Service level indicators evaluation of water supply systems: water users’ perspective

ABSTRACT Service level of water supply systems (WSS) was assessed across in Ogun State, Southwest Nigeria. The WSS included: self-supply systems, communal water supply systems, and public water systems. Five service level indicators (access, quality, management, cost, and reliability) were assessed using structured questionnaires, targeting WSS users and owners in two categories: owners/resident users and non-resident users. Results show that owners/resident users restricted access of non-resident users to water assets, hence reducing adequate service level. Post-collection treatment was practiced by some users, using sodium hypochlorite solutions. Management and costs of WSS are borne by owners/resident users; costs borne by non-resident users is only from purchase of water. Reliability of WSS is hampered by geology and climatic seasonal variations as some WSS dried up during the off-rain season. Poor access to water has been identified as a major challenge facing non-resident users, amplified by limited coverage area of public water supply systems.


Introduction
Service level indicators (SLIs) have various definitions depending on the field of application.In general, SLIs are metrics that are used to determine the level of service customers receive from service providers.In the context of water resources management, several SLIs have been used to monitor water service levels to achieve water supply safety and sustainability (Lockwood and Gouais 2014;Deal and Sabatini 2020).Several water service level indicators (or measurable factors) have been developed to measure the service level of water supply systems and to determine the sustainability of those water supply sources (World-Bank 2017;Lockwood 2019;Deal and Sabatini 2020;Howard et al. 2020).This current study observed that there are, technically, no comprehensive SLIs for water supply systems, these measurement indices are quite extensive.However, examples of different SLIs indicate that access (sometimes captured as coverage, or equity or availability), quantity, quality and reliability are commonly used in literature (Howard 2002a;Carter 2006;Lockwood and Gouais 2014;Adank et al. 2016;Howard et al. 2020;Odjegba et al. 2020b).Service level indicators utilized by Carter (2006) were termed sustainability factors, comprising access, quality, reliability, cost and management.The five SLIs/sustainability factors were used in this study to assess the service delivery of water supply sources as metrics for evaluating the water supply sources.
Access is a key component of the SLIs.Access is defined relative to the volume of water consumed, classified as 'coverage' and linked directly to distance and maximum number of people that rely on a water supply system (Kayser et al. 2013;Dinka 2018).Also, Hutton and Chase (2017) associated the level of water access to health risk by highlighting that all hygiene needs can only be met when there is optimal access to water (100 litres per capita per day).Daily per capita water requirements vary globally when location, geology and climate change are taken into consideration (Cosgrove and Loucks 2015) and Gleick (1996) had recommended 50 litres per capita per day as a benchmark for basic water requirements.Ready access/availability of safe water is an integral requirement for wellbeing, food adequacy and socio-economic development (Sanneh 2018).
Quality is another vital component of SLIs.It is largely categorized based on compliance to WHO Drinking-water Quality Standard and/or the National Drinking-water Quality Standards of the countries where the water supply systems are domiciled (Moriarty et al. 2011;Kayser et al. 2013).The consequences of consuming poor quality water can be fatal.Understandably, quality is also captured in some studies and associated with sanitary risk (Oluwasanya 2013a;Adank et al. 2016;Odjegba et al. 2020a).For instance, Carter (2006) was specific in describing quality with contamination sources such as latrines and animal invasion of supplies.Contaminants that influence water quality cuts across household wastes, industrial wastes, agricultural wastes and pharmaceuticals and personal care products, to mention a few.The challenge is the broad spectrum nature of contaminants and the continued emergence of new ones that current water quality treatments struggle to deal with.
Reliability, quantity, and continuity are closely linked.Reliability, quantity, continuity and coverage are all influenced by the level of access to a water source, although, all four factors are slightly different depending on the definer.Deal and Sabatini (2020) defined reliability based on daily availability and functionality of water source, taking into consideration annual reliability of water source based on number of days per year.When a water source is reliable, consumers are guaranteed reasonable access in adequate quantity.WHO (2017) defines quantity and continuity separately.Continuity on the number of hours per day or per year that water is supplied, and quantity with respect to the volume per capita per day consumed.In all, reliability may be regarded as an umbrella under which quantity and continuity exist.
Cost and management are the least focused indicators.This may be due in part, to consumption-centred water supply studies based on majorly on access, quality and reliability.Cost (also known as affordability) is the defined relative to the quantity of water a household can afford without a strain on the household finance (Howard et al. 2020).However, affordability is premised on the ability and willingness to pay which may be applicable to public utilities or community owned water sources.Cost for privately owned water sources may cover construction and maintenance cost only.For consumers that cannot afford to own water sources and travel long distances, cost is even higher through the strain on health, purchase of water and loss of time and energy.Management is based on water supply source operations and maintenance.CWSA (2014) describes management in terms of provision of technical assistance and systems, while Lockwood and Gouais (2014) explain management with regard to water supply source performance in service delivery.
The objective of this current study was to access the state of water supply sources using SLIs from the water user's perspective to obtain information regarding access, quality, reliability, cost and management (SLIs) of the respective water sources from the water users directly.The SLIs assessment would provide insight into the impact of the respective water supply sources on the different categories of consumers and enable a comparison between source type and SLIs.The scope of the study extends beyond public water supply sources and includes self-supply (private owned hand-dug wells/boreholes) and communal water supply sources (mostly boreholes donated by organizations or individuals to communities).

