Since humans began to permanently settle locations for extended periods of time there has been the challenge to safely dispose of, or treat human effluent. In specific to the communities of Nunavut and Arctic Canada, the treatment of wastewater has been particularly challenging. The harsh climate, remote nature and socio-economic factors are a few of the aspects which make the treatment of wastewater problematic in Canadian Arctic communities. In the past several decades a number of conventional and alternative wastewater treatment systems (e.g. lagoons and tundra wetlands) have been proposed and implemented in Nunavut and other remote Arctic communities. Knowledge of performance of these systems is limited, as little research has been conducted and regulatory monitoring has been poorly documented or not observed at all. Also, in the past, the rational design process of treatment systems in Arctic communities has not acknowledged cultural and socio-economic aspects, which are important for the long-term management and performance of the treatment facilities in Arctic communities. From 2008 to 2010 I characterized and studied the performance of several tundra wastewater treatment wetlands in the Kivalliq Region of Nunavut, as well as two in the Inuvaliat Region of the Northwest Territories. Performance testing occurred weekly throughout the summer of 2008. Characterization included surveys of plant communities in the tundra wetlands, specifically analyzing the relationship between Carex aquatilis and various nutrient contaminants in wastewater. Through their characterization I was able to provide greater insight into primary treatment zones within the wetland, and identify the main potential mechanisms for the treatment wastewater in the Arctic. I also studied the performance of a horizontal subsurface flow (HSSF) constructed wetland in Baker Lake Nunavut; the first system of its kind in the Canadian Arctic. The weekly performance study showed average weekly percent reduction in all parameters, with small deviations immediately after snow-melt and at the beginning of freeze-up. For the six parameters monitored I observed reductions of 47-94% cBOD5, 57-96% COD, 39-98% TSS, >99% TC, >99% E. coli, 84-99% NH3-Nand 80-99% TP for the six tundra treatment wetlands. Whereas, the wetland characterization study through the use of spatial interpolations on each of the wetlands and their water quality showed that concentrations of the wastewater parameters decreased the most in the first 100m of the wetland in all three treatment wetlands used in this portion of the analysis (Chesterfield Inlet, Paulatuk and Ulukhaktok). Areas of greatest concentration where shown to follow preferential flow paths with concentrations decreasing in a latitudinal and longitudinal direction away from the wastewater source. The Paulatuk and Ulukhaktok treatment wetlands were observed to effectively polish pre-treated wastewater from the facultative lake and engineered lagoon, with removals of key wastewater constituents of cBOD5, TSS and NH3-N to near background concentrations. And despite the absence of pre-treatment in Chesterfield Inlet, the wetland was also observed to effectively treat wastewater to near background concentrations. Further characterization on the composition of the sedge C. aquatilis, showed a high percent cover of the species corresponded with areas of high concentration of NH3-N in the wastewater. A principal components analysis verified the spatial results showing correlation between C. aquatilis cover and NH3-N concentrations. Analysis also showed strong positive relationship between sites closer to the source of wastewater and C. aquatilis. No correlation was found between the other parameters analyzed and C. aquatilis. The first year of study of the HSSF constructed wetland showed promising mean removals in cBOD5, COD, TSS, E. coli, Total Coliforms, and TP throughout the summer of 2009; removals of 25%, 31%, 52%, 99.3%, 99.3%, and 5% were observed respectively. However, the second year of study in 2010 the system did not perform as expected, and concentrations of effluent actually increased. I concluded that a high organic loading during the first year of study saturated the system with organics. Finally, a review of planning process and regulatory measures for wastewater in Arctic communities and the impending municipal wastewater standards effluent resulted in the following recommendations; i) wastewater effluent standards should reflect the diverse arctic climate, and socio-economic environment of the northern communities, ii) effluent standards should be region or even community specific in the Arctic, and iii) for planning and management of wastewater incorporation of Inuit understanding of planning and consultation needs to be incorporated in the future. This research has several major implications for wastewater treatment and planning for Nunavut and other Arctic Regions. The performance and characterization of tundra treatment wetlands fills significant gaps in our understanding of their performance and potential mechanisms of treatment, and treatment period in the Kivalliq Region. Although the HSSF constructed wetland failed, further research into engineered/augmented treatment wetlands should be considered as they provide low-cost low maintenance solutions for remote communities. Finally, the data collected in this study will provide significant insight into the development of new municipal wastewater effluent standards for northern communities, which will be reflected in the Fisheries Act.

