Permeable pavements are a type of sustainable urban drainage system (SUDS)technique that are used around the world to infiltrate and treat urban Stormwater runoff and to minimize runoff volumes. Urban stormwater runoff contains significant concentrations of suspended sediments that can cause clogging and reduce the infiltration capacity and effectiveness of permeable pavements. It is important for stormwater managers to be able to determine when the level of clogging has reached an unacceptable level, so that they can schedule maintenance or replacement activities as required. Newly-installed permeable pavements in the Netherlands must demonstrate a minimum infiltration capacity of 194 mm/h (540 l/s/ha). Other commonly used permeable pavement guidelines in the Netherlands recommend that maintenance is undertaken on permeable pavements when the infiltration falls below 0.50 m/d (20.8 mm/h). This study used a newly-developed, full-scale infiltrationtest procedure to evaluate the infiltration performance of eight permeable pavements in five municipalities that had been in service for over seven years in the Netherlands. The determined infiltration capacities vary between 29 and 342 mm/h. Two of the eight pavements show an infiltration capacity higher than 194 mm/h, and all infiltration capacities are higher than 20.8 mm/h. According to the guidelines, this suggests that none of the pavements tested in this study would require immediate maintenance.
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The rain gardens at Bryggen in Bergen, Western Norway, is designed to collect, retain, and infiltrate surface rainfall runoff water, recharge the groundwater, and replenish soil moisture. The hydraulic infiltration capacity of the Sustainable Drainage System (SuDS), here rain gardens, has been tested with small-scale and full-scale infiltration tests. Results show that infiltration capacity meets the requirement and is more than sufficient for infiltration in a cold climate. The results from small-scale test, 245–404 mm/h, shows lower infiltration rates than the full-scale infiltration test, with 510–1600 mm/h. As predicted, an immediate response of the full-scale infiltration test is shown on the groundwater monitoring in the wells located closest to the infiltration point (<30 m), with a ca. 2 days delayed response in the wells further away (75–100 m). Results show that there is sufficient capacity for a larger drainage area to be connected to the infiltration systems. This study contributes to the understanding of the dynamics of infiltration systems such as how a rain garden interacts with local, urban water cycle, both in the hydrological and hydrogeological aspects. The results from this study show that infiltration systems help to protect and preserve the organic rich cultural layers below, as well as help with testing and evaluating of the efficiency, i.e., SuDS may have multiple functions, not only storm water retention. The functionality is tested with water volumes of 40 m3 (600 L/min for 2 h and 10 min), comparable to a flash flood, which give an evaluation of the infiltration capacity of the system.
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Over the past decades, various types of permeable pavements have been implemented in different municipalities in the Netherlands in order to improve infiltration capacity in urban areas and therewith being able to better treat stormwater runoff. With initial promising results, this adaptation measure seemed to be the solution for urban flooding due to extreme precipitation.However, in practice, foreseen infiltration capacities were usually not met, often due to unknown reasons. To better understand the functioning of permeable pavements in practice, we have studied - as part of the project Infiltrating Cities - over 100 existing permeable pavement installations in the Netherlands. At each location, infiltration capacity was tested through a full-scale infiltration testing procedure (flooded area about 40 m2) while conditional on-site factors were collected (location, age, type of permeable pavement, street-type, traffic density, vicinity of urban green, regular maintenance regime, etc.). By coupling this information we analyzed how these factors influence the infiltration capacity of permeable pavements in practice, e.g. through accelerated deterioration of infiltration capacity through time. In addition, we evaluated for a selected number of installations, how various types of maintenance may counteract this deterioration, hence improving the infiltration capacity of permeable pavements.
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Although permeable pavements have been used all over the world in recent years to infiltrate and treat stormwater, only limited research has been undertaken to investigate and compare the long-term performance of these sustainable urban drainage system devices. This paper presents the results of an extensive international review of research on the reduction of infiltration capacity of permeable pavements over time. The results of these studies, coupled with specific knowledge of the key environmental factors on the individual research locations and infiltration testing methods used, enables the maintenance of these SUDS to be strategically planned in order to meet specific European and international infiltration capacity guidelines.
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This research used a newly developed, full-scale infiltration testing (FSIT) procedure to determine the saturated surface infiltration rate of 16 existing permeable pavement installations in the Netherlands that have been in service for a number of years. Newly installed permeable pavements in the Netherlands must demonstrate a minimum infiltration capacity of 194 mm/h (540 L/s/ha). Only four of the 16 pavements tested in this study had an infiltration capacity higher than 194 mm/h. Most previous research has focused on unsaturated infiltration rates. However, the results of this study show that the difference in infiltration capacity between saturated and unsaturated can differ by up to 300%. If the unsaturated infiltration capacity is used as design input for computer models, the infiltration capacity may be significantly overestimated. The study demonstrated that the FSIT method is a reliable and accurate way to measure surface infiltration rates of permeable pavements. However, it is recommended that a minimum of three different FSIT tests should be undertaken at the same pavement location, and that the results should be averaged, to ensure appropriate infiltration rates are observed, recorded, and used in design. The results of this study should help stormwater managers with the planning, testing, and scheduling of maintenance requirements for permeable pavements with more confidence so that they will continue to perform satisfactorily over their intended design life
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This study describes field investigations designed to compare the infiltration capacities of 55 permeable pavement systems installed in the Netherlands and in Australia. The ages of the pavements varied from 1 to 12 years. Using infiltrometer testing, the performance of the pavements has been compared in terms of their ability to infiltrate a three month average recurrence interval storm event in the case of the Australian pavements or the minimum specification for European infiltration capacities of 97.2 mm/h for the Dutch pavements. Many of the tested pavements broadly follow a hypothetical decay curve of infiltration rate with age of pavement. However, these are clustered into two distinct groups (Dutch and Australian) with the older Australian pavements appearing to maintain higher infiltration rates relative to their age. The study has shown that the performance of the clogged permeable pavement systems was still generally acceptable, even after many years in service.