Methodology
This study was carried out in six locations in Ogun State (Figure 1), Southwest Nigeria.The study locations: Abeokuta, Abigi, Imeko, Ijebu-Igbo, Sagamu and Sango-Ota were selected by stratified random sampling method based on population density (Table 1) and geographical spread.Ogun State has been plagued by scarcity of public water supply (Ogunyemi 2021), and residents rely on self-supply and communal water supply systems as alternative water sources.Water is abstracted by the State-owned public utility from both surface and ground water sources.
The surface water source is primarily the Ogun River (the largest body of water in the State).Public water supply systems across the State are, however, challenged by water shortages linked to break downs of infrastructure, power outages, poor coverage area, or complete absence of water supply in areas previously having water supply.Hence, consumers are compelled to alternate public water supply systems with self-supply systems and communal water supply systems such as handdug wells and boreholes as a coping strategy against inconsistent service.Although self-supply sources and communal sources are not without their own challenges.Sutton and Butterworth (2021) report that self-supply systems are high contamination risk prone, consumed untreated and unregulated, while communal water supply systems are conflict prone, poorly maintained, consumed untreated, unregulated and have limited access.
Types and classification of Water Supply Systems in the Study Area.The types and classification of water supply systems in the study area is presented in Figure 2. Three (3) categories of water supply systems were evaluated: public water systems, self-supply systems (hand-dug wells and boreholes) and communal water supply systems (boreholes only).Public water supply system (PWS) is a centralized water supply systems that provides potable water for the wider public and distributed through pipes or other conveyances and have, at least, fifteen service connections or regularly serves at least 25 individuals (USEPA 2015).The public utility in Ogun State is government owned and operated by the Ogun State Water Corporation (OGSWC).Self-supply systems (SSS) are privately owned water initiatives; excluded from government interventions or NGOs initiatives (Sutton and Butterworth 2021).Communal Water Supply System (CWSS) refers to heavily subsidized water supply services, which are implemented by governments and NGOs, but managed by communities (Danert and Sutton 2010) to which no individual can lay claim.
Users of water supply systems are in two categories: owners/resident users and non-resident users.Only PWS and SSS have owner/resident users and non-resident users categories.Ownership of CWSS cannot be claimed by an individual, hence, the absence of owners/resident users for CWSS.Owners/resident users of PWS are utility customers that own stand pipes (taps) within or outside their premises, while non-resident users are water users that abstract water from privately owned stand pipes.Owners/resident users of PWS do not just pay monthly or annual water bills, they are sometimes responsible for minor repairs.Owners/resident users of SSS are water users that have constructed handdug wells or boreholes within or outside their premises, while non-resident users are person who come to abstract water from the hand-dug wells or boreholes.Owners/resident users of SSS bear construction and maintenance costs, while non-resident users either abstracts water for free or pay a token.