Stormwater runoff generated from urban areas can be a source of contamination and may negatively impact receiving waters. Best management practices, including the use of treatment wetlands, are recommended to minimize impacts and maintain the quality of water bodies receiving stormwater discharge. This study focuses on the viability of a natural wetland in the treatment of urban runoff. Kuhn Marsh is a natural urban wetland located in Dartmouth, NS. The wetland is approximately 2 ha in size and the primary inlet is a stormwater outfall servicing a 28 ha urban drainage area. Kuhn Marsh has been receiving stormwater generated from the urban drainage area for decades. A wetland drainage area of approximately 9 ha contributes to surface runoff downstream of the wetland inlet. Project objectives are defined as: (i) characterization of the hydrology and hydraulics of the wetland system, (ii) characterization of contaminant fluxes within the wetland system, and (iii) analysis of the treatment performance of Kuhn Marsh. Research strategies used to achieve project objectives include physical and hydrologic characterization of the wetland and contributing watersheds as well as surface and ground water quality analysis. Monitoring was conducted in the wetland during both baseflow and stormflow conditions from May 2011 through October 2012, with the exception of November 2011 to January 2012. Surface water samples were analyzed in the laboratory for TSS, TOC, TN, TP, turbidity, E.coli, and a suite of heavy metals including Fe, Pb, Cu, Cd and Zn. In-situ surface water monitoring included DO, temperature, conductivity and pH. Groundwater samples were analyzed for E.coli and microbial source tracking was performed on all well samples in addition to samples from the inlet and outlet of the wetland. Results from the well samples and the wetland outlet were inconclusive, however the wetland inlet showed human source bacteria indicating potential sewer cross connections within the stormwater system. It was determined that the wetland is an area of groundwater discharge, with groundwater accounting for an average of 50% of the volume discharging through the outlet control structure. Largely due to groundwater influence, Kuhn Marsh shows no peak flow dampening or volume reduction between inlet and outlet. Minimal hydraulic retention times, between 2 and 4 hours, were calculated during stormflow conditions, indicating potential short circuiting of flows through the wetland. Wetland treatment performance was analyzed on a concentration and mass reduction basis and on the number samples that exceeded parameter guidelines at the outlet of the wetland. Guideline exceedances were reported for the majority of samples taken and increases in concentration between inlet and outlet resulted in a larger number of samples exceeding guidelines at the outlet. Despite dilution from groundwater discharge, minimal to no concentration reduction was reported between the inlet and outlet of the wetland. Mass reduction did not occur between the inlet and outlet and Kuhn Marsh was found to be a source of all contaminants sampled. Results of this study show that Kuhn Marsh is no longer acting as a reservoir for stormwater contaminants and, based on the fact that the wetland has been receiving stormwater input on the order of decades, study results may be indicative of the long-term treatment capacity of a stormwater treatment wetland. In the future, comprehensive sampling of groundwater is recommended to determine if contaminants are entering the wetland via groundwater discharge, and if possible, surface water sampling should be conducted on a finer scale to better estimate mass fluxes and contaminant loading rates.

