The effects of de-icing in Helsinki urban streams, Southern Finland

2003 ◽  
Vol 48 (9) ◽  
pp. 33-43 ◽  
Author(s):  
O. Ruth
Keyword(s):  
Water Quality ◽  
Urban Areas ◽  
Stream Water ◽  
Road Salt ◽  
Urban Streams ◽  
Urban Stream ◽  
Road Maintenance ◽  
Spring Flood ◽  
Natural Streams ◽  
Flood Period

The environmental effects of road salt have been studied in Finland mainly in order to monitor and reduce groundwater contamination. In urban areas the road salt used for road maintenance in winter ends up in the storm water drains and receiving water bodies. We report here on water samples taken in 1998-1999 from three urban streams with catchments varying in area 1.7 to 24.4 km2 in different parts of the City of Helsinki. Despite efforts to reduce the amount of road salt, high concentrations were found in the urban stream water. Sudden variations in water quality were very marked during the spring flood period, with sodium and chloride concentrations varying over nine-fold within one day. Some 35-50% of the salt used on the roads in Helsinki passes into natural streams and from there into the sea. The significant positive correlation between NaCl and dissolved zinc in stream water was observed. The results show that it is important to monitor water quality, especially at the beginning of the spring flood period, when road salt and other contaminant levels are markedly high in urban streams.

scholarly journals Dispersed urban-stormwater control improved stream water quality in a catchment-scale experiment

2021 ◽  
Author(s):  
Christopher John Walsh ◽  
Sam Imberger ◽  
Matthew J Burns ◽  
Darren G Bos ◽  
Tim D Fletcher
Keyword(s):  
Water Quality ◽  
Stream Water ◽  
Control Measure ◽  
Urban Streams ◽  
Septic Tank ◽  
Stream Water Quality ◽  
Urban Stormwater ◽  
Catchment Scale ◽  
Nitrogen Concentrations ◽  
Stormwater Control

Traditional approaches to urban drainage degrade receiving waters. Alternative approaches have potential to protect downstream waters and provide other benefits to cities, including greater water security. Their widespread adoption requires robust demonstration of their feasibility and effectiveness. We conducted a catchment-scale, before-after-control-reference-impact experiment to assess the effect of dispersed stormwater control on stream ecosystems. We used a variant of effective imperviousness (EI), integrating catchment-scale stormwater runoff impact and stormwater-control-measure (SCM) performance, as the measure of experimental effect. We assessed the response of water quality variables in 6 sites on 2 streams, following SCM implementation in their catchments. We compared changes in those streams over 7 years, as SCM implementation increased, to the 12 preceding years, and over the 19 years in 3 reference and 2 control streams. SCMs reduced phosphorus and nitrogen concentrations and temperature, and increased electrical conductivity; with effect size negatively correlated with antecedent rain. SCM-induced reductions in phosphorus and temperature were of a similar magnitude to increases from urban development, when assessed as a function of change in EI. Nitrogen reductions were observed, even though concentrations among sites were not correlated with EI, being more influenced by septic tank seepage. SCMs had no effect on suspended solids concentrations, which were lower in urban streams than in reference streams. This experiment strengthens the inference that urban stormwater drainage increases contaminant concentrations in urban streams, and demonstrates that such impacts are reversible and likely preventable. SCMs reduce contaminant concentrations by reducing the frequency and magnitude of uncontrolled drainage flows and augmenting reduced baseflows. Increased EC and reduced temperature are likely a result of increased contribution of groundwater to baseflows. The stormwater control achieved by the experiment did not fully return phosphorus or nitrogen concentrations to reference levels, but their responses indicate such an outcome is possible in dominant conditions (up to ~20 mm of 24-h antecedent rain). This would require nearly all impervious surfaces draining to SCMs with large retention capacity, thus requiring more downslope space and water demand. EI predicts stream water quality responses to SCMs, allowing better catchment prioritization and SCM design standards for stream protection.

scholarly journals Taxon-Driven Functional Shifts Associated with Storm Flow in an Urban Stream Microbial Community

mSphere ◽  
2018 ◽  
Vol 3 (4) ◽  
Author(s):  
Adit Chaudhary ◽  
Imrose Kauser ◽  
Anirban Ray ◽  
Rachel Poretsky
Keyword(s):  
Public Health ◽  
Water Quality ◽  
Microbial Community ◽  
Microbial Community Composition ◽  
Urban Streams ◽  
Urban Stream ◽  
Flow Conditions ◽  
Shotgun Metagenomics ◽  
Storm Flow ◽  
The Impact