Data collection
Two types of structured survey forms (questionnaires) were used to assess the service level indicators of the water supply systems (Appendix 1 and 2), namely, resident user/owners' and non-resident user questionnaires.Questions in both survey forms were adapted from Howard (2002a) and centered around the service level indicators.The goal of the study was to assess each service delivery indicator from two perspectives: owners/ resident users' views and the non-resident user.The sample size was determined using the method adapted from (Taherdoost 2017).The sample size was estimated using the population of the study locations using the equation from Taherdoost (2017).
Where n = required sample size P = percentage occurrence of a state or condition Z = percentage maximum error required E = value corresponding to level of confidence required Water supply systems were first selected using the zoning and cluster sampling approach (Howard 2002a).The respondents were then selected based on the water supply systems.So the sampled.Owners/resident users' questionnaires were administered to owners/residents of houses in which the water supply systems were domiciled.In the case of communal water supply systems, questionnaires were administered to residents living around the water supply system who also used such water supplies for their daily water needs.Non-resident user questionnaires were administered to persons making use of the water sources, but not residing close (that is persons residing farther than 500 m from the water source) to the water supply systems.A total of 441 questionnaires were administered in all the six study locations (Table 2), 186 questionnaires for owner/resident users and 255 non-resident user questionnaires.SSS = self-supply systems; CWSS = communal water supply systems; PWS = public water systems

Results and discussion
The data obtained from the owner/resident user and nonresident user survey is presented in Appendix 3 and 4 and in Figures 3 to 7, based on the relationship of each question with the service level indicators.The number of respondents is presented in percentages, represents the number of responders (in number unit of measurement) who commented on the service level indicators.

Access
Figure 3a Shows the owners/resident users and non-resident users response with respect to access.Owners/resident users control access to their water supply sources through restriction.Restricted access refers to exercise of control by owners/resident users over water supply sources to limit the access of nonresident users to water source.In Abeokuta, 21% of the owners/ resident users of self-supply systems/communal water supply systems and 80% of the owners/resident users of public water supply systems admitted to restricting access to their water supply systems.At Abigi, Ijebu-Igbo and Imeko, 15%, 19% and 21% of the owners/resident users of water systems apply restriction on non-resident users.However, more owners/resident users restricted access to their water supply sources at Abeokuta than the rest of the study locations.This may be connected to the fact that Abeokuta is prone to water scarcity as reported in previous studies (Orebiyi, Awomeso, and Adebayo 2008;Orebiyi et al. 2010;Shittu et al. 2010;Taiwo et al. 2011;Ayedun et al. 2015).For non-resident users, the impact of owner/resident's restriction of access to water supply systems included walking longer distances (Figure 3b) to obtain water and reduction in the volume of water available for use per day.
The level of access of non-resident users to water supply sources is contingent on proximity of the water systems to the residence of the non-resident user.Except for Sango-Ota, nonresident users in all other locations trekked distances farther than 10 meters to access water.All non-resident users in Sango-Ota accessed water supply systems less than 10 m walking distance.Seasonally water-stressed Abeokuta city recorded the highest (64%) percentage of non-resident users that had to walk more than 10 m to access a water supply system.Based on the classification of the level of access into no access, basic access, intermediate access and optimal access (Howard et al. 2020), the observed level of access non-resident users have in this study could best be classified as basic access.Howard et al. (2020) described basic access as accessibility to water within a 1000 m distance and 30 minutes round trip

