Change search
Link to record
Permanent link

Direct link
BETA
Ashley, Richard
Publications (10 of 16) Show all publications
Panasiuk, O., Hedström, A., Ashley, R., Marsalek, J. & Viklander, M. (2019). The feasibility of using flap gates as constriction flow meters for estimating sanitary sewer overflows (SSO). Desalination and Water Treatment, 155, 113-119
Open this publication in new window or tab >>The feasibility of using flap gates as constriction flow meters for estimating sanitary sewer overflows (SSO)
Show others...
2019 (English)In: Desalination and Water Treatment, ISSN 1944-3994, E-ISSN 1944-3986, Vol. 155, p. 113-119Article in journal (Refereed) Published
Abstract [en]

Increased awareness of the negative effects of sanitary sewer overflow (SSO) events on human health and aquatic life led to the development of various control measures, of which implementation is impeded by the lack of information on SSO occurrences, flows and volumes. The collection of such information requires data acquisition systems, which can be costly and are fully utilized just during limited time periods of the year. In search for inexpensive approaches to SSO monitoring, the feasibility of using existing flap gate installations, serving for prevention of back-up flows into sewers, as constriction flow meters was investigated, with promising results. An experimental pilotscale setup was designed to allow steady water flow through a flap gate built into a partition wall between two chambers. The stabilized water heads in the chambers and the flow rate through the flap gate were measured, for both dry and submerged flap gate conditions, and five flap gate sizes (200, 300, 400, 500 and 600 mm), with relatively heavy covers (6–102 kg). The measured data were used to develop flow rating curves, by non-linear regression, in the form Q = f (ΔH), where Q is the discharge through the flap gate and ΔH is the pressure differential upstream and downstream of the gate. The regression curves fitted the experimental data with high precision (R2 >0.99). The use of flow rating curves for estimation of the SSO volume was discussed. This study demonstrated that the water head measurements upstream and downstream of the flap gate can provide a reliable, accurate and inexpensive method for quantification of the SSO discharges and volumes.

Place, publisher, year, edition, pages
Desalination Publications, 2019
Keywords
Flap gates, Sanitary sewer overflows (SSO), SSO volumes
National Category
Water Engineering
Research subject
Urban Water Engineering
Identifiers
urn:nbn:se:ltu:diva-74804 (URN)10.5004/dwt.2019.24011 (DOI)000470121900011 ()2-s2.0-85067931662 (Scopus ID)
Note

Validerad;2019;Nivå 2;2019-06-20 (johcin)

Available from: 2019-06-20 Created: 2019-06-20 Last updated: 2019-08-19Bibliographically approved
Mattsson, J., Hedström, A., Westerlund, L., Dahl, J., Ashley, R. & Viklander, M. (2018). Impacts on rural wastewater systems in subarctic regions due to changes in inputs from households (ed.). Journal of cold regions engineering, 32(1), Article ID 04017019.
Open this publication in new window or tab >>Impacts on rural wastewater systems in subarctic regions due to changes in inputs from households
Show others...
2018 (English)In: Journal of cold regions engineering, ISSN 0887-381X, E-ISSN 1943-5495, Vol. 32, no 1, article id 04017019Article in journal (Refereed) Published
Abstract [en]

The use of water-saving appliances and heat exchangers is becoming increasingly popular to decrease water consumption and recover energy from preheated water. However, such in-household changes can bring particular implications for subarctic rural areas, in terms of solids deposition in sewers and drops in performance of wastewater treatment plants (WWTPs), because these are already experiencing diminishing wastewater flows due to depopulation and seasonal dips in wastewater temperature resulting from infiltration into sewers. Hence, this study has considered two communities in Sweden, postulating three different cases with various scales of retrofitting and usage. The results indicate that the decrease in in-pipe velocities when all households are retrofitted with water-saving appliances could be counteracted by sewer relining, but not by the inclusion of a conventional estimate of infiltration. However, for the case in which retrofitting was combined with decreased usage of the appliances, the decrease in self-cleansing capacity could not be counteracted. The retrofitting of heat exchangers under shower trays in all households did not have a significant effect on treatment processes at the WWTP.