ABSTRACT Urban streams are susceptible to stormwater and sewage inputs that can impact their ecological health and water quality. Microbial communities in streams play important functional roles, and their composition and metabolic potential can help assess ecological state and water quality. Although these environments are highly heterogenous, little is known about the influence of isolated perturbations, such as those resulting from rain events on urban stream microbiota. Here, we examined the microbial community composition and diversity in an urban stream during dry and wet weather conditions with both 16S rRNA gene sequencing across multiple years and shotgun metagenomics to more deeply analyze a single storm flow event. Metagenomics was used to assess population-level dynamics as well as shifts in the microbial community taxonomic profile and functional potential before and after a substantial rainfall. The results demonstrated general trends present in the stream under storm flow versus base flow conditions and also highlighted the influence of increased effluent flow following rain in shifting the stream microbial community from abundant freshwater taxa to those more associated with urban/anthropogenic settings. Shifts in the taxonomic composition were also linked to changes in functional gene content, particularly for transmembrane transport and organic substance biosynthesis. We also observed an increase in relative abundance of genes encoding degradation of organic pollutants and antibiotic resistance after rain. Overall, this study highlighted some differences in the microbial community of an urban stream under storm flow conditions and showed the impact of a storm flow event on the microbiome from an environmental and public health perspective. IMPORTANCE Urban streams in various parts of the world are facing increased anthropogenic pressure on their water quality, and storm flow events represent one such source of complex physical, chemical, and biological perturbations. Microorganisms are important components of these streams from both ecological and public health perspectives. Analysis of the effect of perturbations on the stream microbial community can help improve current knowledge on the impact such chronic disturbances can have on these water resources. This study examines microbial community dynamics during rain-induced storm flow conditions in an urban stream of the Chicago Area Waterway System. Additionally, using shotgun metagenomics we identified significant shifts in the microbial community composition and functional gene content following a high-rainfall event, with potential environment and public health implications. Previous work in this area has focused on specific genes/organisms or has not assessed immediate storm flow impact.

Baseflow contribution to nitrates in an urban stream in Daejeon, Korea

2010 ◽  
Vol 61 (12) ◽  
pp. 3216-3220 ◽  
Author(s):  
G. Kim ◽  
H. Lee ◽  
Y. Lim ◽  
M. Jung ◽  
D. Kong
Keyword(s):  
Water Quality ◽  
Surface Water ◽  
Groundwater Quality ◽  
Stream Water ◽  
Surface Water Quality ◽  
Quality Data ◽  
Urban Stream ◽  
Hydrograph Separation ◽  
Stream Water Quality ◽  
The Impact

It is a well-known fact that baseflow discharge of rainfall runoff significantly impacts the quality of surface water. In this paper, the impact of nitrates discharged as baseflow on stream water quality were studied using PULSE, a hydrograph separation software developed by USGS, to calculate the monthly baseflow discharge. We took water quality and flow rate data from a monitoring station site (code: Ghapcehon2) in Daejeon city and acquired 2005 groundwater quality data in the watershed from government agencies. Agricultural and forestry land use are dominant in the area. The baseflow contributes 85%–95% of stream flows during the spring and fall, 25%–38% during the summer and winter. The monthly nitrate loading discharged as baseflow for Ghapcheon2 was estimated by using monitored nitrate concentrations of groundwater in the watershed. Nitrate loading induced by baseflow at Ghapcheon2 was estimated as 5.4 tons of NO3−-N/km2, which is about 60% of nitrate loading of surface water, or 9.2 tons of NO3−-N/km2. This study shows that groundwater quality monitoring is important for proper management of surface water quality.

Water quality and prospects for revitalization of an urban stream in Recife, Brazil

2020 ◽  
Vol 11 (5) ◽  
pp. 284-294
Author(s):  
José Luís Said Cometti ◽  
Jaime Joaquim da Silva Pereira Cabral ◽  
Taylse Marielly da Conceição
Keyword(s):  
Water Quality ◽  
Riparian Forest ◽  
Stream Water ◽  
Oxygen Demand ◽  
Urban Stream ◽  
The European Union ◽  
Stream Water Quality ◽  
Anthropogenic Pressures ◽  
Untreated Sewage ◽  
Lake Zone

The urbanization of Recife characterized an occupation of the Capibaribe River banks and its tributaries. This caused the grounding, rectification and degradation of several streams. Thus, this paper presents a diagnosis of the Cavouco stream water quality and suggests measures for its restoration. The collections were performed between 2016 and 2017 in three sampling points. Analysis adopted the Standard Methods for the Examination of Water and Wastewater and calculated the Water Quality Index (WQI). A correlation test between the parameters was applied to understand the phenomenon. Actions to revitalize it followed the European Union Water Framework Directive. The WQI of the Cavouco stream had a good presentation in the small lake zone; it was poor in the Federal University (UFPE) region and awful in the Caxangá Avenue section.  Dissolved Oxygen (OD) concentration was negatively correlated with Biochemical Oxygen Demand (BOD), decreasing from upstream to downstream.  Water quality degradation is associated with untreated sewage discharge along the stream. The proposal to its recovery is to collect and treat domestic sewage, remove irregular housing, restore the riparian forest, control erosion, create linear parks and search for governance mechanisms with public participation. The proposed interventions are fundamental for the restoration of Cavouco's ecological potential, with improved water quality and reduced anthropogenic pressures.