Quality
Apart from 15% of owners/resident users of public water supply systems at Abeokuta (Figure 4a), all other owners/resident users in the study locations attested to the fact that the quality of their water is perceived as good.Similarly, Abeokuta, Sagamu and Sango-Ota recorded high non-resident users' responses that the quality of water they obtained is good (Figure 4b), while the least percentage of 13% for good water quality was recorded at Ijebu-Igbo.Oluwasanya (2009) reported that user perception of good water quality is premised, in part, on water clarity.That is, water clarity is an indication of good water: turbid water is poor water, clear water is good water.But clear (non-turbid) water may not be safe, even if it is perceived as such.Good and fair were adopted because they are believed to be easy to explain to respondents for measuring the respondent's perception of quality.It is interesting to note that from Figure 4a,b that owners/resident users reported their sources as being of good quality against the non-resident users' perception of fair quality.
On post-collection treatment method, Abeokuta (93%) and Sango-Ota (36%) recorded high levels of amongst the nonresident users with the use of Water Guard® as the most common water treatment method.Water Guard® is a sodium hypochlorite solution used in household water treatment.The practice of post-collection water treatment amongst users is good practice in areas where water is collected and stored, particularly, for the mitigation of water-related diseases due to water contamination during storage and transport activities.Still, more post-collection water treatment amongst nonresident water users should be encouraged.However, it should be noted that the practice may suggest that the quality of the available water may not be safe and may limit water use activities to non-ingestion purposes.

Reliability
Only Abigi, Sagamu and Sango-Ota recorded 100% reliability of the water supply systems (Figure 5a).Self-supply systems in Ijebu-Igbo and Imeko, and public water supply in Abeokuta are described as irregular by owners/resident users.Responders stated that the water supply systems dry up occasionally/seasonally. Public water systems are known to be irregular during the dry season, as surface water, which is a major source of raw water for public utilities, experiences considerable reduction in water volume resulting in the provision of intermittent supply (Orebiyi, Awomeso, and Adebayo 2008;Ufoegbune et al. 2010;Adekunle, Badejo, and Oyerinde 2013;Ayoade, Sikiru, and Okanlawon 2015).Owners/resident users attested to irregular self-supply/communal water supply systems in Abeokuta, Ijebu-Igbo and Imeko, which may be attributed to the geology of the three locations, which is classified as having a basement complex.Generally, basement complex rocks are characterized by low groundwater yield (Ifabiyi 2000;Akinwumiju and Olorunfemi 2016).Hand-dug wells and boreholes located in basement complex terrain are known to experience low yields, especially, during the dry season when supply cannot recharge the minimal porosity in the aquifer (Bayewu et al. 2017).
Non-resident users attributed reliability of a water supply source to the level of access to adequate water from the systems and by how regular or irregular the water supply sources are (Figure 5b).Non-resident users lamented limited access to water supply systems, which is mainly due to restrictions placed on the sources by owners/resident users such as locking of the water systems.The reliability of water systems as it relates to non-resident users was evaluated based on the quantity of water accessible for use.The quantity of water available was determined based on the basic daily water minimal requirement of 50 litres per capita per day (l/p/c/d) suggested by Howard et al. (2020).Sagamu recorded the highest percentage (100%) of non-resident users that had access to the basic 50 l/p/c/d, while the least percentage of 4% each was recorded for public water supply systems Abeokuta and selfsupply supply systems in Sango-Ota.

Cost
For cost, the maintenance/repair costs for most (94%) water supply sources in the study locations is borne by owners/ resident users (Figure 6a).However, non-resident users are sometimes charged for repairs, especially, in the case of CWS.Across the six study locations, owners/resident users are involved in selling of water from their water supply systems.Non-resident users' financial contributions Van Elsas et al. (2011) resulted from fees paid for water where owners/resident users were selling water (Figure 6b).Beyond this, nonresident users' financial contributions to water supply systems are minimal, or sometimes non-existent, across the study locations.Public water supply systems in Abeokuta, and SSS in Ijebu-Igbo, Sagamu and Sango-Ota recorded minimal (45%, 25%, 27% and 18% respectively) contributions of non-resident users to water supply systems management.However, non-resident users' contributions are non-existent in self-supply supply/communal water supply systems at Abeokuta, Abigi and Imeko.Public water supply systems in Abeokuta and self-supply supply systems in Sagamu recorded the highest percentage of water supply systems support for maintenance and repair with the associated high prevalence of water purchasing.