Place, publisher, year, edition, pages
American Society of Civil Engineers (ASCE), 2018
National Category
Water Engineering Energy Engineering
Research subject
Urban Water Engineering; Energy Engineering
Identifiers
urn:nbn:se:ltu:diva-14539 (URN)10.1061/(ASCE)CR.1943-5495.0000145 (DOI)000428257200005 ()2-s2.0-85030121882 (Scopus ID)de948167-31d8-4bac-a3d7-ca6af781096b (Local ID)de948167-31d8-4bac-a3d7-ca6af781096b (Archive number)de948167-31d8-4bac-a3d7-ca6af781096b (OAI)
Note

Validerad;2017;Nivå 2;2017-09-25 (andbra)

Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2018-04-20Bibliographically approved
Panasiuk, O., Hedström, A., Ashley, R. & Viklander, M. (2016). Detection of Wastewater Discharges into Stormwater Sewers: Effects of Travel Distance on Parameters (ed.). Journal of environmental engineering, 142(5), Article ID 4016016.
Open this publication in new window or tab >>Detection of Wastewater Discharges into Stormwater Sewers: Effects of Travel Distance on Parameters
2016 (English)In: Journal of environmental engineering, ISSN 0733-9372, E-ISSN 1943-7870, Vol. 142, no 5, article id 4016016Article in journal (Refereed) Published
Abstract [en]

In separate sewer systems, there is a risk that wastewater from illicit connections may enter a stormwater sewer and ultimately outfall into receiving waters, adversely affecting receiving water quality and increasing risks to public health. A common approach in using methods for the detection of wastewater pollution in stormwater systems for some municipalities is to take grab samples at the outlet of a stormwater sewer, some distance away from the point(s) of ingress of the pollution. However, once pollution enters a stormwater network, the concentration or detectability of indicator parameters may change. The aim of this study was to evaluate the variation in detectability of various wastewater quality parameters depending upon the distance from the point of ingress of the wastewater into a stormwater sewer. This includes E. coli, total coliform, Enterococci, conductivity, turbidity, total suspended solids, and ammonium. This study introduces a maximum detection distance—the maximum distance at which the detection of individual quality parameters would no longer be reliable. Recommendations on planning a wastewater detection program and selecting appropriate indicator parameters are given.

National Category
Water Engineering
Research subject
Urban Water Engineering
Identifiers
urn:nbn:se:ltu:diva-15612 (URN)10.1061/(ASCE)EE.1943-7870.0001086 (DOI)000374868700007 ()2-s2.0-84964715431 (Scopus ID)f2785152-3502-428e-9b68-a426a7775772 (Local ID)f2785152-3502-428e-9b68-a426a7775772 (Archive number)f2785152-3502-428e-9b68-a426a7775772 (OAI)
Note

Validerad; 2016; Nivå 2; 20160126 (olepan)

Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2019-08-14Bibliographically approved
Panasiuk, O., Hedström, A., Ashley, R. & Viklander, M. (2016). Monte Carlo simulation for localisation and volume estimation of wastewater contamination in stormwater sewers. In: NOVATECH 2016: . Paper presented at 9th International Conference NOVATECH Lyon, Planning and technologies for sustainable urban water management, June 28 - July 1, 2016.
Open this publication in new window or tab >>Monte Carlo simulation for localisation and volume estimation of wastewater contamination in stormwater sewers
2016 (English)In: NOVATECH 2016, 2016Conference paper, Published paper (Refereed)
Abstract [en]

In separate sewerage systems the sewage may find its way into the stormwater sewer network, impairing the quality and increasing the risks to public health and aquatic organisms. Detecting the presence and localising the point of ingress of wastewater in stormwater systems can be a challenging task because of the variable sources, regularity, consistency and flow rates of incoming wastewater. This paper suggests a method for the estimation of the volumes of wastewater inflow to a stormwater system and localising its point of ingress by using Monte Carlo simulation. The developed method showed varying efficiency depending on the selected combination of pollutant parameters. More experiments on the rates of concentration changes of parameters over the travel distance are suggested to increase the accuracy of the method.

