Study on Drinking Water Distribution System at Sekaran District Service Area in Lamongan Regency

Drinking Water Supply System (SPAM) organizers needs to carry out its duties and functions to fulfil the quality, quantity, and continuity for the community. From all SPAM service areas in Sekaran District, there are three villages, namely Manyar, Jugo, and Trosono Village which lack access to water. The three villages water pressure falls below the minimum pressure requirements of Minister of Public Works and Housing Regulation Number 27/RT/M/2016. Seeing that the continuity is not optimal, it is important to study the drinking water distribution network of one of the SPAM in District Sekaran service areas. Recommendations for pipeline network restoration involves conducting hydraulic simulation using EPANET 2.2 which identified the need to parallelize existing pipes and establish a new pipe with a diameter of 200 mm and a length of 1960 m that connects Ngarum Village and Jugo Village. In addition, expanded reservoir capacity is required to meet water demand because it will increase during the development year. Furthermore, based on the results of the demand pattern measurement, the pump schedule must be modified, as well as the quantity of functioning pumps to be able to meet the water supply demand when the development occurs.


Introduction
Drinking water is essential for the sustenance of life and serves as a fundamental component utilized by nearly all living organisms to facilitate their diverse biological processes [1].Therefore, it is imperative to carefully consider the methodologies employed in the provision of water to consumers.The water distribution network is a crucial infrastructure system that plays a significant role in enhancing social welfare, fostering economic growth, and safeguarding public health.Hence, a water supply system is designed to consistently deliver water at an adequate pressure over its operational lifespan, ensuring the water flows delivered uninterruptedly to the point of consumption or end-user [2].
The Water Treatment Plant (WTP) in Sekaran District, Lamongan Regency, plays a crucial role in facilitating the provision of clean water to the local people.As of February 2023, the WTP has a production capacity of 83 L/s and caters to a clientele of 4,248 houses.The services provided by the WTP are distributed over four districts: Sekaran, Babat, Maduran, and Widang District.These districts are all located within the administrative region of Lamongan Regency, except for Widang District, which is under the administrative territory of Tuban Regency.
Nevertheless, it has been observed that residents of Manyar Village, Jugo Village, and Trosono Village, located in the Sekaran District, experience intermittent water delivery, particularly during periods of heightened water demand, across several service sectors.Furthermore, apart from the issue 1307 (2024) 012015 IOP Publishing doi:10.1088/1755-1315/1307/1/012015 2 of inadequate water supply to the residents, the three villages also encounter water pressure levels that fall below the standards outlined in Minister of Public Works and Public Housing Regulation No. 27/PRT/M/2016, which pertains to the execution of drinking water distribution systems [3].
The performance of the drinking water supply system, known as SPAM after Indonesian acronym, is required to meet specific standards as outlined in Indonesia Government Regulation Number 122 of 2015 concerning the Development of Drinking Water Supply Systems [4].This encompasses the assurance on the quantity, quality, and continuity of the potable water supply.The quantity and continuity of water supply should be sufficient to meet the daily demand for drinking water and ensure uninterrupted availability throughout the day.In the context of the community, it is imperative that the quality of drinking water generated adheres to the relevant regulations and standard.The quality criteria for drinking water in Indonesia are governed by the Regulation of the Minister of Health of the Republic of Indonesia Number 2 of 2023 [5].
In the capacity of an organizer for the Drinking Water Supply System, SPAM in Sekaran District is responsible for executing its obligations and roles in order to ensure the provision of drinking water to the community in terms of quantity, quality, and continuity.Given the suboptimal state of continuity, it is imperative to conduct a comprehensive study of the drinking water distribution network at SPAM in Sekaran District.The objective of this study is to offer recommendations for addressing water distribution issues within the designated service areas.In order to ensure the fulfillment of the water distribution system in terms of quality, quantity, and continuity, it is imperative to identify the underlying causes of any issues that may arise.This understanding is crucial for effectively and efficiently determining appropriate solutions and strategies for addressing these issues.

Data
The essential data obtained encompassed primary data, which consisted of geographical circumstances and demand pattern.Demand pattern is measured by the utilisation of a flow metre that is mounted and operated for a continuous duration of 24 hours on the pump discharge pipe.The pattern is essential in hydraulic modeling utilizing EPANET 2.2, a water modeling tool produced by United States Environmental Protection Agency (EPA).In addition to primary data sources, secondary data sources were utilized in this study.These sources encompassed a pipeline network map, demographic data, social facilities information, number of customers, elevation data, monthly water usage reports, pump specifications and schedules, as well as reservoir dimensions and specifications.