Management
Management was categorized based on maintenance.Maintenance in this context was defined to responders as supervision, repair responsibilities, protection and cleaning.Supervision involved overseeing the operation/use of the water source by users and protection involves upkeep of the water source by looking out for broken parts, highlighting where the system required fixing and ensuring that the structure of the water source remains intact.Repair responsibilities refers to bearing repair costs.Cleaning is ensuring the water source is well kept, especially, ensuring it is free from potential sources of contamination. Figure 7a shows that repair responsibility by owners/resident  users.Eighty-seven percent (87%) of SSS/CWS and 93% of PWS in Abeokuta of owners bear the responsibility of repairs of their water supply sources, while repair responsibility is bore 100% of SSS by owners in all.Only 13% (SSS/CWS) and 7% (PWS) have their repair borne by resident users.Non-resident users' contributions to management were describe contribution or no contribution (Figure 7b).The contributions were described in terms of contribution to repairs or cleaning.Non-resident users had zero contributions to management in Abeokuta(SSS/CWS), Abigi(SSS) and Imeko(SSS).Non-resident users contributed to management through cleaning of the PWS in Abeokuta (45%), SSS in Ijebu-Igbo (25%), Sagamu (27%) and Sango-Ota (18%).

Assessment of service level indicators: implications for sustainable water management
The results presented in this paper highlighted a few concerns on the evaluated indicators.For instance, the claim by most of the responders that the quality of their water was perceived as good may not be a guarantee of high-quality or safe water.Similarly, the practice of post-collection water treatment method by some users suggested that water from the available water supply systems in the study area may not always be perceived as safe.Oluwasanya (2009) highlighted the need to understand why water users may not see anything that is wrong with their water quality.It was reported that there are certain user-prescribed criteria for good water and preconceived water safety conditions (Oluwasanya 2009).Preset criteria for good water include 1) water clarity -turbid water is poor quality, Clear (un-turbid) water is of good quality, 2) number of users of particular system (if the number of users of a particular system is large, then the water must be good), and 3) the length of time the water source had been in use without users being infected with water-related illness (Oluwasanya 2009).That is, once the preset criteria are in place, then the water must be good.However, clear water though appearing good does not mean safe water.Long-term usage without infection with water disease may mean localized community immunity.Immunity to water disease due to longterm usage does not imply the water is safe for use for new users and would be risky to non-residents who are tapping this supply infrequently.Usage of source water by many people also does not imply the water is safe for use and is related to acquired immunity.Thus, as suggested by Oluwasanya (2009), preset water user criteria for good water, in part, must be aligned with established water safety guidelines.Water users who do not see anything wrong with their water may find it difficult to see the need to take informed water safety measures or adopt appropriate management procedures.There is therefore, the need to always identify correctly through research (e.g.service level indicator assessment) the attitude of water users to water safety and development indicators, and the factors, which inform the attitude, so as to target guidance, enlightenment and training appropriately.
Also, the limited coverage area and unreliability of Public Water Systems is noted in this paper.This has led to increased adoption of self-supply systems and communal water supplies as coping strategies (Oluwasanya, Smith, and Carter 2011a;Sutton and Butterworth 2021).The use of alternative water supplies as coping strategy ensures water supply consistency.However, the resulting reliance on alternative water sources further exposes consumers to the risks of water-related ailments -which could sometimes be fatal.In addition, buying water from sources other than PWS can strain the financial budgets of water users.The need for the provision of adequate, safe and affordable drinking-water through functioning public utilities and to drive Sustainable Development Goal (SDG) 6, cannot be overemphasized.SDG 6 seeks to ensure availability and sustainable management of water and sanitation for all by the year 2030.However, provision of PWS is capital intensive and rests on the government.The rate of increase in population and city expansion in the study areas had far exceeded the coverage area of existing facilities of the public water supply systems.While fixing the highlighted problem is long term, the short-term goals to protect public health may be to 1) create ongoing awareness on the importance of consuming safe drinking-water, 2) emphasize and encourage affordable postcollection water treatment methods and 3) appropriate system management.A good strategy to achieve the first and second short-term goals could be to educate consumers on the cost- benefit analyses of living a water-related disease free, especially, when considering the fatality of such diseases, which can involve considerable costs in labor and health care.But adherence to the stated practices maybe a different ball game, as water costs of post-collection treatment, cleanliness of water hauling and storage vessels and a lack of control over water quality when forced to buy water from owner/residential self-supply systems can expose non-residents to enhanced disease risks.Nonetheless, appropriate system management may be driven through continued advocacy to domesticate Water Safety Planning for the identified three main water supply sources in Nigeria towards the provision of safe and affordable water for all, without leaving anyone behind.

