Chapter Fourteen: Drinking Water and Wastewater Quality Monitoring, Surveillance and Compliance

1 Chapter Fourteen: Drinking Water and Wastewater Quality Monitoring, Surveillance and Compliance

Drinking water quality monitoring and surveillance of a water supply schemes entails the continuous monitoring of public health along with vigilant assessment and control of safe potable water supply. The Ministry of Water has developed a National Guidelines on Drinking Water Quality Monitoring and Reporting of 2018 which will be reviewed from time to time. The guideline which may be downloaded from the Ministerial website (https://www.maji.go.tz/pages/guidelines) provides systematic steps to be considered during undertaking of water quality monitoring from the catchment/source throughout the water supply system up to the consumer. Also, the quality of portable water has to meet the latest edition of TBS Standards.

1.1 Importance of Good Water Quality

Safe potable water is the first step to promote good health of the community. Experience has shown that community health and water quality are directly related to each other and an improvement of drinking water quality is followed by an improvement in the community’s health. Human activities; rapid industrialization and agrochemical contamination increasingly affect the quality of water resources. Moreover, infant mortality, mostly from diarrheal and other water borne and water related diseases are of great concern. In spite of the significant achievements in improvement of water supply and sanitation services, many factors render good quality water unsafe by the time it reaches the consumers. Poor operation management and unsatisfactory sanitary practices are the major key areas responsible for water contamination. Water quality management and surveillance practices ensure safe water supply to the consumers.

1.2 Definitions

While describing water quality, certain terms are frequently used, which are to be clearly understood and correctly used. Some of the definitions are given below:

(a) Pollution - is the introduction into water of substances in sufficient quantity to affect the original quality of water, make it objectionable to sight, taste, smell or make it less useful,

(b) Contamination- is the introduction into water of toxic materials, bacteria or other deleterious agents that make the water hazardous and therefore unfit for human use (degradation of water quality),

(c) Potable Water - that is satisfactory for drinking purposes from the standpoint of its chemical, physical and biological characteristics. Palatable Water that is appealing to the sense of taste, sight and smell. Palatable water need not always be potable,

(d) Parts per million (ppm) or milligrams per litre (mg/l) - these terms are used to express the concentrations of dissolved or suspended matter in water. The parts per million (ppm) is a weight to weight or volume to volume relationship. Except in highly mineralized water, this quantity would be same as milligram per litre. This is preferable, since it indicates how it is determined in the laboratory,

(e) pH of water - is an expression of the Hydrogen ion concentration. Alkaline water has with pH of above 7 and acidic water has pH of below 7 whereas water with pH 7 is neutral. Physiological effect - having effect on the normal functions of the body. Pathogens disease - producing organisms,
(f) Bacteria - a group of universally distributed, essentially unicellular micro-organisms lacking chlorophyll,
(g) Virus - the smallest form capable of producing infection and diseases in human beings,
(h) Coliform Bacteria - group of bacteria predominantly inhabiting the intestine of human beings and animals, but also occasionally found elsewhere. Used to indicate presence of faecal-pollution,

(i) Enteric - having its normal habitat in the intestinal tract of human beings or animals,

(j) Chlorine Residual - chlorine remaining in the water at the end of a specified period that is not combined with other chemicals and is available to disinfect any additional contaminants introduced to the water,

(k) Chlorine Demand - the difference between the amounts of chlorine added to water and amount of residual chlorine remaining in the water at the end of a specified period.

1.3 Water Supply and Surveillance Agencies

A water utility is responsible for maintaining the safety of water supplied to the community from the source to the point of consumption. The main objectives of water quality monitoring are:
(a) To determine the quality of water in its natural state in view of its present and future needs,
(b) To assess the suitability of water for the required use,
(c) To find out the pathways for pollution, if any.

Operational and Regulatory Monitoring of water quality involves field and laboratory testing of water samples collected from various points in the water supply system, including the source, water purification plants, service reservoirs distribution systems and consumer end. Continuous water quality monitoring involves good operating practices and preventive maintenance, as well as the regular routine testing and monitoring of water quality to ensure compliance with standards.

Surveillance is an investigative activity undertaken by a separate agency, to identify and evaluate factors posing a health risk to drinking water. Surveillance requires a systematic programme of surveys that combine water analysis and sanitary inspection of institutional and community aspects, and reporting system. Sanitary inspection of water supply system should cover the whole system including water sources, rising mains, treatment plants, storage reservoirs, and distribution systems; to identify the most common risks and shortcomings in the water supply. Moreover, surveillance is concerned with all sources of water used for domestic purpose by the population, whether supplied by a water supply utility/agency or collected from other individual sources. So it is important to inspect and analyse all sources of water used and intended to be used for human consumption. Surveillance agency should communicate to the water supply utility/agency and pinpoint the risk areas and give advice for remedial action. It should also maintain good communication and co-operation with water supply utility/agency for detection of risk areas and remedial action for betterment of the water supply.