This comparative study explores the mechanisms of pollutant removal efficiency in cold-climate constructed wetlands (CWs) and investigates the benefits, standing and practicability of using these systems to treat wastewater in Canada and Northern China. Treatment efficiencies defined by the Canadian and Northern China experience vary considerably. Experience in both countries shows that the majority of effluent values are generally better than that required by discharge standards in Canada and China. A review of the available case studies on cold weather treatment in both countries indicates that this technology is feasible in Canada and Northern China, although further monitoring data are needed to optimize CW design and ensure that the effluent quality standards are consistently met. In both of these countries and around the globe, increasingly strict water quality standards and the growing application of treatment wetlands for wastewater treatment is an important motive for the development of better numerical models as predictive process design tools. An investigation of the SubWet 2.0 model, a horizontal subsurface flow modeling program used to predict the level of treatment that can be expected was conducted. It has been shown that SubWet can consider the influence of several factors at one time, where empirical equations are generally not able to consider more than two factors at one time and usually in isolation of the other influential parameters. Three different data sets, two from natural wetlands from the Canadian Arctic and one from a CW in Africa were used to illustrate how SubWet can be calibrated to specific wetlands. Compared to other models, it is suggested that SubWet provides one of the best modeling options available for natural tundra wetlands. Further calibration of SubWet with twelve municipal treatment wetlands in the Canadian Arctic clearly demonstrated its ability to model treatment performance within natural tundra wetlands and thus provide an additional predictive tool to aid northern stakeholders in the treatment of municipal effluents. It is anticipated that increased monitoring and the generation of additional measured data will help to better identify the level of year to year variability and improve the overall predictive capability of the model. / Thesis (Master, Civil Engineering) -- Queen's University, 2013-10-22 17:14:23.322

<p>Two ecological models of nitrogen processes in treatment wetlands have been evaluated and compared. These models have been implemented, simulated, and visualized in the Modelica language. The differences and similarities between the Modelica modeling environment used in this thesis and other environments or tools for ecological modeling have been evaluated. The modeling tools evaluated are PowerSim, Simile, Stella, the MathModelica Model Editor, and WEST. </p><p>The evaluation and the analysis have been performed using McCall’s factors for software quality (McCall et al, 1977), a correlation analysis and the Constant Comparative Method (Glaser&Strauss, 1999). The results show that the modeling tools and the models can both be separated into two categories: Simple Components and Complex Components for the modeling tools, and Simple Models and Complex Models for the models. The major difference between the Simple Components and the Complex Components is the higher possibility of the Complex Components to create and reuse separate components and the higher complexity in these components. The similarities between the categories are that they are consistent, easy to overview and use, if no new components are to be created. The major difference between the Simple Models and the Complex models lies in the number of functions and in the possibility of reuse and expansion. The similarities between all the models are that they are all consequent, logical, valid, specialized, and easy to use if the user has programming skill. </p><p>To conclude thisthesis, the nitrogen decrease in a constructed treatment wetland can well be simulated using the Nitrification/Denitrification model expressed in Modelica and the MathModelica Model Editor. However, some changes to the Model Editor are recommended to make the creation of the model easier. The most important of these changes are the addition of a tutorial, the ddition of useful error handling and messages, and the removal of unnecessary Visio features.</p>