Methods
The study encompasses a range of tasks, including the collecting of primary and secondary data, determination of water demand, the projection of population and social facility, the projection of water demand, hydraulic simulation using EPANET 2.2, and the analysis of reservoirs.The determination of domestic water demands is conducted by utilising monthly reports on customer water use data in order to derive an average water demand.While the determination of non-domestic water needs is obtained upon the guidelines set forth by the Directorate General of Human Settlement within the Minister of Public Works and Public Housing.Once the water demands is determined, subsequent projections are generated.
Projections pertaining to population, social facility, and water demand have been computed for the next 10 years, for the year 2033.The population and social facility data was obtained from the publication of Indonesia Central Bureau of Statistics.The projection of population is conducted through the utilization of arithmetic, geometric, and least square methods.The selected method is the one that has a correlation coefficient (r) value closest to 1.The calculation of projected facilities can be conducted by the utilization of a population comparison methodology.The projected water demands include residential or domestic water demands, non-domestic water demands, and an estimation of water loss due to leakage.The estimation of domestic water consumption is derived from population predictions.In the interim, non-domestic water demands are derived from estimations based on social infrastructure.The estimation of water leakage is conducted based on the average leakage percentage provided by the SPAM of Sekaran.This involves multiplying the leakage percentage by the total water demand for both domestic and non-domestic purposes.
The utilization of hydraulic simulation using EPANET 2.2 and the analysis of reservoir capacity is employed in order to evaluate the current network system.The analysis of water pressure and water velocity is conducted in the pipeline network model that was developed using EPANET 2.2.EPANET analyze the movement of water within a network.It enables the tracking of water flow, pressure levels at various points in the network, as well as the simulation of chemical concentration and water age [6].This analysis involves utilizing the recorded water demand or peak hour factor, followed by the adjusting the pipe criteria in accordance with Indonesia Minister of Public Works and Public Housing Regulation Number 27/PRT/M/2016.The analysis of reservoir capacity is conducted in accordance with the guidelines outlined in Indonesia National Standard (SNI) 7509:2011, which pertains to the procedural aspects of engineering planning for distribution networks and service units within drinking water supply systems using tabulation method measured in cubic meters (m 3 ) [7].The evaluation results are afterwards used to ascertain the development planning of the water supply system within the designated service areas.

Water Demand/Consumption Unit
The production capacity of the WTP in Sekaran District is reported to be 83 L/s, while the number of consumers it serves as of February 2023 is at 4,248.The clients are classified into two distinct categories: tariff 01, which pertains to non-domestic sector, and tariff 02, which is domestic sector.Table 1 displays the service coverage and customer count details.Water demands can be categorized into two distinct categories: domestic water demands and nondomestic water demands.The determination of domestic or residential water demand is derived from an analysis of water consumption data for the month of February 2023, taking into account an average occupancy rate of 5 individuals per standard residence.According to the monthly water usage report of the SPAM, the water consumption in February 2023 amounted to 51,799 m 3 , which is approximately equivalent to a rate of 19.98 L/s.Table 2 presents the residential water demand for the service area of SPAM in Sekaran District.The SPAM services encompasses various non-domestic water demand, such as those pertaining to educational institutions, mosques, prayer rooms, auxiliary health clinics, village health centers, village offices, hamlet halls, cemeteries, parks, and foundations.This analysis exclusively focused on public facilities, hence excluding graves, gardens, and foundations as outliers.

Current Network
The current network employs a combined distribution system that integrates both gravity-based and pump-based methods.There are a total of four pumps, with two pumps allocated for the Taji Village service area and the remaining two pumps designated for serving twelve villages.At present, the services in Taji Village are reliant on a gravity-based system, resulting in the operation of only two pumps.The pump operation schedule is presented in the Table 3.The initial step in the analysis of the existing water distribution system involves the utilization of EPANET 2.2 software.This process entails the creation of a junction or node, followed by the input of relevant data such as elevation, demand pattern, and base demand.The determination of base demand is contingent upon the water demand derived from the monthly water usage report for the month of February 2023.The demand pattern refers to the temporal variations in water consumption within a given time period, often measured on an hourly or sub-hourly basis, in the context of water distribution systems [8].In order to ascertain the demand pattern, the flow is measured with flow meter installed on the pump discharge pipe.The obtained measurements indicate that the mean flow rate on weekdays is 20.38 L/s, with a maximum discharge rate of 33.90 L/s observed at 17:00.The determination of the demand pattern utilized in the analysis of the current distribution system is based on the recorded data and subsequent calculation of the multiplier, as presented in Table 4.

