries to be improved. Flow equalization tanks were identified as a potential method to attenuate the diurnal variations in flow rate and load concentration into plants. The main aim of this research was to develop a viable dynamic simulation model for the operation of flow equalization tanks, within a plant-wide framework (to allow for the evaluation of design and control strategies). The next aim was to determine the benefits of equalization tanks towards design and optimised operation of future WRRFs via scenario analyses. Finally, the effects of the equalization tank on the performance of various unit processes in a WRRF were to be investigated. The model was developed in three steps; i) the development of the required equations to model equalization tanks, ii) mass balance throughout the model for internal consistency and iii) scenario analyses to determine if the model generated reasonable and scientifically sound outputs. The model was developed using Microsoft Excel Visual Basic (VBA) and WEST®. Two scenarios were considered to assess the equalization tank modelled. Scenario One involved the comparison of the capital cost, unit process sizes and total footprint of a balanced sludge age Modified Ludzack-Ettinger (MLE) system with and without an equalization tank. Scenario Two compared the plant performance of the MLE system designed in Scenario One with and without a flow equalization tank. A dynamic simulation model replicating equalization tanks was successfully developed. From scenario analyses, it was determined that using an MLE system and only considering equalization of flow, there was a reduction in the size of several unit processes by 8-9% (primary settling tank, biological reactors, secondary settling tank, flotation unit, anoxic-aerobic digester), due to the less conservative design values that could be used as the variations of the influent were decreased. Despite this, a 13% overall increase in the footprint of the WRRF was observed due to the addition of the equalization tank. The attenuation of diurnal flow variations also resulted in reduction of various plant parameters by up to 50% (flow, OUR, VSS flux). Finally, there was a 10% improvement in the performance of various unit processes due to the presence of the equalization tank. In conclusion, the inclusion of equalization tanks in WRRFs has significant positive effects. These results were obtained with equalization of flow only. Some other limitations were experienced during the project resulting in the following recommendations: further research will be needed to validate and calibrate the model, As the model was not successfully incorporated in a plant-wide framework, further developments in that direction are required, as well as including the equalization of load in the model.

Following large rain events, extraneous freshwater contributions known as inflow and infiltration (I/I) bypass the storm sewer and enter the sanitary sewer system. In areas with a high water table, like Pinellas County and the surrounding Tampa Bay area, a majority of the wastewater infrastructure is submerged year round exacerbating the rate of groundwater infiltration. This excess flow overloads the existing wastewater infrastructure leading to sanitary sewer overflows (SSOs). These SSOs result in serious problems for municipalities and utilities across the country. This study was performed in order to assist Pinellas County Utilities in rehabilitating their southern sewer system. To do this, 59 sub-basins across 8 sewer zones were monitored through Pinellas County’s Phase 1 Flow Monitoring Program accounting for over 150 miles of gravity pipe. For each sub-basin, a flow meter was utilized to measure the flow from May to October, 2017. This data was analyzed to separately quantify the amount of infiltration and inflow in each sub-basin, respectively. Once quantified, a Severity Index (SI) was developed in order to give each sub-basin a score from 1-100 as it relates to the condition of the gravity mains in the sub-basin. The SI was a function of locational features available with the use of a Geographic Information System (GIS), such as the distance to water bodies and the soil hydrologic group (SHG), as well as intrinsic pipe properties including the type of pipe material and the age of pipe. Once validated with additional flow monitoring data, the developed SI framework can serve as an additional tool utilized by Pinellas County Utilities to identify areas in need of sanitary sewer rehabilitation. Being that the model only requires easily attainable information, this approach is less time consuming and is inexpensive as compared to traditional flow monitoring efforts. The study also examined the required monetary investment by Pinellas County Utilities in order to abate the 17 sub-basins observed in the study with an infiltration rate greater than the marginal threshold put forth by the Environmental Protection Agency (EPA). The study indicated that gravity pipe rehabilitation does not make a significant impact on groundwater infiltration until at least 30% of the gravity pipes in the sub-basin are lined. This is due to the groundwater table submerging a majority of the wastewater infrastructure. Once this threshold is met, lining was observed to abate groundwater infiltration linearly. The results found that $4.4 million will be required to rehabilitate the affected sub-basins to a marginal rate of infiltration and reduce the flow to South Cross Bayou Water Reclamation Facility (SCBWRF) by an average of 0.72 mgd (million gallons per day). On an annual basis, this reduction in flow will result in approximately $650,000 in treatment costs savings.