Decreasing the nitrogen transport from land to surrounding seas is a major task throughout the world to limit eutrophication of the coastal areas. Several approaches are currently used, including the establishment of wetlands, to decrease the transport of nitrogen. Wetlands represent ecosystems where the nitrogen removal from water can be efficient given that they are appropriately designed. The aim of this thesis was to investigate and quantify the effect of critical factors that regulate the nitrogen removal in wetlands, and to develop better guidelines for wetland design. Studies were performed at different scales, from microcosms to full scale wetlands, and methods included modelling, mass balance calculations and process studies. A first order rate model was used to simulate the nitrogen transformations in two large wetlands treating wastewater containing both ammonium and nitrate nitrogen. It was found that the dynamics of the main itrogen transformation processes could not be satisfactorily described using this approach. Large wetlands containing vegetation are complex ecosystems, and the process rates vary in both time and space. The great diversity of microenvironments favours different nitrogen processes, and large differences in potential nitrification and denitrification rates were found between different surface structures within a wetland. The results from microcosms measurements showed that the highest potential for nitrification was on surfaces in the water column, while the denitrification capacity was highest in the sediment. For the sediment denitrification capacity, the plant community composition was shown to be of major importance primarily by supplying litter serving as a carbon and energy source, and/or attachment surfaces, for denitrifying bacteria. Denitrification rates may be affected more than three fold by different types of litter and detritus in the sediments. Intact sediment cores from stands of the emergent plants Glyceria maxima and Typha latifolia had higher denitrification potential than sediment cores from stands of the submersed plant Potamogeton pectinatus. However, the quality of the organic material for the denitrifying bacteria was highest in G. maxima and P. pectinatus stands. All sediment cores from the wetland were limited by carbon, and the lower denitrification capacity of the submersed plant, P. pectinatus, was likely due to lower amounts of organic matter. However, in another wetland, intact cores from stands of the submersed plant Elodea canadensis had a higher denitrification capacity than the cores from stands of T. latifolia and Phragmites australis. This was possibly due to a larger biomass, and better quality, of the organic matter from that submersed specie, or to epiphytic biofilms on the living plants. Those microcosms studies showed that both the quality of the organic matter as a substrate for the microbial communities, and the amount of organic material produced were important for the denitrification capacity. In pilot scale wetlands, the composition of the plant community was also a more important factor for high nitrate removal than the differences in hydraulic loads (equivalent of 1 or 3 d retention time), despite the cold climate. The greatest removal was found in wetlands with emergent vegetation dominated by P. australis and G. maxima, rather than in wetlands with submersed vegetation. In brief, the results presented in this thesis emphasize the importance of dense emergent vegetation for high annual nitrate removal in treatment wetlands.

Two ecological models of nitrogen processes in treatment wetlands have been evaluated and compared. These models have been implemented, simulated, and visualized in the Modelica language. The differences and similarities between the Modelica modeling environment used in this thesis and other environments or tools for ecological modeling have been evaluated. The modeling tools evaluated are PowerSim, Simile, Stella, the MathModelica Model Editor, and WEST. The evaluation and the analysis have been performed using McCall’s factors for software quality (McCall et al, 1977), a correlation analysis and the Constant Comparative Method (Glaser&amp;Strauss, 1999). The results show that the modeling tools and the models can both be separated into two categories: Simple Components and Complex Components for the modeling tools, and Simple Models and Complex Models for the models. The major difference between the Simple Components and the Complex Components is the higher possibility of the Complex Components to create and reuse separate components and the higher complexity in these components. The similarities between the categories are that they are consistent, easy to overview and use, if no new components are to be created. The major difference between the Simple Models and the Complex models lies in the number of functions and in the possibility of reuse and expansion. The similarities between all the models are that they are all consequent, logical, valid, specialized, and easy to use if the user has programming skill. To conclude thisthesis, the nitrogen decrease in a constructed treatment wetland can well be simulated using the Nitrification/Denitrification model expressed in Modelica and the MathModelica Model Editor. However, some changes to the Model Editor are recommended to make the creation of the model easier. The most important of these changes are the addition of a tutorial, the ddition of useful error handling and messages, and the removal of unnecessary Visio features.

