EFFECT OF GREEN ROOF AGE ON RUNOFF WATER QUALITY IN PORTLAND, OREGON

2018 ◽  
Vol 13 (2) ◽  
pp. 42-54 ◽  
Author(s):  
Jarrett Okita ◽  
Cara Poor ◽  
Jessica M. Kleiss ◽  
Ted Eckmann
Keyword(s):  
Water Quality ◽  
Urban Areas ◽  
Water Retention ◽  
Green Roof ◽  
Green Roofs ◽  
Dry Season ◽  
Rain Event ◽  
Wet Season ◽  
Runoff Water

Green roofs have become a common method to increase water retention on-site in urban areas. However, the long-term water quality of runoff from green roofs is poorly understood. This study evaluated the water quality of stormwater runoff from a regular (non-vegetated) roof, a green roof installed 6 months previously, and a green roof installed 6 years ago in Portland, Oregon. Samples of runoff were taken during every rain event for 10 months, and analyzed for total phosphorus (TP), phosphate (PO3-4), total nitrogen (TN), nitrate (NO-3), ammonia (NH3), copper (Cu), and zinc (Zn). Runoff from the green roofs had higher concentrations of TP and PO3-4 and lower concentrations of Zn compared to the regular roof. Average TP concentrations from the 6-year old roof and 6-month old roof were 6.3 and 14.6 times higher, respectively, than concentrations from the regular roof, and average PO3-4 concentrations from the 6-year old roof and 6-month old roof were 13.5 and 26.6 times higher, respectively, compared to the regular roof. Runoff from the 6-month old green roof had higher concentrations of TP and PO3-4 than the 6-year old green roof during the wet season, but lower concentrations during the dry season. The 6-month old green roof installations where receiving waters are sensitive or impaired may need additional treatment methods to reduce phosphorus levels. As green roofs age, water retention decreases and phosphorus leaching increases during the dry season.

Assessing Rainwater Quality Treated via a Green Roof System

2021 ◽  
Author(s):  
Thomas Schatzmayr Welp Sá ◽  
Mohammad K Najjar ◽  
Ahmed W A Hammad ◽  
Elaine Garrido Vazquez ◽  
Assed Naked Haddad
Keyword(s):  
Water Quality ◽  
Experimental Study ◽  
Green Roof ◽  
Green Roofs ◽  
Ammonia Nitrogen ◽  
Rain Event ◽  
Water Crisis ◽  
Roof System ◽  
Rainwater Quality

Abstract The shortage of water worldwide is increasingly worrying. Studies in the field suggest that sustainable water resource management via water recycling is fundamental to alleviate the issue. The use of rainwater is an important alternative source that must be considered, mainly, in the water crisis facing the planet. When integrated with the concept of green roofs, the capturing and treatment of rainwater in these structures becomes an even more ecological and sustainable practice. The water drained by the roof can be used for non-potable uses, such as flushing toilet bowls. One of the main concerns when using rainwater, even for non-potable uses, is the quality of the water available, so as not to put users' health at risk. In this way, the present work proposes to experimentally analyze the quality of rainwater drained in a green roof prototype for reuse purposes. The green roof prototype was installed on an experimental bench. After each rain event (four in total), two water samples were collected in the following situations: rainwater captured directly by a container next to the bench, and rainwater drained by the green roof prototype, captured by a container through existing drains at the base of the prototype. The analyzes of the collected samples were carried out at the Environmental Engineering Laboratory (LEMA / UFRJ) and performed according to the Standard Methods for the Examination of Water and Wastewater. Specifically, the experiments examine physicochemical and biological parameters following a rain event on a green roof prototype for sanitary use. Experimental results that were observed and analyzed include color, turbidity, pH, ammonia nitrogen, nitrite, nitrate, orthophosphate, total coliforms, and thermotolerant coliforms to indicate the rainwater quality from green roofs. The majority of parameters assessed were within the value thresholds indicated by the Brazilian standards, while the results of orthophosphate, fecal coliforms, color, and turbidity were not. The greatest divergence is in the concentration of orthophosphate, where a concentration of 10.88mg/L was obtained in this experimental study while other authors present values ​​of 0.1 and 0.01mg/L. Total coliforms also presented high values, but within the expected range. Comparisons with technical documents and international references related to water quality to identify possibilities of the use of rainwater were also conducted. Results indicate that the water quality has the same order of quantity for turbidity, nitrite, and ammonia nitrogen parameters across the standards. Based on such observations, filtration and disinfection processes are therefore required in the green roof system for the use of rainwater for sanitary. Finally, the experimental study of rainwater quality on the green roof presented similar results comparing with international references. The use of green roofs combined with the use of rainwater demonstrates the potential and benefits as an alternative to face the water crisis.