Conclusion
This paper evaluated five service level indicators of water supply systems in selected locations in Ogun State, Southwest Nigeria.All self-supply supply/communal water supply systems in the study area are privately owned or constructed by nongovernmental organizations.As such, the government is not involved in the construction, operation, maintenance and management of the water sources.Poor access to water supply systems by non-resident users is evident and quite prevalent.Non-resident users walk more than 10 m to access water.Poor access is further compounded by limited coverage of public water supply systems and seasonality for other sources, such as self-supply or communal hand-dug wells.Water users rely on self-supply and communal systems as alternative sources during dry seasons and other times when the public water system is not available.As such, self-supply and communal sources should be included in evaluation and assessment of sustainable water supplies.Restriction of access to water supply systems by owners/resident users affects the volume of water that nonresidents users can get, resulting in walking long distances to obtain water and restriction of hygiene practices known to reduce water-related disease burdens.
While some water users do not subject their water to postcollection treatment, large numbers of non-resident users practice post-collection water treatment in Abeokuta and Sango-Ota.Abeokuta and Sango-Ota are urban cities and are, generally, expected to have residents with higher levels of literacy compared to other study locations.However, post-collection water treatment practices should be encouraged for all users who haul and store water.Costs to cover water supply systems maintenance/repair on the part of owners/resident users, and for the purchase of water on the part of non-resident users, are factors that can impact the accessibility of water supplies and public health.Coverage area and the volume of public water supply systems needs to be increased to reduce reliance of water users on questionable alternative sources that can expose water users to water-related diseases or limit water usage.It is important to always correctly identify the water user perceptions of their water supplies through research or assessment of development indicators.Such evaluation would target guidance and identify appropriate training and investments that need to be made to assure the provision of adequate amounts of safe drinking water to supply more than basic needs and support appropriate hygiene uses.Water supply is a complex topic, and as always, people will seek to find the optimum solutions for their particular circumstances and needs.

Highlights
• Service Level Indicators (SLIs) are metrics that are used to determine the level of service customers receive from service providers.
• In the context of water resources management, SLIs have been used to monitor water service levels to achieve water supply safety and sustainability.
• Several water service level indicators (or measurable factors) have been developed to measure the service level of water supply systems and for determining the sustainability of those water supply sources.
• Service level indicators (termed sustainability factors) comprising access, quality, reliability, cost and management.
• The five SLIs/sustainability factors were used in this study to assess the service delivery of water supply sources as metrics for evaluating the water supply sources.

Figure 1 .
Figure 1.Map of Ogun State in Nigeria showing the study locations (Reproduced using Arc Map 10.1).

Figure 4 .
Figure 4. Owners/resident user and non-resident users' perception of water quality of water supply systems.

Figure 5 .
Figure 5. Respondents' perception of reliability of water supply systems.

Figure 6 .
Figure 6.Respondents' contribution to water supply systems oin relation to cost.

Figure 7 .
Figure 7. Respondents' participation in water supply systems management.

Table 1 .
Population density of the study locations.
Figure 2. Types and classification of water supply systems in the study area.

Table 2 .
Distribution of questionnaire in six locations in Ogun State, Nigeria.
Figure 3. Owners/resident user and non-resident users description of access to water supply systems.