Spillvattenvåtmarker är vattenmiljöer skapade i syfte att avskilja näringsämnen ur spillvatten från avloppsreningsverk med hjälp av naturliga nedbrytningsprocesser. Anläggningarna bidrar till att minska belastningen av näringsämnen och föroreningar till våra sjöar och hav samtidigt som de skapar mervärden som ökad biologisk mångfald. Fåglar vistas gärna i och omkring näringsrika spillvattenvåtmarker till följd av den goda födotillgången samt att det råder en brist på våtmarksmiljöer i Sverige. Syftet med denna studie var att undersöka hur kombinerade fågel- och spillvattenvåtmarker bör utformas och skötas för att uppnå bästa möjliga avskiljning av näringsämnen samtidigt som livsmiljöer för våtmarksfåglar skapas och upprätthålls. Genom att studera litteratur och rapporter om hur respektive våtmarkstyp utformas och sköts på bästa sätt för sitt specifika ändamål kunde en checklista över utformningar som gynnar båda syftena tas fram. Vidare applicerades denna checklista på ett utformningsförslag av en kombinerad fågel-och spillvattenvåtmark i syfte att utvärdera listans potential. Utformningar som stränder med låg släntlutning, öar och öppna vattenpartier står inte i konflikt med de reningsprocesser som krävs för en god avskiljning av näringsämnen.Däremot bidrar denna studie inte med några bevis för att reningseffekten inte påverkas av att spillvattenvåtmarker utformas för att gynna fåglar. Vidare utgör checklistan en övergripande guide för implementering av utformningar och skötsel som främjar fågellivet. Bedömningen av ett utformningsförslag med hjälp av checklistan visade att skötsel spelar en avgörande roll för en lyckad fågel- och spillvattenvåtmark. Slutsatsen av studien är att det finns stora möjligheter att kombinera spillvattenrening med lämpliga miljöer för våtmarksfåglar i en spillvattenvåtmark. / Treatment wetlands are water features created with the purpose of removing nutrients from wastewater treatment effluent by natural processes. These wetlands help to reduce the amount of nutrients and pollution being released into our lakes and seas. At thesame time as they contribute to increased biodiversity. Birds congregate in and around nutrient rich treatment wetlands due to the abundance of food and general lack of wetland habitats in Sweden. The purpose of this study was to evaluate how combined bird and treatment wetlands should be constructed and maintained in order to achieve the best possible retention of nutrients and concurrently provide valuable habitats for wetland birds. By studying literature and reports, regarding how the two specific wetland types are most appropriately shaped and maintained, a checklist of features that support both purposes could be presented. Furthermore, this checklist was applied to an existing proposal of a combined bird and treatment wetland to evaluate the checklists applicability. Constructions such as banks with low slope gradient, islands and areas of open water are not considered to cause a conflict with the processes required for effective nutrient retention. However, this study does not bring data to conclude that the overall nutrient retention is not affected by changes made to improve the wetland for birds. The checklist provides a general guide concerning what structures and maintenance routines support a variety of birds in a treatment wetland. By evaluating the proposed bird and treatment wetland using the checklist the results showed that management of vegetation structures plays an important role in creating a successful bird and treatment wetland. In conclusion, the possibilities of creating treatment wetlands that support nutrient retention and a rich and diverse birdlife simultaneously are plentiful.

No description available.

