Contribution of rooftop rainwater harvesting to climate adaptation in the city of Hannover: Water quality and health issues of rainwater storage in cisterns and ponds

authored by: Estefania Carpio-Vallejo, Urda Düker, Jessica Waldowski, Regina Nogueira
Abstract: Rooftop rainwater harvesting systems and blue-green infrastructure are becoming important resilience alternatives for urban climate adaptation. This study sheds light on the largely unreported physicochemical and microbiological quality of private roof-harvested rainwater (RHRW). We aimed to identify the physicochemical and microbiological characteristics of RHRW, explore potential correlations between them and assess probable health risks associated with recreational interactions of children with the water. RHRW was collected from cisterns and ponds located in an inner courtyard in Hanover, Germany. Physicochemical parameters were measured on site and samples were collected once a month in two campaigns in 2020 and 2021. Escherichia coli concentrations ranged from 1 × 10° to 24.1 × 10² MPN/100 mL, Enterococci from 1 × 10° to 19.7 × 10² MPN/100 mL, Salmonella from 1 × 10² to 39 × 10³ CFU/100 mL and Pseudomonas aeruginosa from 1 × 10° to 3 × 10³ MPN/100 mL. Correlation analysis indicated potential relationships between bacteria, oxygen, and water temperature. The results of the health risk assessment indicated a potential risk of gastrointestinal illnesses due to exposure to Enterococci and Salmonella spp. present in the cisterns and ponds, highlighting the need for appropriate regulations and guidelines for RHRW aimed for non-potable uses. Blue-green infrastructure, when effectively managed and maintained, can offer benefits both by enhancing urban climate resilience and promoting citizens well-being.
Organisation(s): Institute of Sanitary Engineering and Waste Management
External Organisation(s): Stadtentwässerung Hannover
Type: Article
Journal: International Journal of Hygiene and Environmental Health
ISSN: 1438-4639
Publication date: 03.2024
Publication status: Published
Peer reviewed: Yes
ASJC Scopus subject areas: Public Health, Environmental and Occupational Health
Sustainable Development Goals: SDG 3 - Good Health and Well-being, SDG 13 - Climate Action
Electronic version(s): https://doi.org/10.1016/j.ijheh.2024.114320 (Access: Open)

BibTeX

@article{3d47311a5aa84f1693374da231726484,
title = "Contribution of rooftop rainwater harvesting to climate adaptation in the city of Hannover: Water quality and health issues of rainwater storage in cisterns and ponds",
abstract = "Rooftop rainwater harvesting systems and blue-green infrastructure are becoming important resilience alternatives for urban climate adaptation. This study sheds light on the largely unreported physicochemical and microbiological quality of private roof-harvested rainwater (RHRW). We aimed to identify the physicochemical and microbiological characteristics of RHRW, explore potential correlations between them and assess probable health risks associated with recreational interactions of children with the water. RHRW was collected from cisterns and ponds located in an inner courtyard in Hanover, Germany. Physicochemical parameters were measured on site and samples were collected once a month in two campaigns in 2020 and 2021. Escherichia coli concentrations ranged from 1 × 10° to 24.1 × 102 MPN/100 mL, Enterococci from 1 × 10° to 19.7 × 102 MPN/100 mL, Salmonella from 1 × 102 to 39 × 103 CFU/100 mL and Pseudomonas aeruginosa from 1 × 10° to 3 × 103 MPN/100 mL. Correlation analysis indicated potential relationships between bacteria, oxygen, and water temperature. The results of the health risk assessment indicated a potential risk of gastrointestinal illnesses due to exposure to Enterococci and Salmonella spp. present in the cisterns and ponds, highlighting the need for appropriate regulations and guidelines for RHRW aimed for non-potable uses. Blue-green infrastructure, when effectively managed and maintained, can offer benefits both by enhancing urban climate resilience and promoting citizens well-being.",
keywords = "Blue-green infrastructure, Health risk assessment, Rainwater quality, Risk of illness, Roof-harvested rainwater, Urban resilience",
author = "Estefania Carpio-Vallejo and Urda D{\"u}ker and Jessica Waldowski and Regina Nogueira",
note = "Funding Information: Overall, our study revealed negative correlations between dissolved oxygen and FIB across the sampled locations, which is consistent with the findings reported by Nnaji and Nnam (2019) suggesting that microbial activities contribute to a significant decrease in oxygen availability in water. Furthermore, we observed negative correlations between water temperature and oxygen levels, indicating that oxygen solubility decreases with an increase in temperature, as supported by previous studies (Bozorg-Haddad et al., 2021).This research was funded by the Federal Ministry of Education and Research (BMBF) within the RES:Z call: Resource-optimized city of the future; research project TransMiT—Resource-optimized transformation of combined and separate drainage systems in existing quarters with high population pressure, Subproject Effect of BGI on local climate/backyards, grant number 033W105A UP5. We are grateful to Ms. Claudia Helle for her assistance during lab work, Ms. Franziska Meyer and Ms. Zora Treiber for their contribution during sampling and field observations. Funding Information: This research was funded by the Federal Ministry of Education and Research (BMBF) within the RES:Z call: Resource-optimized city of the future; research project TransMiT—Resource-optimized transformation of combined and separate drainage systems in existing quarters with high population pressure, Subproject Effect of BGI on local climate/backyards, grant number 033W105A UP5 . We are grateful to Ms. Claudia Helle for her assistance during lab work, Ms. Franziska Meyer and Ms. Zora Treiber for their contribution during sampling and field observations. ",
year = "2024",
month = mar,
doi = "10.1016/j.ijheh.2024.114320",
language = "English",
journal = "International Journal of Hygiene and Environmental Health",
issn = "1438-4639",
publisher = "Urban und Fischer Verlag Jena",
number = "256",
}