Släckvatten är den biprodukt som blir kvar efter att en brand är släckt och innehåller många olika föreningar som är skadliga för miljö och hälsa. Till exempel kan ett utsläpp av släckvattenslå ut en vattentäkt som tar många år och kostar många miljoner att återställa, om det ens går. Vissa av föroreningarna kan även stanna i organismer genom hela näringskedjan. Ett bättre handhavande av släckvatten skulle med andra ord kunna leda till stora ekonomiska och miljömässiga vinster. Syftet med denna rapport är att undersöka hur svensk släckvattenshantering kan utformas. Rapporten undersöker hur organisation, utbildning, rutiner, teknisk förmåga, förmågan att rena släckvattnet kan se ut runt en släckvattenresurs hos svenska räddningstjänster. Dessutom undersöker rapporten om det finns behov av stöttning från en annan aktör när det gäller släckvattenshanteringen. Rapporten berör endast hantering av släckvatten på skadeplatsen. Metoden som valdes för rapporten är fallstudie, där det ingick en litteraturstudie samt en intervjustudie. Tre organisationer valdes ut för intervjuerna: Södra Älvsborgs Räddningstjänstförbund, Eskilstuna Räddningstjänst, Myndigheten för samhällsskydd och beredskap (MSB). Resultatet visar att de två räddningstjänsternas släckvattenresurser liknar varandra i alla de områden som rapporten berör. Det framkom även att MSB påbörjat ett arbete för att utveckla släckvattenshanteringen med riktlinjer och vägledningar. De slutsatser som kan dras av resultatet är att organisationen runt en släckvattenresurs bland annat är att resursen inte ingår i någon larmplan utan larmas ut separat av RL. Resursen har placerats på en RIB- eller värnstation för att sprida kompetensen i organisationen samt så att resursen inte ska störa styrkeuppbyggnaden för andra stationer. Resursen har eget befäl och mellan 3–4 brandmän. Det finns samarbete mellan kommuner/förbund både ekonomiskt och operativt för de undersökta släckvattenresurserna. När det gäller utbildning för dem som arbetar med släckvattenresursen hålls årliga helgövningar plus ytterligare 3h utöver det hos Eskilstuna och hos SÄRF övas materialkännedom kontinuerligt. Befälen som arbetar med resursen har ingen påbyggnadsutbildning om vilka föroreningar som finns i vattnet utan ska kunna bedöma släckvattnets farlighet utifrån vad som har blivit släckt. Alla insatser utvärderas av personalen som varit på insatsen som sedan berättar för dem som inte varit med. Det är enligt respondenterna svårt att samla upp släckvatten då förutsättningarna kan se olika ut på olika insatser. Detta gör att det inte går att ha några förbestämda rutiner, checklistor eller lathundar. En taktik som dock finns är att leda vattnet mot en svacka eller dagvattenbrunn som förses med en pumpgrop för att sedan pumpa vattnet till en bassäng eller ett uppsamlingskar. Det finns rutiner för bränder på vattenskyddsområde som bygger på försiktighetsprincipen. De rutiner som finns för uppsamling inomhus är att brunnar i industrilokaler täpps till. Uppsamlingen påbörjas oftast efter att livräddande insats är klar och uppsamlandet sker mellan kall och varm skyddszon. Den tekniska förmågan för släckvattenhantering i basbilarna, där släckande styrka åker, är begränsad och förväntningen är att kunna samla upp genom att täta dagvattenbrunnar och lägga ut fylld grovslang som barriär. Fordonet som de undersökta släckvattenresurserna baseras på är en pick-up med släp. Släpet får max väga 750kg för att undvika krav på utökad körkortsbehörighet. Personalen bär larmställ, hjälm, stövlar med stålhätta, gummihandskar, skyddsglasögon och har även tillgång till tryckluftsapparat. Hanteringen av kontaminerad utrustning följer Skellefteåmodellen för friska brandmän. Utrustningen på resursen består främst av: brunnsmattor och brunnstätningar, självresande kar, dränkbara pumpar, spillbarriärer, vattendammsugare, pumpgrop och bärbara elverk. Uppsamlingsförmågan varierar mellan 10 – 26 m3 vilka gör att uthålligheten för uppsamlingen varierar mellan 20 minuter och 2,5 timmar beroende hur många av pumparna som används. Förmågan för rening är i dagsläget lika med noll och det beror mycket på att räddningstjänsterna inte har råd med reningsverk. Stöttning från MSB efterfrågas främst kring det otydliga juridiska ansvaret för släckvatten samt metodutveckling. Sedan efterfrågas stöttning rent operativt när det gäller rening och provtagning av släckvatten. Det kan antingen komma från MSB men kan också komma från samarbete mellan räddningstjänster/förbund eller med andra kommunala verksamheter så som miljö- och servicekontor eller VA. / Extinguishing water is the by-product remains after a fire has been extinguished. It contains many different compounds that could harm the environment and health. A spill of extinguishing water could e.g. destroy a water source that