scholarly journals Managing Stormwater by Accident: A Conceptual Study

Water ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1492
Author(s):  
Carly M. Maas ◽  
William P. Anderson ◽  
Kristan Cockerill
Keyword(s):  
Urban Areas ◽  
Stream Water ◽  
Road Salt ◽  
Urban Environments ◽  
Transport Processes ◽  
Storm Event ◽  
Stream Water Quality ◽  
Stream Monitoring ◽  
Summer Storm ◽  
The Impact

Stormwater-driven road salt is a chronic and acute issue for streams in cold, urban environments. One promising approach for reducing the impact of road salt contamination in streams and adjacent aquifers is to allow “accidental wetlands” to flourish in urban areas. These wetlands form naturally as a byproduct of human activities. In this study, we quantified the ability of an accidental wetland in northwestern North Carolina, USA, to reduce the timing and peak concentration of road salt in a stream. Monitoring suggests that flow and transport processes through the wetland reduce peak concentrations and delay their arrival at the adjacent stream. We expand these findings with numerical simulations that model multiple meltwater and summer storm event scenarios. The model output demonstrates that small accidental wetland systems can reduce peak salinities by 94% and delay the arrival of saltwater pulses by 45 days. Our findings indicate that accidental wetlands improve stream water quality and they may also reduce peak temperatures during temperature surges in urban streams. Furthermore, because they find their own niche, accidental wetlands may be more effective than some intentionally constructed wetlands, and provide opportunities to explore managing stormwater by letting nature take its course.

scholarly journals Analyses of Spatial and Temporal Variations of Salt Concentration in Waterbodies Based on High Resolution Measurements Using Sensors

Hydrology ◽  
2021 ◽  
Vol 8 (2) ◽  
pp. 64
Author(s):  
Rohan Benjankar ◽  
Ravin Kafle ◽  
Shanti Satyal ◽  
Nirajan Adhikari
Keyword(s):  
Water Quality ◽  
High Resolution ◽  
Salt Concentration ◽  
Urban Stream ◽  
Sensor Technology ◽  
Road Maintenance ◽  
Spring Season ◽  
Parking Lot ◽  
Winter Road ◽  
Winter Road Maintenance

Studies have shown that salt concentrations are increasing in waterbodies such as lakes, rivers, wetlands, and streams in areas where deicers are commonly applied for winter road maintenance, resulting in degraded water quality. As the salt concentration varies spatially and temporally based on environmental and hydrological characteristics, we monitored high resolution (15 min) salt concentrations for a relatively long period (winter and spring season) at different sites (i.e., stream, urban-stream, roadside drain, and parking-lot drain) using multiple electric conductivity-based sensors. The salt concentrations were significantly different from each other considering individual sensors and different sites in both winter and spring seasons, which support past research results that concentration varies spatially. Parking-lot (1136 ± 674 ppm) and Roadside (701 ± 263 ppm) drain measured significantly higher concentration than for Stream (260 ± 60 ppm) and Urban-stream (562 ± 266 ppm) in the winter season. Similar trends were observed for the spring season, however, the mean concentrations were lower in the spring. Furthermore, salt concentrations were significantly higher during the winter (242 ± 47 ppm to 1695 ± 629 ppm) than for the spring (140 ± 23 ppm to 863 ± 440 ppm) season considering different sites, which have been attributed to the winter snow maintenance practice using deicers in past studies. All sites exceed the United States Environmental Protection Agency (USEPA) threshold (salt concentration higher than 230 mg/L) for chronic exposure level for 59% to 94% and 10% to 83% of days in winter and spring seasons, respectively. The study has highlighted the usefulness and advantages of high resolution (spatially and temporally) salt concentration measurement using sensor technology. Furthermore, the salt concentration in waterbodies can vary spatially and temporally within a small spatial scale, which may be important information for managing water quality locally. The high resolution measurements (i.e., 15 min) were helpful to capture the highest potential salt concentrations in the waterbody. Therefore, the sensor technology can help to measure high resolution salt concentrations, which can be used to quantify impacts of high salt concentrations, e.g., application of deicer for winter road maintenance on aquatic systems based on the criteria developed by USEPA.

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