Forecasting population, public facilities, and water demand
Population projections are conducted in order to ascertain the anticipated rate of population growth and the projected population figures for the forthcoming decade.Among the three different ways, namely the geometric, arithmetic, and least square methods, the preferred approach is determined by selecting the method that exhibits the highest correlation coefficient (r) value which is closest to 1.The correlation analysis utilized a five-year time series dataset spanning from 2015 to 2019.The dataset is derived from the published reports of the Central Bureau of Statistics [9][10][11][12][13].The obtained correlation value for Simorejo Village indicates a negative correlation.This phenomenon may be attributed to a decline in the population.Therefore, the population of Simorejo Village is considered unchanged from the previous year.
The process of projecting social facilities involves assessing the anticipated water requirements for these facilities within their respective service regions, up until the designated projection year, which in this instance is 2033.In the context of development planning.the focus lies on the addition of facilities to ensure the provision of comprehensive service coverage within the designated area, rather than projecting their future requirements.The objective is to achieve optimal utilization and accessibility of all facilities, aiming for a 100% service coverage rate.This phenomenon can be attributed to the consistent number of facilities in the domains of education, health, and religion, as indicated by the statistics provided by Central Bureau of Statistics.
The term "domestic consumption unit" pertains to the water demands per individual per day.as indicated in Table 2, with a value of 82.18 L/person.day.In the context of non-domestic water demands.the term "non-domestic demands" pertains to the water needs of Category V (Villages) as defined by the Directorate General of Cipta Karya.These needs primarily encompass religious, health, and educational facilities.excluding Islamic boarding schools.The consumption unit of the Islamic boarding school adheres to the guidelines outlined in SNI 03-7065-2005.which pertains to the planning procedures for plumbing systems [14].According to this standard, the recommended water consumption per resident per day is 120 Liters.The consumption unit for the village office and hamlet hall pertains to the water usage report for February 2023, specifically indicating a consumption rate of 296.97 Liters per unit per day for the village office and 50 Liters per unit per day for the hamlet hall.
According to the SPAM of Sekaran District development plan, there is no comprehensive strategy for expansion and development of the service area.The primary aim is to solely concentrate on the augmentation of service percentage within the current service areas.The SPAM aims to achieve a monthly increase of 2 domestic customers.Therefore, the yearly rate of client increase amounts to 0.56%.Table 5 displays the outcomes of the anticipated water demand.