Assessing P fertiliser use in vegetable production: agronomic and environmental implications

Soil Research ◽  
2010 ◽  
Vol 48 (8) ◽  
pp. 674 ◽  
Author(s):  
K. Y. Chan ◽  
T. Wells ◽  
D. Fahey ◽  
S. M. Eldridge ◽  
C. G. Dorahy
Keyword(s):  
Water Quality ◽  
Urban Areas ◽  
Management Practices ◽  
Poultry Litter ◽  
Vegetable Production ◽  
Environmental Implications ◽  
Runoff Water ◽  
Soil P ◽  
Farming Practice

Vegetable production is often located in the peri-urban areas close to large cities. In Sydney, Australia, excessive levels of phosphorus (P) have been reported in the soils, and vegetable farms have long been regarded as a potential source of the P that enters Sydney’s waterways. We report vegetable production under varying soil P conditions and the consequent changes in soil P, as well as water quality of runoff and leachate after growing 5 crops in a field trial where inputs in the form of garden organic compost were compared to current farmers’ practice. No difference in vegetable yield was observed between 100 and 400 mg/kg of soil Colwell P (0–0.10 m); therefore, our results indicate that the excessive soil P levels in the vegetable farms around Sydney are not important for optimal vegetable production. Results from runoff and leachate studies clearly demonstrate that high concentrations of P in soils used for vegetable production under the current farming practice around Sydney have increased the potential to export P and to negatively affect water quality of receiving environments. The significant increases in soluble P concentrations found in the soil and runoff water from the current farming practice can be attributed to the use of poultry litter. In contrast, using compost in place of poultry litter resulted in significantly reduced soil P accumulation and P concentration in runoff and leachate. Training and education programs for farmers and their advisors are recommended to encourage more sustainable fertiliser management practices and reduce the accumulation of P in the environment.

scholarly journals Assessment of heavy metal and physico-chemical pollution loadings of River Benue water at Makurdi using water quality index (WQI) and multivariate statistics

2021 ◽  
Vol 11 (7) ◽  
Author(s):  
Raphael Terungwa Iwar ◽  
Joseph Terlumun Utsev ◽  
Martina Hassan
Keyword(s):  
Water Quality ◽  
Heavy Metal ◽  
Water Quality Index ◽  
Quality Index ◽  
Dry Season ◽  
Pollution Monitoring ◽  
Total Variance ◽  
Wet Season ◽  
Physico Chemical

AbstractIn this work, the quality of River Benue water at Makurdi was assessed for its heavy metal load alongside seven other physico-chemical parameters using water quality index (WQI) and multivariate statistical tools. A total of 45 samples from three (3) different points along the River course were collected for five months (October 2018–May, 2019) spanning the dry and wet seasons. Samples were analysed  in accordance with standard methods. Most of the parameters evaluated were found to fall in the allowable limits of the World Health Organization (WHO) among others, except for colour, turbidity, total suspended solids, nickel, lead and cadmium. WQI analysis using the BISWQI, OWQI and CCMEWQI indicated that all indexing methods were suitable for estimating the WQI of River Benue as they all showed that the water corresponded to the classification as “poor water”. Heavy metal index of the river ranged from13.40–6080.00 and from 47.07–7240.00 for the dry and wet seasons, respectively, and was majorly influenced by high cadmium and lead pollution levels. Principal component analysis (PCA) revealed three rotated factor with respective communality levels for both the dry and wet seasons. Factor 1 was positively loaded with nine parameters which accounted for 32.3% of the total variance during the dry season, while it was positively loaded with 10 parameters in the wet season accounting for 25.9% of total variance. Hierarchical cluster analysis (HCA) revealed that the river was zoned into four clusters each for both dry and wet seasons. Sampling points 2 and 3 were the most polluted during the dry season, while sampling point 1 was found to be the most polluted in the wet season. It was concluded that the increasing and diverse nature of anthropogenic activities on the river course was responsible for the deteriorating quality of the water. The study recommended continuous pollution monitoring and local regulations to reduce the entrance of both diffuse and point source pollution into the river.

