TY - JOUR
T1 - A comparative study between low- and high-tech methods for the detection and mitigation of illicit connections in stormwater systems
AU - Schilperoort, Remy
AU - Post, Johan
AU - Klootwijk, Martijn
AU - Hoefeijzers, Bas
AU - Hof, Arjo
AU - Palsma, Bert
AU - Leenen, Imke
AU - Makris, Konstantinos F.
AU - Langeveld, Jeroen G.
AU - More Authors, null
PY - 2023
Y1 - 2023
N2 - Illicit connections of wastewater to stormwater systems are the main drawback of separate sewer systems, as they lead to a direct discharge of untreated wastewater to the aquatic environment. Consequently, several inspection methods have been developed for detecting illicit connections. This study simultaneously applied several low- and high-tech methods for the detection of illicit connections in the same catchment (De Heuvel, the Netherlands). The methods included mesh wire screens for capturing coarse contamination, measurements of electroconductivity and temperature, sampling and quantification of Escherichia coli and extended-spectrum ß-lactamase-producing E. coli (ESBL-EC), DNA analysis via quantitative polymerase chain reaction for human-, dog-, and bird-specific fecal indicators, and distributed temperature sensing. Significant illicit connections could be identified using all methods. Nonetheless, hydraulic conditions and, predominantly, the sewage volume determine whether a misconnection can be detected by especially the low-tech methods. Using these results, the identified misconnections were repaired and biological and DNA analyses were repeated. Our results demonstrate that there were no changes in E. coli or ESBL-EC before and after mitigation, suggesting that these common markers of fecal contamination are not specific enough to evaluate the performance of mitigation efforts. However, a marked decrease in human wastewater markers (HF183) was observed.
AB - Illicit connections of wastewater to stormwater systems are the main drawback of separate sewer systems, as they lead to a direct discharge of untreated wastewater to the aquatic environment. Consequently, several inspection methods have been developed for detecting illicit connections. This study simultaneously applied several low- and high-tech methods for the detection of illicit connections in the same catchment (De Heuvel, the Netherlands). The methods included mesh wire screens for capturing coarse contamination, measurements of electroconductivity and temperature, sampling and quantification of Escherichia coli and extended-spectrum ß-lactamase-producing E. coli (ESBL-EC), DNA analysis via quantitative polymerase chain reaction for human-, dog-, and bird-specific fecal indicators, and distributed temperature sensing. Significant illicit connections could be identified using all methods. Nonetheless, hydraulic conditions and, predominantly, the sewage volume determine whether a misconnection can be detected by especially the low-tech methods. Using these results, the identified misconnections were repaired and biological and DNA analyses were repeated. Our results demonstrate that there were no changes in E. coli or ESBL-EC before and after mitigation, suggesting that these common markers of fecal contamination are not specific enough to evaluate the performance of mitigation efforts. However, a marked decrease in human wastewater markers (HF183) was observed.
KW - Bacteroides
KW - conductivity
KW - DTS
KW - E. coli
KW - ESBL-EC
KW - illicit connections
UR - http://www.scopus.com/inward/record.url?scp=85174486768&partnerID=8YFLogxK
U2 - 10.2166/wst.2023.309
DO - 10.2166/wst.2023.309
M3 - Article
C2 - 37830999
AN - SCOPUS:85174486768
SN - 0273-1223
VL - 88
SP - 1833
EP - 1846
JO - Water Science and Technology
JF - Water Science and Technology
IS - 7
ER -