Floating treatment wetlands (FTWs) are an innovative best management practice that can enhance the performance of traditional retention ponds by increasing removal of the nutrients nitrogen (N) and phosphorous (P). FTWs consist of floating rafts on which wetland plants are planted, allowing the roots to be submerged below the water surface while the shoots remain above. A growing body of research has documented FTW performance with regard to urban runoff treatment, however evaluation of FTW effectiveness for treatment of agricultural runoff has received less attention. Due to high fertilization and irrigation rates, commercial nursery runoff contains much higher concentrations of N and P than runoff from urban areas. We conducted this study over two growing seasons (2015 and 2016) to assess the effectiveness of FTWs for use in commercial nursery retention ponds. In the first study we used two different nutrient concentrations, one to simulate nursery runoff (17.1 mg∙L-1 TN and 2.61 mg∙L-1 TP) and one to simulate concentrations that fall between urban and nursery runoff (5.22 mg∙L-1 TN and 0.52 mg∙L-1 TP). Four treatments were used: 1) Pontederia cordata planted in cups supported by a Beemat, 2) Juncus effusus planted in cups supported by a Beemat, 3) a Beemat with no plants, and 4) no treatment (open-water). Performance was evaluated based on a 7-day hydraulic retention time (HRT). Pontederia cordata removed between 90.3% and 92.4% of total phosphorus (TP) and 84.3% and 88.9% total nitrogen (TN), depending on initial loads. These reductions were significantly more than other treatments at both high and low nutrient loading rates. Juncus effusus performed better than the control treatments for TP removal at low nutrient concentrations, but did not perform any better than the control at higher nutrient loads. In the second study, conducted in 2016, we evaluated different plant species over two 8-week trials using simulated nursery runoff. We used five monoculture FTWs with the following species: Agrostis alba, Canna ×generalis, Carex stricta, Iris ensata, and Panicum virgatum. Additionally, two treatments were created from mixed species plantings and the final treatment consisted of an open water control mesocosm. Nutrient removal performance was evaluated over a 7-day HRT. P removal (phosphate-P) by FTW treatments ranged from 26.1% to 64.7% for trial 1 and 26.8% to 63.2% for trial 2. Trial 1 N removal (sum of ammonium-N, nitrate-N, and nitrite-N) efficiencies ranged from 38.9% to 82.4%, and trial 2 ranged from 12.9% to 59.6%. Panicum virgatum removed significantly more N and P than the control and any other FTW treatment in the second study. Both studies indicated, depending upon plant species, that FTWs can effectively remove nitrogen and phosphorous from urban and commercial nursery retention ponds. / Master of Science

The aim of this report is to present a proposal for a constructed wetland as a complement toHaga treatment plants, Surahammar. First, a literature study in the subject was made andthen a case study was conducted, where Ekeby and Trosa wetland was visited. Parallel anarchival study was performed and several field visits were made to the proposed site toinvestigate the local conditions for constructing a wetland adjacent to Haga treatment plants.Finally, a proposal for the design of the constructed wetland was made. The proposalincludes an oxygenating area for reduction of ammonium to nitrate followed by a system ofdams and channels to convert nitrate to nitrogen diffuses into the air. Phosphorus removaltakes place throughout the residence time in the wetland, as well as reduction of the bacterialload. Expected results for the outgoing water from the wetland is that P-tot can be reduced to0.10-0.11 mg / l, N-tot can be reduced to 11-14 mg / l, a reduction of E. coli, fecal streptococciand intestinal streptococci by 70-99% and a little reduction of residues from drugs take placedue to oxygenation and the UV-irradiation of the water. / Allt vatten här på jorden ingår i den hydrologiska cykeln, så även det renade avloppsvattnet.Avloppsvatten innehåller bland annat kväve och fosfor vilka bidrar till övergödningen avsjöar, vattendrag och hav. Övergödningen är ett utbrett problem och i Västmanland är 53 %av länets sjöar och vattendrag utsatta för det.Syftet med den här rapporten är att ta fram ett förslag till våtmark för Haga reningsverk,Surahammar. Först har information om hur en våtmark kan användas