Development Planning
The water flow utilized in the network development plan for the year 2033 pertains to the estimation of water demands during that period.The demand pattern utilized is indicated in Table 3.In order to adequately fulfill the water demands, modifications have been implemented in the operational schedule of pumps.These alterations includes extending the running hours of distribution pumps and modifying the pipeline network through the installation of new pipes and the incorporation of parallel pipes.Table 6 presents the recommendations for the pipe network.The establishment of an extra pipe connection, specifically Pipe 84, is necessary to facilitate the link between Ngarum Village and Jugo Village.Pipe 84, which possesses a diameter of 200 mm, serves as a conduit linking the junctions J-27 and J-55.Furthermore, in order to establish connections between the pipes, supplementary pipes are positioned in parallel with the preexisting ones.The primary objective of implementing parallel pipe configuration is to effectively distribute the pressure and mitigate the occurrence of head loss inside the pipe system.In terms of resilience, the utilization of the parallel pipe strategy is found to be better than increasing the pipe size approach.An additional pipe is added in parallel to the existing pipe within the specific segment.This intervention consequently leads to a reduction in velocity and an increase in nodal pressure within the water distribution network [15].
In the context of pumping, it is necessary to use two pumps simultaneously, which were previously operated in an alternating manner, in order to fulfill the desired capacity.An additional pump is necessary to serve as a backup, given the current presence of two pumps.Recommendations pertaining to pumps and networks can be seen in Table 7.According to these regulations, the minimum pressure is 0.5 bar.which converts to 5.09 m.However, not all pipelines meet the speed requirements of 0.3 m/s -2.5 m/s, particularly the dividing pipes.The velocity can be increased by increasing water demand in the pipe's service area.
The water that is produced is held within the reservoir unit.The current reservoir located at WTP of Sekaran comprises two units and is constructed using steel tank technology.Each reservoir has a capacity of 100 m 3 .According to calculations based on SNI 7509: 2011, which outlines the procedures for technical planning of distribution networks and drinking water supply system service units, it may be concluded that the current reservoir fails to meet the necessary capacity.The determination of reservoir capacity uses the tabulation technique.The process of tabulated calculations involves the Based on the results, it is show that the reservoir capacity necessary to meet the current water usage or demand is calculated to be 207.4m 3 , with an average water usage of 20.38 L/s.According to the calculations, it is shown that the existing capacity of the reservoir does not meet the demand.Subsequently, the reservoir's capacity was computed for the year 2033, taking into account an average water demand of 47.64 L/s.In the year 2033, it is projected that a reservoir capacity of 284.91 m 3 will be necessary.
Current network modeling incorporates several assumptions, such as the age of pipes, the Hazen William factor, water leakage, and customer growth.This occurs as a result of insufficient data and time constraints.Certain data are also classified as confidential, such as the development plans outlined in SPAM's business plan.This leads to a decrease in the accuracy of the hydraulic modeling results.However, all of the aforementioned assumptions are derived from literature.Considering the research area is located in a rural area, it is possible to conduct measurements of demand patterns for hydraulic modeling during periods of high water usage, such as the Eid al-Fitr Homecoming, when there is a temporary increase in population that can impact water consumption habits.Therefore, the hydraulics modeling is also modified accordingly.

Conclusion
The results of a simulation of the extant distribution network using EPANET 2.2 indicate that the pressure at the most distant point does not meet the minimum pressure requirements of Minister of Public Works and Public Housing Regulation Number 27/PRT/M/2016.The Sekaran WTP's existing pumps can still meet the current water requirements, but they will be unable to provide water to customers in the next ten years should the number of customers rise.Recommendations for repairing the distribution network include parallelizing Pipe 20, Pipe 22, Pipe 26, Pipe 28, Pipe 42, Pipe 67, and Pipe 68 and installing a new 200 mm by 1960 m conduit connecting Ngarum Village and Jugo Village.Based on the results of the demand pattern measurement, it is necessary to modify the pump schedule, increase the operational duration of the pumps, and increase the number of operational pumps in order to meet the demand for water in 2033.According to the calculations, it is shown that the existing capacity of the reservoir does not meet the demand.In the year 2033, it is projected that a reservoir capacity of 284.91 m 3 will be necessary.Furthermore, to enhance the precision of the modeling outcomes, it is imperative to incorporate additional data, such as comprehensive information on age of pipes, Hazen William factor, and water leakage, in future investigations pertaining to hydraulic modeling.Considering the research area is located in a rural area, measurement of demand patterns and hydraulic simulations can be conducted by specifically focusing on days characterized by high water usage.

Figure 1 .
Figure 1.EPANET 2.2 Simulations Result of The Current Network at time 12 of 24 hours

Figure 2 .
Figure 2. Results of EPANET 2.2 Development Network Modeling in 2033 at time 12 of 24 hours

Table 1 .
Service Coverage of Sekaran WTP

Table 2 .
Domestic Water Demand in SPAM of Sekaran District

Table 3 .
Current Operational Schedule of the Sekaran WTP Pumps

Table 4 .
Demand PatternThe findings from the existing network simulation indicate that the system's performance is suboptimal, specifically when negative pressure is observed at the simulation time of 12:00.During that period, multiple intersections exhibited values that fell below the stipulations outlined in Minister of Public Works and Housing Regulation Number 27/PRT/M/2016, including in Kebalan Pelang Village, Kebalan Kulon Village, Kudikan Village, Jugo Village, Manyar Village, and Trosono Village as depicted in Figure1.

Table 5 .
Projected Water Demand on 2033

Table 6 .
Recommendations for Pipeline Network Modification

Table 7 .
Recommendation for 2033 Pump Operating Schedule creation of a table that records water usage and cumulative water usage, measured in cubic meters (m 3 ). 10