Abstract [fr]

Dans un système d’égout séparatif, il arrive qu’une partie des eaux usées trouve son chemin jusqu’au réseau de drainage des eaux de pluies. Il en résulte une dégradation de la qualité des eaux de pluie déchargées, ce qui augmente le risque sanitaire pour la population et la flore aquatique environnante. Détecter et localiser les points d’entrée des eaux usées dans le système de gestion des eaux pluviales peut être particulièrement difficile. En effet, l’entrée des eaux usées peut se faire à différents débits, de manière plus ou moins régulière, et depuis différentes sources. Cet article propose une méthode pour la localisation de ces points d’entrée ainsi que l’estimation des volumes associés, ceci en utilisant la simulation Monte Carlo. La méthode développée montre différents niveaux d’efficacité suivant la combinaison de paramètres de pollution choisie. Pour améliorer la précision de cette approche, de futurs travaux sont suggérés concernant la diminution des concentrations de chaque paramètre le long de l’écoulement.

National Category
Water Engineering
Research subject
Urban Water Engineering
Identifiers
urn:nbn:se:ltu:diva-61546 (URN)
Conference
9th International Conference NOVATECH Lyon, Planning and technologies for sustainable urban water management, June 28 - July 1, 2016
Available from: 2017-01-19 Created: 2017-01-19 Last updated: 2018-05-22Bibliographically approved
Panasiuk, O., Hedström, A., Marsalek, J., Ashley, R. & Viklander, M. (2015). Contamination of stormwater by wastewater: A review of detection methods (ed.). Journal of Environmental Management, 152, 241-250
Open this publication in new window or tab >>Contamination of stormwater by wastewater: A review of detection methods
Show others...
2015 (English)In: Journal of Environmental Management, ISSN 0301-4797, E-ISSN 1095-8630, Vol. 152, p. 241-250Article in journal (Refereed) Published
Abstract [en]

Even in separate sewer systems, wastewater may find its way into the receiving waters through stormwater sewers. The main reasons for this are cross-connections, illicit connections, overflows and leakages through broken sewers. Such discharges may affect receiving water quality and increase risks to public health and aquatic organisms. Detecting wastewater contamination and locating its points of ingress into storm sewer systems can be a challenging task, which should be addressed using proper methods and indicator parameters. A number of detection methods have already been proposed in this area, yet there is a lack of a general overview of such methods. This literature review summarizes and evaluates the methods used for detecting wastewater in stormwater, including those recently developed. The advantages, weaknesses and limitations of individual methods are discussed. It is concluded that while no single method can as yet produce results in a precise, fast and inexpensive way, the use of human waste specific chemical and microbiological markers, and their innovative sampling, offer the way forward. Guidance for selecting the most effective combinations of detection methods, under specific conditions, is also provided.

National Category
Water Engineering
Research subject
Urban Water Engineering
Identifiers
urn:nbn:se:ltu:diva-10485 (URN)10.1016/j.jenvman.2015.01.050 (DOI)000350519400028 ()25662485 (PubMedID)2-s2.0-84922983550 (Scopus ID)94d6956e-3585-4759-b466-c7288b2641c6 (Local ID)94d6956e-3585-4759-b466-c7288b2641c6 (Archive number)94d6956e-3585-4759-b466-c7288b2641c6 (OAI)
Note

Validerad; 2015; Nivå 2; 20150205 (andbra)

Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2019-08-15Bibliographically approved
Mattsson, J., Hedström, A., Ashley, R. & Viklander, M. (2015). Impacts and managerial implications for sewer systems due to recent changes to inputs in domestic wastewater: a review (ed.). Paper presented at . Journal of Environmental Management, 161, 188-197
Open this publication in new window or tab >>Impacts and managerial implications for sewer systems due to recent changes to inputs in domestic wastewater: a review
2015 (English)In: Journal of Environmental Management, ISSN 0301-4797, E-ISSN 1095-8630, Vol. 161, p. 188-197Article in journal (Refereed) Published
Abstract [en]

Ever since the advent of major sewer construction in the 1850s, the issue of increased solids deposition in sewers due to changes in domestic wastewater inputs has been frequently debated. Three recent changes considered here are the introduction of kitchen sink food waste disposers (FWDs); rising levels of inputs of fat, oil and grease (FOG); and the installation of low-flush toilets (LFTs). In this review these changes have been examined with regard to potential solids depositional impacts on sewer systems and the managerial implications. The review indicates that each of the changes has the potential to cause an increase in solids deposition in sewers and this is likely to be more pronounced for the upstream reaches of networks that serve fewer households than the downstream parts and for specific sewer features such as sags. The review has highlighted the importance of educational campaigns directed to the public to mitigate deposition as many of the observed problems have been linked to domestic behaviour in regard to FOGs, FWDs and toilet flushing. A standardized monitoring procedure of repeat sewer blockage locations can also be a means to identify depositional hot-spots. Interactions between the various changes in inputs in the studies reviewed here indicated an increased potential for blockage formation, but this would need to be further substantiated. As the precise nature of these changes in inputs have been found to be variable, depending on lifestyles and type of installation, the additional problems that may arise pose particular challenges to sewer operators and managers because of the difficulty in generalizing the nature of the changes, particularly where retrofitting projects in households are being considered. The three types of changes to inputs reviewed here highlight the need to consider whether or not more or less solid waste from households should be diverted into sewers.

National Category
Water Engineering
Research subject
Urban Water Engineering
Identifiers
urn:nbn:se:ltu:diva-16075 (URN)10.1016/j.jenvman.2015.06.043 (DOI)000361264100022 ()26182992 (PubMedID)2-s2.0-84938593759 (Scopus ID)fa88963c-f0d7-410c-8207-1dbb3f8f1fb5 (Local ID)fa88963c-f0d7-410c-8207-1dbb3f8f1fb5 (Archive number)fa88963c-f0d7-410c-8207-1dbb3f8f1fb5 (OAI)
Note
Validerad; 2015; Nivå 2; 20150416 (jonmat)Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2018-07-10Bibliographically approved
Panasiuk, O., Hedström, A., Ashley, R. & Viklander, M. (2015). Not only preventing backflows: Flap gates for the estimation of separate sewer overflow volumes (ed.). Paper presented at NORDIWA 2015 : Nordic Wastewater Conference 04/11/2015 - 06/11/2015. Paper presented at NORDIWA 2015 : Nordic Wastewater Conference 04/11/2015 - 06/11/2015.
Open this publication in new window or tab >>Not only preventing backflows: Flap gates for the estimation of separate sewer overflow volumes
2015 (English)Conference paper, Oral presentation only (Refereed)
Abstract [en]