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Permeable pavements are a type of SUDS that are becoming more common to allow infiltration, to minimize runoff volumes and to treat urban water stormwater by soil filtration. However, urban stormwater runoff contains significant concentrations of suspended sediments that can cause clogging and reduce the infiltration capacity and effectiveness of permeable pavements. This study used a full-scale infiltration test procedure to evaluate the infiltration performance of 20 permeable pavements that have been in service for over 2 to 9 years in the Netherlands. The observed infiltration capacities range between 20 and 342 mm/h.
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Permeable pavements are specifically designed to promote the infiltration of stormwater through the paving surface in order to reduce run-off volumes and to improve water quality by removing sediment and other pollutants. However, research has shown that permeable pavements can become clogged over time and this reduces their infiltration capacity. In order to assess the infiltration of permeable pavements, a variety of infiltration test procedures have been utilised in the past. However, the results have generally been inconsistent, and have shown a large variation in the range of infiltration rates measured. This paper evaluates the performance of two new experimental test methods developed in the Netherlands to more accurately determine the surface infiltration rate of existing permeable pavement installations. The two methods were the falling head full-scale method and the constant head full-scale method. Both of the new methods involved inundating a large area of the pavement in order to determine the infiltration rate through the pavement surface. Double ring infiltrometer tests were also performed to enable a comparison of the results. The study found that the new falling head full-scale testing method produced the most accurate results.
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Urbanisation and climate change have an effect on the water balance in our cities resulting in challenges as flooding, droughts and heatstress. Implementation of Sustainable Urban Drainage Systems (SuDS) can help to restore the water balance in cities by storing and infiltrating stormwater into the subsurface to minimise flooding, restoration of groundwater tables to prevent droughts, lowering temperatures by evapotranspiration to fight heatstress. Urban planners and otherstakeholders in municipalities and water authorities struggle with implementing SuDS at locations where infiltration of water seems challenging. Questions arise as: can you infiltrate in countries as The Netherlands with parts under sea level, high groundwater table and low permeable soil? Can you infiltrate in Norway with low permeable or impermeable bedrock and frozen ground most of theyear? How do you find space to implement SuDS in the dense urban areas of Bucharest? These questions are answered by researchers of the JPI Water funded project INovations for eXtreme Climatic Events (INXCES).To answer the question on ‘can we infiltrate stormwater under worse case conditions?’, testing of the hydraulic capacity take place at rainwater gardens in Norway (Bergen and Trondheim) and (bio)swales in the low lying parts of The Netherlands. The first results show that even under these ‘extreme’ hydraulic circumstances the hydraulic capacity (or empty time) is sufficient to infiltratemost of the stormwater throughout the year.INXCES exchanged researchers on an international level, shared research results with stakeholders and sets up guidelines for design, implementation and maintenance of SuDS to promote the implementation of sustainable water management systems throughout the world.One of the tools used to promote SuDS is www.climatescan.nl, an open source online map application that provides an easy-to-access database of international project information in the field of urban resilience and climate adaptation. The tool is able to map several sustainable urban drainage systems as has been done for Norway, The Netherlands, Romania and other countries in the world.The tool is used for engagement with stakeholders within EU projects as INXCES and WaterCoG and resulted in international knowledge exchange on infiltration of stormwater under extreme climate and geohydrolic circumstances.
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Background: Intravenous (IV) therapy using short peripheral IV catheters (PIVC) is commonplace with neonatal patients. However, this therapy is associated with high complication rates including the leakage of infused fluids from the vasculature into the surrounding tissues; a condition referred to as, peripheral IV infiltration/extravasation (PIVIE). Objective: The quality improvement project aimed to identify the prevalence of known risk factors for PIVIE in the neonatal intensive care unit (NICU) and explore the feasibility of using novel optical sensor technology to aid in earlier detection of PIVIE events. Methods: The plan, do, study, act (PDSA) model of quality improvement (QI) was used to provide a systematic framework to identify PIVIE risks and evaluate the potential utility of continuous PIVC monitoring using the ivWatch model 400® system. The site was provided with eight monitoring systems and consumables. Hospital staff were supported with theoretical education and bedside training about the system operations and best use practices. Results: In total 113 PIVIE's (graded II-IV) were recorded from 3476 PIVCs, representing an incidence of 3.25%. Lower birth weight and gestational age were statistically significant factors for increased risk of PIVIE (p = 0.004); all other known risk factors did not reach statistical significance. Piloting the ivWatch with 21 PIVCs using high-risk vesicant solutions over a total of 523.9 h (21.83 days) detected 11 PIVIEs (graded I-II). System sensitivity reached 100%; 11 out of 11 PIVIEs were detected by the ivWatch before clinician confirmation. Conclusions: Prevailing risk factors for PIVIE in the unit were comparable to those published. Continuous infusion site monitoring using the ivWatch suggests this technology offers the potential to detect PIVIE events earlier than relying on intermittent observation alone (i.e. the current standard of care). However, large-scale study with neonatal populations is required to ensure the technology is optimally configured to meet their needs.
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