för efterpolering avrenat avloppsvatten tagits fram för att därefter nyttjas som grund i ett förslag till våtmark förHaga reningsverk, Surahammar. Först gjordes en litteraturstudie inom ämnesområdet ochdärefter gjordes en fallstudie där Ekeby och Trosa våtmark besöktes. Parallellt utfördes enarkivstudie och flera områdesbesök på den tilltänkta platsen för att få fram vilkaförutsättningar som finns för att anlägga en våtmark i anslutning till Haga reningsverk ochsist gjordes ett förslag på en våtmark.Anledningen till att anlägga en våtmark kan vara flera, men att avskilja fosfor, kväve samtbryta ner organiskt material är vanliga orsaker. En våtmark fungerar som ett kompletterandesteg till det ordinarie reningsverket och minskar belastningen på recipienten. Hur mycketutsläppen reduceras beror på många faktorer och egenskaper där utformning, vattnetsuppehållstid, syresättning och tillgång till organiskt material är viktiga men även parametrarsom förbehandling av avloppsvattnet och belastningen på våtmarken spelar stor roll. Ävenväxtligheten i våtmarken påverkar det slutliga resultatet, både vad det gäller vad och hurmycket som avskiljs. Avskiljningen av fosfor och kväve sker främst genom sedimentation ochnäringsupptag till växter samt att kväve även avskiljs vid denitrifikation. För den långsiktigaavskiljningen av kväve från vattnets kretslopp är nitrifikation och denitrifikation de som harstörst betydelse. Nitrifikationsprocessen är när ammoniumjoner omvandlas till nitratjoneroch det kräver god tillgång på syre, därefter följer denitrifikationen när nitratjonerna undersyrefria förhållanden omvandlas till kvävgas som diffunderar upp i atmosfären. För attnitrifikationsprocessen ska kunna fungera krävs antingen att det finns ennitrifikationsanläggning i reningsverket eller en syresättningsfas i våtmarken. Det kan skapasgenom att börja våtmarken med en översilningsäng, där det renade avloppsvattnet får strilaner över en bevuxen äng. Vattnet syresätts av luften och nitrifikationsbakterier som trivs bra iväxtligheten utför nitrifikationsprocessen och omvandlar ammoniumjonerna till nitratjoner.Därefter följer ett system av dammar och kanaler där denitrifikationsprocessen tar vid ochomvandlar nitratjonerna till harmlöst kväve. Även i dammar och kanaler har växtlighetenstor betydelse eftersom det bildas biofilm, ett tunt lager av bakterier på växterna, som deltar iden biologiska processen av nedbrytning av organiskt material samt avskiljning av fosfor ochkväve i vattnet.När vattnet passerar genom våtmarken sker också en reducering av antalet bakterier somfinns i det renade avloppsvattnet. Mätningar av E. coli, fekala streptokocker, Koliformabakterier och intestinala enterokocker visar på att halterna kan reduceras kraftigt. Även vissaläkemedel visar tendenser till att brytas ned, men läkemedel är en komplex grupp och detfinns begränsad kunskap om deras omvandling och påverkan i miljön. Det finns dock indikationer om att nedbrytningen av läkemedelsrester är högre i de våtmarker som harsyresättande delar som till exempel översilningsäng.Haga reningsverk är beläget strax utanför Surahammars tätort och har idag en kulvert somleder ut det renade avloppsvattnet från verket till recipienten. Mellan Haga och recipientenligger ett markområde på cirka 750 gånger 750 meter som skulle kunna utnyttjas till envåtmark. Redan idag ligger utsläppsvärdena för Haga reningsverk under de tillåtna halternamen en önskan att ytterligare minska belastningen på miljön finns. Vid analysering avutsläppsvärden för Haga reningsverk framkom att ammoniumkväve utgör en stor andel avutgående totalkväve samt att halterna av totalfosfor, BOD7 och suspenderade ämnen är lågatill måttliga. Ett förslag på våtmark anpassat till de förutsättningar som råder vid Hagareningsverk har tagits fram och presenteras i rapporten. Våtmarken föreslås innehålla tvåsektioner med först en översilningsäng för att reducera den höga andelen ammoniumkväveoch därefter ett damm och kanalsystem för att reducera nitratkvävet. Under hela processensker avskiljning av fosfor samt reducering av bakterier och en viss nedbrytning avläkemedelsrester. Förväntade resultat för det utgående vattnet från våtmarken är att P-totkan reduceras till 0,10–0,11 mg/l, N-tot kan reduceras till 11–14 mg/l, en reducering av E.coli, fekala streptokocker och intestinala streptokocker med 70-99 % samt att en vissminskning sker av läkemedelsrester tack vare syresättning och solens UV-bestrålning avvattnet.