In practice discharges of untreated wastewater occur from many wastewater sewer systems, often via Sanitary Sewer Overflows (SSO). The untreated wastewater from SSO can be transferred through the overflow systems into receiving waters, reducing their quality and bringing risks to human health and aquatic organisms. Increased awareness of the negative effects of SSOs has led to the development of various control measures as part of watershed protection programs around the world. However, the information the number of SSO events is often unknown due to poor or limited monitoring. A further problem is that backflows can occur through an overflow system, with receiving waters entering the wastewater network due to elevated levels of the receiving waters. This additional relatively clean water often increases the volumes of water that need to be transported to the treatment facility and dilutes wastewater pollutants, resulting in lower treatment efficiency and higher costs for chemicals, increasing electricity consumption for any intermediate booster pumps and within the treatment plant. This paper illustrates how the flap gates, commonly used for preventing these backflows, also can be used for the estimation of SSO discharge volumes. An experimental full-scale setup was designed where sewage flowed through a flap gate between two chambers with a constant flow rate. The stabilised water heads in the two chambers and the flow rate were measured. Experiments were performed for both dry and submerged flap gate conditions (the latter is relevant for the SSO event occurring during high water level in the receiving waters). In total, five flap gates with opening dimensions of 200, 300, 400, 500 and 600 mm were tested and flow rating curves were established with high precision (R2>0.99). Results of the opening pressure tests showed some deviations between the values specified by the manufacturer of the flap gates and the experimentally obtained opening pressure values. An approach to generalising the flow rating curves for other than tested diameters of the flap gates is suggested. The usage of flow rating curves for estimation of the volume is discussed. This study showed that the water head measurements before and after the flap gate can provide a reliable and inexpensive method for quantification of the SSO discharge volumes.

National Category
Water Engineering
Research subject
Urban Water Engineering
Identifiers
urn:nbn:se:ltu:diva-32825 (URN)76f0664b-7cd9-4808-8233-f7c35c3f81b8 (Local ID)76f0664b-7cd9-4808-8233-f7c35c3f81b8 (Archive number)76f0664b-7cd9-4808-8233-f7c35c3f81b8 (OAI)
Conference
NORDIWA 2015 : Nordic Wastewater Conference 04/11/2015 - 06/11/2015
Note
Godkänd; 2015; 20160126 (olepan)Available from: 2016-09-30 Created: 2016-09-30 Last updated: 2018-05-22Bibliographically approved
Leonhardt, G., Bacchin, T. K., Mair, M., Zischg, J., Ljung, S., Rogers, B., . . . Viklander, M. (2015). Relocating a city, challenges and opportunities for the transition of water infrastructure in Kiruna (ed.). In: (Ed.), Thomas Maere; Sovanna Tik; Sophie Duchense; Peter A. Vanrolleghem (Ed.), Urban Drainage Modelling 2015: Proceedings of the 10th International Conference of Urban Drainage Modelling, Mont-Sainte-Anne, Québec, Canada 20-23 Swptember 2015. Paper presented at International Urban Drainage Modelling Conference : 20/09/2015 - 23/09/2015 (pp. 77-84).
Open this publication in new window or tab >>Relocating a city, challenges and opportunities for the transition of water infrastructure in Kiruna
Show others...
2015 (English)In: Urban Drainage Modelling 2015: Proceedings of the 10th International Conference of Urban Drainage Modelling, Mont-Sainte-Anne, Québec, Canada 20-23 Swptember 2015 / [ed] Thomas Maere; Sovanna Tik; Sophie Duchense; Peter A. Vanrolleghem, 2015, p. 77-84Conference paper, Published paper (Refereed)
National Category
Water Engineering
Research subject
Urban Water Engineering
Identifiers
urn:nbn:se:ltu:diva-29886 (URN)380bd5bf-bf6d-49eb-aa80-c63a34f4b3eb (Local ID)380bd5bf-bf6d-49eb-aa80-c63a34f4b3eb (Archive number)380bd5bf-bf6d-49eb-aa80-c63a34f4b3eb (OAI)
Conference
International Urban Drainage Modelling Conference : 20/09/2015 - 23/09/2015
Note
Godkänd; 2015; 20151008 (andbra)Available from: 2016-09-30 Created: 2016-09-30 Last updated: 2017-11-25Bibliographically approved
Ashley, R., Walker, L., D.Arcy, B., Wilson, S., Illmann, S., Shaffer, P. W., . . . Chatfield, P. R. (2015). UK sustainable drainage systems: Past, present and future (ed.). Paper presented at . Proceedings of the Institution of Civil Engeneers: Civil Engineering, 168(3), 125-130
Open this publication in new window or tab >>UK sustainable drainage systems: Past, present and future
Show others...
2015 (English)In: Proceedings of the Institution of Civil Engeneers: Civil Engineering, ISSN 0965-089X, E-ISSN 1751-7672, Vol. 168, no 3, p. 125-130Article in journal (Refereed) Published
Abstract [en]