scholarly journals Are Biocrusts and Xerophytic Vegetation a Viable Green Roof Typology in a Mediterranean Climate? A Comparison between Differently Vegetated Green Roofs in Water Runoff and Water Quality

Water ◽  
2021 ◽  
Vol 13 (1) ◽  
pp. 94
Author(s):  
Bernardo Rocha ◽  
Teresa A. Paço ◽  
Ana Catarina Luz ◽  
Paulo Palha ◽  
Sarah Milliken ◽  
...  
Keyword(s):  
Water Quality ◽  
Drinking Water ◽  
Green Roof ◽  
Green Roofs ◽  
Water Runoff ◽  
The European Union ◽  
Impact Of Urbanization ◽  
Health Organization ◽  
Almost All

Green roofs can be an innovative and effective way of mitigating the environmental impact of urbanization by providing several important ecosystem services. However, it is known that the performance of green roofs varies depending on the type of vegetation and, in drier climates, without resorting to irrigation, these are limited to xerophytic plant species and biocrusts. The aim of this research was therefore to compare differently vegetated green roofs planted with this type of vegetation. A particular focus was their ability to hold water during intense stormwater events and also the quality of the harvested rainwater. Six test beds with different vegetation compositions were used on the roof of a building in Lisbon. Regarding stormwater retention, the results varied depending on the composition of the vegetation and the season. As for water quality, almost all the parameters tested were higher than the Drinking Water Directive from the European Union (EU) and Word Health Organization (WHO) guidelines for drinking-water quality standards for potable water. Based on our results, biocrusts and xerophytic vegetation are a viable green roof typology for slowing runoff during stormwater events.

scholarly journals Benthic macroinvertebrates diversity as bioindicators of water quality of Nasarawa Reservoir Katsina State Nigeria

2020 ◽  
Vol 12 (1) ◽  
pp. 449-456
Author(s):  
Zahraddeen Hassan Yusuf
Keyword(s):  
Water Quality ◽  
Benthic Macroinvertebrates ◽  
Working Party ◽  
Dry Season ◽  
Wet Season ◽  
Quality Of Water ◽  
Physico Chemical ◽  
Invertebrate Population ◽  
Number Of Individuals

This study was carried out to assess the water quality of Nasarawa using benthic macroinvertebrates as bioindicators. Biological monitoring working party (BMWP) scoring system was the index used to assess the ecosystem health of Nasarawa reservoir. A total of 4460 macrobenthic invertebrate comprising three phyla, three classes, six families and seventeen species were recorded. The overall macrobenthic population at the different stations revealed that the study area was dominated by Mollusca (41.18%), Oligochaetae (23.53%), Coleoptera and Diptera (11.77%), Mollusca (29.06%), Ephemerophtera and Odonata (5.89%). (BMWP) score of 65.7 was obtained for Nasarawa reservoir which classifies the reservoir as moderately polluted. Higher BMWP score of 65.7 was recorded in the wet season compared to the dry season value of 58.7. More macrobenthic invertebrate population was recorded in the dry season than in the wet season in Nasarawa reservoir. Simpson (1-D), Shannon (H) and evenness were higher during the dry season than in the wet season but dominance was higher in the wet season. Species richness as revealed by the Margaleff and Menhinick index was higher during the wet season than in the dry season. The variations in taxa and number of individuals during the months of sampling was not significantly different (P>0.05). It was found that agricultural activities, washing and bathing could alter physico-chemical parameters of the stream and hence changing the abundance of macroinvertebrates as well as the quality of water. This study, therefore, recommends that the source of pollutants should be controlled and the stream regularly monitored by the relevant authorities. Keywords: Benthic macroinvertebrates, Bioindicator, Water quality, Reservoir

scholarly journals GREEN ROOFS TO IMPROVE THE ENERGY RENOVATION RESILIENCE OF HISTORIC BUILDINGS

2019 ◽  
Vol 6 (1) ◽  
Author(s):  
Giovanni Santi ◽  
Sara Battini
Keyword(s):  
Urban Areas ◽  
Green Roof ◽  
Green Roofs ◽  
Energy Performance ◽  
Historic Buildings ◽  
Existing Building ◽  
Technical Issues ◽  
The Moment ◽  
Green System