might take many years and costs many millions to restore, if even possible. Some of the pollutants can also stay in organisms throughout the food chain. In other words, better management of extinguishing water could lead to major economic and environmental benefits. The purpose of this report is to investigate how Swedish extinguishing water management can be designed. The report examines how organization, training, routines, technical ability, the ability to purify the fire water can be done around a fire water resource at Swedish rescue services. In addition, the report examines whether there is a need for support from another actor in terms of fire water management. The report only concerns the handling of extinguishing water at the accident site. The method chosen for the report is a case study, which included a literature study and an interview study. Three organizations were selected for the interviews: South Älvsborgs Rescue Services Association, Eskilstuna rescue service and the Swedish Civil Contingencies Agency. The results show that the two examined extinguishing water resources are very similar in all the areas covered by the report. It also emerged that MSB has begun work to develop guidelines for extinguishing water management. The conclusions that can be drawn from the result are that the organization around an extinguishing water resource is, e.g., that the investigated resources are not included in any alarm plan but is alerted by RL. The resource has been placed at a RIB or part time station to spread the competence in the organization and so that the resource does not interfere with force building for other stations. The resource has its own commander and between 3-4 firefighters. For both investigated resources, there is cooperation between several fire departments both financially and operationally for the extinguishing water resource. When it comes to training for those who work with the fire water resource, annual weekend exercises are held plus an additional 3 hours per year. Knowledge of how to use the equipment is practiced continuously. The commanders who work with the resource have no additional training in what contaminants that could be expected to be present in the water but must be able to assess the danger of the extinguishing water based on what has been extinguished. All rescue efforts are evaluated by the staff who have been on the rescue, who then tell those who have not participated. According to the respondents, it is difficult to collect extinguishing water as the conditions vary a lot for different rescue efforts. This means that it is not possible to have any pre-determined routines, checklists or guides. One tactic that exists, however, is to direct the water towards a depression or stormwater well provided with collection vessel and then pump the water to a pool or a collection tank. There are routines for fires within water protection areas that are based on the precautionary principle. The routines that exist for indoors collection are that wells in industrial premises are being clogged. The collection usually starts after the life-saving operation has been completed and the collection takes place between a cold and a warm protection zone. The technical ability for extinguishing water management in the base cars is limited and the expectation is to be able to collect by sealing stormwater wells and laying out filled coarse hose as a barrier. The vehicle on which the fire water resource is based is a pick-up with a trailer. A trailer that may weigh a maximum of 750 kg as then no extended driving license is required. The staff wears alarm racks, helmets, boots with steel caps, rubber gloves, goggles, and also has access to a compressed air device and the handling of contaminated equipment follows the “Skellefteå model” for healthy fire fighters. The equipment on the resource mainly consists of well mats and well seals, self-erecting tubs, submersible pumps, spill barriers, water vacuum cleaners, pump pits and portable power plants. The collection capacity varies between 10 - 26 m3 which means that the endurance for the collection is between 20 minutes and 2.5 hours depending on how many of the pumps that are being used. Today, the capacity for treatment of the extinguishing water is equal to zero, largely since the rescue services cannot afford mobile treatment plants. Support from MSB is requested regarding the unclear legal responsibility of the extinguishing water, as well as for method development. Also operational support is asked for, in terms of treatment and sampling of the extinguishing water. Such support could either come from MSB but also from cooperation between rescue services or with other municipal activities such as environmental and service departments or water and wastewater departments.