Urban drainage has developed from an engineering discipline, concerned principally with public health and safety outcomes, into a multifaceted vision linking drainage with environmental and wider social and economic imperatives to deliver multifunctional outcomes. UK attention is too often focused on surface water as ‘a problem’, despite international progress and initiatives showing that an ‘opportunity-centred’ approach needs to be taken. Sustainable drainage systems, or ‘Suds’, can, when they are part of an integrated approach to water management, cost-effectively provide many benefits beyond management of water quality and quantity. New tools are available that can design Suds for maximum value to society but this requires greater collaboration across disciplines to seize all of the opportunities available. This paper introduces those tools and a roadmap for their use, including guidance, design objectives and criteria for maximising benefits. These new supporting tools and guidance can help to provide a business case for greater use of Suds in future

National Category
Water Engineering
Research subject
Urban Water Engineering
Identifiers
urn:nbn:se:ltu:diva-6817 (URN)10.1680/cien.15.00011 (DOI)2-s2.0-84950277315 (Scopus ID)51d0e324-dc68-4b84-b6ef-c45fbd887f0a (Local ID)51d0e324-dc68-4b84-b6ef-c45fbd887f0a (Archive number)51d0e324-dc68-4b84-b6ef-c45fbd887f0a (OAI)
Note
Validerad; 2016; Nivå 2; 20160107 (andbra)Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2018-07-10Bibliographically approved
Cettner, A., Ashley, R., Hedström, A. & Viklander, M. (2014). Assessing receptivity for change in urban stormwater management and contexts for action (ed.). Journal of Environmental Management, 146, 29-41, Article ID 13.
Open this publication in new window or tab >>Assessing receptivity for change in urban stormwater management and contexts for action
2014 (English)In: Journal of Environmental Management, ISSN 0301-4797, E-ISSN 1095-8630, Vol. 146, p. 29-41, article id 13Article in journal (Refereed) Published
Abstract [en]

Individual and organisational receptivity for change towards the use of sustainable stormwater management systems has been previously examined, but the significance of the different contexts for achieving this has been largely unexplored. This paper examines the significance of contexts associated to the actions to bring this about by proposing and evaluating an emerging framework based on two related receptivity theories: the individual or organisational approach and the contextual approach. Results from a Swedish national questionnaire with professionals in stormwater management have been used, together with a limited number of interviews to develop and understand the validity of the framework. The analysis has indicated that the respondents were professionally prepared for change (action) but not practically prepared due to inadequate supportive contexts. In response, a number of potential contexts associated to the necessary actions were identified. The framework was found to provide new insights into the influence of receptive contexts for a change in water management practice. These insights can be used by policy makers and others to better support the realization of professional openness for change and thus accelerate the process of change to sustainable stormwater practice.

National Category
Water Engineering
Research subject
Urban Water Engineering
Identifiers
urn:nbn:se:ltu:diva-11739 (URN)10.1016/j.jenvman.2014.07.024 (DOI)000343614400005 ()25156263 (PubMedID)2-s2.0-84906503480 (Scopus ID)abd62cd3-4187-4667-9d1b-84c7d9064d4d (Local ID)abd62cd3-4187-4667-9d1b-84c7d9064d4d (Archive number)abd62cd3-4187-4667-9d1b-84c7d9064d4d (OAI)
Note

Validerad; 2014; 20121217 (ysko)

Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2018-07-10Bibliographically approved
Organisations

Search in DiVA

Show all publications