The introduction of vegetation in urban areas, through both green roofs and green walls, is a sustainable strategy for improving the environment and the quality of life, as well as crucial for urban biodiversity since the moment it is able to create new habitats for plant and animal species. The design and realization of green roof systems abroad is promoted and stimulated while in Italy, this subject, is still an innovation not supported by many real implementations. The application of this technological green system has a great importance for the redevelopment of existing building heritage, especially for historic buildings, to improve their energy-performance qualities, with respect for their architectural value. The aim of this study is to identify the technical issues for the realization of green roofs in urbanized contexts by focusing on the implementation of a green roof on a building of Leghorn following intervention guidelines developed. This research shows that not only does this system allow higher energy saving, but it also brings a decrease of load bearing on the structure.

scholarly journals Effect of Green Roof Configuration and Hydrological Variables on Runoff Water Quantity and Quality

Water ◽  
2018 ◽  
Vol 10 (7) ◽  
pp. 960 ◽  
Author(s):  
Pascual Ferrans ◽  
Carlos Rey ◽  
Gabriel Pérez ◽  
Juan Rodríguez ◽  
Mario Díaz-Granados
Keyword(s):  
Water Quality ◽  
Vegetation Cover ◽  
Green Roof ◽  
Oxygen Demand ◽  
Substrate Type ◽  
Runoff Water ◽  
Rainfall Events ◽  
Modular Systems ◽  
Hydrological Variables

Green roofs (GRs) are a feasible solution for mitigating increased runoff volumes in urban areas. Though many studies have focused their analysis on the quantity and quality of GR runoff, with respect to the relevance of specific site conditions in GR performance, the information gathered for the tropical Andes is not sufficient. This study assessed the hydrological performance and runoff water quality of 12 green roof modular systems located at the Universidad de los Andes campus (Bogotá, Colombia). Based on 223 rainfall events spanning a 3-year period, average rainfall retention was 85% (coefficient of variation = 29%). t-tests, the Welch Test, multiple linear regressions, and correlation analysis were performed in order to assess the potential effect of air temperature, substrate type, vegetation cover, relative humidity, antecedent dry weather period (ADWP), rainfall duration, and rainfall maximum intensity. In some cases, GR design variables (i.e., substrate type and vegetation cover) were found to be significant for describing rainfall retention efficiencies and, depending on the GR type, some hydrological variables were also correlated with rainfall retention. Rainfall and GR runoff from 12 rainfall events were also monitored for total Kjeldahl nitrogen (TKN), nitrates, nitrites, ammonia, total phosphorus (TP), phosphates, pH, total dissolved solids (TDS), total suspended solids (TSS), color, turbidity, biological oxygen demand (BOD), chemical oxygen demand (COD), total coliforms, metals (i.e., zinc, copper, nickel, lead, selenium, aluminum, barium, boron, calcium, strontium, iron, lithium, magnesium, manganese, potassium, sodium), and polyaromatic hydrocarbons (PAHs). The results obtained confirmed that GR systems have the ability to neutralize pH, but are a source of the rest of the aforementioned parameters, excluding PAHs (with concentrations below detection limits), ammonia, TSS, selenium and lithium, where differences with control cases (rainfall and plastic panel runoff) were not statistically significant. Substrate type, event size, and rainfall regime are relevant variables for explaining runoff water quality.

scholarly journals EVALUATING FUTURE WATER QUALITY OF URBAN RIVERS IN HANOI UNDER EFFECT OF URBANIZATION AND CLIMATE CHANGE - THE APPLICATION OF WEAP MODEL FOR CAU BAY RIVER

2020 ◽  
Vol 58 (3A) ◽  
pp. 195
Author(s):  
Lan Huong Nguyen ◽  
Viet Nga Thi Tran
Keyword(s):  
Climate Change ◽  
Water Quality ◽  
Treatment Plant ◽  
Dry Season ◽  
Capital City ◽  
Master Plan ◽  
Urban Rivers ◽  
Water Drainage ◽  
Wet Season