Human watershed activities such as converting land cover to agriculture and livestock grazing have negatively impacted stream water quality worldwide. One such case is Utah’s Upper Sevier River where a loss of woody bank vegetation (reduced shading) and accelerated bank erosion (increased fine sediment inputs) has led to increased stream temperature and water turbidity. As a result, the state of Utah sought to improve water quality conditions using streambank restoration. While commonly recommended and performed, the effectiveness of this sort of restoration has rarely been quantified. Here, I evaluated a restored reach of the Upper Sevier River near Hatch, UT using continuous monitoring data and a historical photo analysis. As Utah wishes to continue performing this type of restoration in additional locations on the Upper Sevier River, I applied a simple sediment budget model to test its value in informing future streambank restoration decisions. Continuous monitoring data at the upstream and downstream extent of restoration showed that both stream temperature and turbidity increased downstream along the restored reach. In addition, I found that stream temperature violated Utah’s cold-water stream threshold at both sites but did not violate thresholds for rainbow trout. Turbidity violated state and biological thresholds at both sites. I was unable to conclude whether the streambank restoration directly altered water quality because I lacked monitoring data before restoration occurred. Results of the historical aerial photo analysis showed that restoration practitioners were successful in reducing cut bank erosion. My use of SIAM as a simple sediment budget model proved insufficient due to poor data quality and quantity. Overall, streambank restoration was successful at reducing cut bank erosion, and I recommended monitoring future restoration before and after project completion, identifying and monitoring upstream sources of fine sediment, and pursuing more comprehensive sediment models to inform future streambank restoration.

Purpose: The aim of this research is firstly to find out whether or not companies have strategies to address future scenarios of water scarcity. It is of importance to find out what they are doing to mitigate the issues they already have or will encounter in the future. Secondly, motivational drivers who have affected their decision-making are discussed in order to fully understand the process of working with water scarcity. Method: The qualitative research paper is based on five in-depth interviews with open-ended questions. The interviewee was able to explain the processes and strategic decision-making of the company. Follow-up questions were sent via email to complement these. Findings: The study declares that the majority of the companies had vague strategies to minimize water consumption and mitigate the issues they would encounter in a situation of water scarcity. They were more like visions or intentions. The motivational drivers and pressures companies have encountered and which have initiated the process and developing strategies were primarily the four following: (1) economic, (2) environmental, (3) social, and (4) impact from authorities.

No description available.

Water is essential element for human survival but unstainable development practices and short term economic benefits are responsible for water scarcity in many areas around the world. Climate change is aggravating the risk with distribution and water availability. Agriculture is a sector highly dependent on water. The livelihood of a vast population in the world depends on not only agriculture, but also forestry, wetlands and fisheries and land use which, in turn, are strongly influenced by water based ecosystems that depend on monsoon rains. India is a global agricultural powerhouse. It is the world’s largest producer of milk, pulses, and spices as well as the largest area under wheat, rice and cotton. But increasing water scarcity in India is affecting agricultural sector, hence affecting socio- economic conditions of poor Indian farmers. In some pockets of the country, attempts have been made during the last few decades to manage the scarce water resources more efficiently and govern them more wisely, so that agriculture as the main economic backbone of the local communities can be sustainably supported. Ralegan Siddhi is one such outstanding case where the rainwater harvested through local interventions has enabled sustainable development of the entire community. The village stands out as an oasis in the desert. The aim of the study is to understand how water has been governed in Ralegan Siddhi to enable sustainable agriculture and hence sustainable development of the community. Ultimately, the study is foreseen to help improve the farmers’ situation in water scarce areas in India and elsewhere by sharing this study report based on Ralegan Siddhi’s water governance practices with other researchers as well as concerned agencies and actors.

