Assessment of Infiltration from Private Sewer Laterals: Case Study in Jurmala, Latvia
Water 2022
Gints Dakša, Sandis Dejus, Jānis Rubulis

The presence of excess water in centralized sewerage systems is known to have a multitude of unfavorable effects on the daily operation of the wastewater infrastructure. The additional volume of I/I-water decreases the hydraulic capacity of wastewater collection networks, reduces the efficiency of wastewater treatment processes, and increases the costs of transporting and treating the wastewater. Currently, most I/I studies in Latvia are conducted on the scale of the wastewater treatment plant service area and determine only the common performance indicators for a given year. However, data of such resolution are not sufficient to identify problem areas within the networks and to introduce cost-effective measures. The contribution of private sewer laterals to the overall I/I volume is an area of particular interest. Although it is possible to locate and quantify I/I from individual house connections, in practice, given the financial and time constraints, it is not feasible to apply a case-by-case approach. Thus, a simple method to predetermine the problematic parts of the system before conducting on-site inspections is needed. This study investigates the link between groundwater levels and observed night-time wastewater flows on a sub-catchment scale by performing a linear regression analysis (940 data points in total). The results show a direct correlation (R > 0.70 in all cases) between said parameters and highlight the impacts of poorly built and ill-maintained house connections. The presented approach can be widely adopted by system operators to help identify potential sources of diluted wastewater and to aid in the development of priority-based renovation plans.


Keywords
excess water | groundwater | house connections | infiltration/inflow | laterals | private sewers | regression analysis
DOI
10.3390/w14182870
Hyperlink
https://www.mdpi.com/2073-4441/14/18/2870/htm

Dakša, G., Dejus, S., Rubulis, J. Assessment of Infiltration from Private Sewer Laterals: Case Study in Jurmala, Latvia. Water, 2022, Vol. 14, No. 18, Article number 2870. e-ISSN 2073-4441. Pieejams: doi:10.3390/w14182870

Publication language
English (en)
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