Every day, up to 750,000 cubic meters of wastewater in Hanoi metropolitan areas is discharged directly into rivers and lake, of which only 10% is treated to the Vietnamese standards. According to the water drainage development master plan for the capital city of Hanoi until 2030, the government aim at dealing with flooding and improve environmental sanitation for local residents. With respect to the baseline and Master plan implementation scenarios, this study evaluates the future water quality of urban rivers in Hanoi under the effect of urbanization and climate change using Water Evaluation And Planning tool (WEAP) and take the Cau Bay catchment as the case study. The result shows that, without implementation of wastewater treatment plant, the water quality of Cau Bay River will be worse with the DO in dry season is 0.2-1.2 mg/l and BOD is 52.0-55.0 mg/l. With the implementation of Master plan, the level of DO and BOD would be 7.1-7.3 mg/l and 7.0-13.8 mg/l respectively in the dry season whereas the values are 3.7 mgO/l and 36.1-41.8 mg/l in the wet season. The degradation of wastewater during the wet season is results from the combine- overflow sewage system as designed in the master plan.

scholarly journals Evaluating Water Quality Variation in the Vietnamese Mekong Delta Area Using Cluster and Discriminant Analysis

2020 ◽  
pp. 14-27
Author(s):  
Giao Thanh Nguyen ◽  
Huynh Thi Hong Nhien
Keyword(s):  
Water Quality ◽  
Discriminant Analysis ◽  
Rainy Season ◽  
Mekong Delta ◽  
Water Quality Monitoring ◽  
Temporal Variations ◽  
Dry Season ◽  
Wet Season ◽  
Monitoring Cost ◽  
Runoff Water

The study aims to assess spatial and temporal water quality variations in the upper reaches of the Vietnamese Mekong Delta. Thirty-one water monitoring samples of the two main rivers (Tien and Hau Rivers) and six canals flowing through An Giang Province were collected in the dry season (March) and the rainy season (September) from 2009 to 2019. Seven physicochemical parameters were analyzed including temperature, pH, dissolved oxygen (DO), biochemical oxygen demand (BOD), total suspended solids (TSS), orthophosphate (P-PO43-), and coliforms. Water quality index (WQI), cluster analysis (CA), and discriminant analysis (DA) were applied to evaluate water quality, spatial and temporal variations, and seasonal discriminant water variables. WQI values (15–71) indicated surface water quality was very bad to medium in which the water quality in larger and in smaller rivers in the dry season was less polluted than that in the rainy season due to erosion and runoff water containing waste materials in the wet season. CA grouped the water quality in the dry and rainy seasons into four clusters mainly due to BOD and coliforms in the dry season; TSS and coliforms in the rainy season. Discriminant analysis revealed that DO, TSS, coliforms, temperature and BOD significantly contributed to seasonal variations in water quality. Therefore, water quality monitoring in the surveyed area could only focus on DO, TSS, coliforms, temperature and BOD to reduce monitoring cost.

The use of reactive material for limiting P-leaching from green roof substrate

2016 ◽  
Vol 73 (12) ◽  
pp. 3027-3032 ◽  
Author(s):  
Agnieszka Bus ◽  
Agnieszka Karczmarczyk ◽  
Anna Baryła
Keyword(s):  
Water Quality ◽  
Urban Areas ◽  
Water Retention ◽  
Green Roof ◽  
Column Experiment ◽  
Phosphorus Concentration ◽  
Reactive Material ◽  
Average Value ◽  
Supporting Layer ◽  
P Leaching

Abstract The aim of the study is to assess the influence of drainage layer made of reactive material Polonite® on the water retention and P-PO4 concentration in runoff. A column experiment was performed for extensive substrate underlined by 2 cm of Polonite® layer (SP) and the same substrate without supporting layer as a reference (S). The leakage phosphorus concentration ranged from 0.001 to 0.082 mg P-PO4·L−1, with average value 0.025 P-PO4·L−1 of S experiment and 0.000–0.004 P-PO4·L−1 and 0.001 P-PO4·L−1 of SP experiment, respectively. The 2 cm layer of Polonite® was efficient in reducing P outflow from green roof substrate by 96%. The average effluent volumes from S and SP experiments amounted 61.1 mL (5.8–543.3 mL) and 46.4 mL (3.3–473.3 mL) with the average irrigation rate of 175.5 mL (6.3–758.0 mL). The substrate retention ability of S and SP experiments was 65% and 74%, respectively. Provided with reactive materials, green roof layers implemented in urban areas for rain water retention and delaying runoff also work for protection of water quality.

Sign in / Sign up

Export Citation Format

Share Document