Wetlands are considered a last line of defence against poor water quality. Despite the natural capabilities of wetlands to remove a variety of contaminants from surface water, the track record for wetland conservation leaves much to be desired. In the northern parts of the City of Tshwane, 84% of wetlands have been degraded. When viewed against the poor bacteriological quality of river water in the study area, the lack of wetland conservation efforts is of particular concern. Given the large number of wetlands in the Tshwane area in need of rehabilitation, this study aimed to devise a methodology to prioritise these wetlands for rehabilitation. No blueprint for such a prioritisation process exists, as studies are adapted to take into account the availability of data and the unique requirements of the study area. The methodology for this study is based on the prioritisation of a specific river basin, based on expected maximum faecal bacterial load originating from various sources of pollution. Four river basins were compared with each other in a series of screening processes. Screening was done on a landscape level using a Geographic Information System (GIS) to generate various composite layers as part of the screening process. The screening processes relied on the application of several weighted criteria. Weights for criteria are based on scientific literature. Weights are also allocated in line with the “worst case scenario”, as the study is in essence an assessment of the various pollution sources and their maximum possible contribution to deteriorating surface water quality. A Simple Additive Weighting technique was used to assess the total pollution loads and total numbers of users at risk from contaminated surface water in each of the river basins. It is important to note that the objective is to only rate the pollution sources, whilst exact pollution loads were not calculated. Diffuse, areal and point sources of pollution were rated using the estimated contributions to faecal coliform loads. The river basin with the highest score was selected for the selection of candidate wetlands for rehabilitation purposes. The Apies River Basin scored highest for most of the criteria, with the exception of the number of households at risk from contaminated surface water. Despite the 0.60 weight allocated to households at risk, the extent of pollution sources in this river basin allowed it to be singled out as the basin in which a wetland for rehabilitation is most urgent in order to attenuate bacterial load. Two wetlands were short listed, based on their high need for rehabilitation, their hydrogeomorphic location (valley bottom with a channel), and given that they are larger than 1ha in size and within a minimum distance from the households at risk. Site level assessments are required for a final selection between the two, taking into account the nature of the current disturbances, the possibility of risk due to back-flooding, the projected costs associated with rehabilitation, the nature of the vegetation associated with the wetlands and the general conservation value of each of the wetlands.

This thesis identifies impacts of behaviors and technology on residential indoor water use and conservation efforts. We use pre-existing detailed end-use data collected before and after toilets, faucets, showerheads, and clothes washers were retrofitted in 96 owner-occupied, single-family households in Oakland, California; Seattle, Washington; and Tampa, Florida between 2000 and 2003. Water volume, duration of use, and time of use were recorded and disaggregated by appliance for two weeks before and four weeks after appliances were retrofitted. For each appliance, we compare observed differences in water use before and after retrofits to water savings predicted by analytical engineering, semi-analytical engineering, and econometric regression methods. Results show that observed and predicted distributions of water savings are skewed with a small number of households showing potential to save more water. Results also show the relative and significant influence on water saved of both technological (flow rates of appliances) and behavioral (length of use, frequency of use) factors. Additionally, the number of residents, and the performance and the frequency of use of the appliance are the key factors that distinguish households that save the most water from households that save less. Study results help improve engineering methods to estimate water savings from retrofits and allow water utilities to better target subcategories of households that have potential to save more water.