1.3.1 Planning and Implementation

Systematic planning, keeping in view the fundamental objectives, is necessary for successful implementation of drinking water quality control programme.

1.3.2 General Consideration and Strategies

Quality control activities should be initiated as per the norms of national and international guidelines for laboratory analysis. Surveillance agency should carry out periodic surveillance of all aspects of water quality safety including sanitary inspection and spot checks and result should be reported to the concerned water supply organization to implement remedial action when and where necessary.

Water supply surveillance can be planned in a progressive manner considering the availability of resources. It should start with a basic programme, which could generate useful data to plan advanced surveillance as resources, and conditions permit. The initial pilot scale programme should cover minimum basic strategies including fewer water quality parameters that provide a reasonable degree of public health protection and should be widely applicable. Careful planning of training and resource provision is very essential right from the beginning.

1.3.3 Surveillance Programme

Principally, surveillance activities are similar but the actual extent may differ between urban and rural communities; and according to the types of water supply. They should be adapted to local conditions; availability of local finances, infrastructure and knowledge. Water supply provider and surveillance agencies, depending on resources available with them, will develop the programme for monitoring and surveillance of drinking water quality. Following factors should be taken into consideration while implementing of surveillance activities:
(a) The type and size of the water supply systems,
(b) The existing and available equipment,
(c) Local employment practices and the level of training,
(d) Opportunities for community participation,
(e) Accessibility of systems keeping in view of geographical and climatic conditions,
(f) Communication and transport facilities available.

1.3.4 Information Management

The flow of information between and within the water supply and surveillance agencies is necessary to maximize the quality of service to the consumer and protection of public health. The report provided by the surveillance agency to water supply providers may include but not be limited to:
(a) The summary reports of condition of water supply and water quality analysis,
(b) Highlight those aspects, which are considered inadequate to sustain the safety of water and needs urgent action,
(c) Recommendation of remedial action in case of emergency.

1.3.5 Community Based Monitoring and Surveillance

Community participation is an essential component of the monitoring and surveillance framework. As the primary beneficiaries, community can play an important role in surveillance activity. They are the people who may first notice the problems in water supply system and report it to the concerned water supply utility/agency or take remedial action if possible. Establishing a genuine partnership with the community creates a climate of trust and understanding, which generates interest and enthusiasm. It also provides a good foundation for other educational activities such as promotion of good hygiene practices.

Health department or water supply utility/agency should help in providing necessary training while community water committee or health committee can supervise the work. The community participation includes:

(a) Assisting field workers in water sample collection, including sample location points, existing damaged networks, causing/likely to cause contamination of drinking water,
(b) Assisting in data collection,
(c) Monitoring water quantity, quality, and reporting findings to surveillance staff regularly,
(d) Ensuring proper use of water supply,
(e) Setting priorities for sanitation and hygiene and educate community members,
(f) Undertake simple maintenance and repair work. Refer problems which require special attention to the water utility,
(g) Disseminate results and explain the implications with respect to health with the objective to stimulate involvement in actions to keep water clean, safe and wholesome.

1.3.6 Surveillance Action

Surveillance action comprises of: (a) Investigative action to identify and evaluate all possible factors associated with drinking water, which could pose a risk to human health, (b) Ensure preventive action to be taken to prevent public health problem, (c) Data analysis and evaluation of the surveys, (d) Reporting to the concerned authorities the outcome.

1.3.7 Sanitary Survey

Sanitary survey is a periodic audit of all aspects of all the water supply system. Systematic programme of sanitary surveys includes sanitary inspection, water quality analysis, and evaluation of data and reporting.

Sanitary Inspection Report The sanitary inspection report shall cover the following:

(d) Identify potential sources and points of contamination of the water supply,

(e) Quantify the hazards attributed to the source and supply,

(f) Provide a clear, graphical means of explaining the hazards to the operator/user,

(g) Provide clear recommendations for taking remedial actions, to protect and improve the supply,

(h) Provide basic data for use in systematic, strategic planning for improvement

Moreover, inspection reports should not be restricted to water quality but should take in to account other service condition such as coverage, cost, condition and quantity.

Such surveys are important from the point of view of operation and maintenance.

1.4 Wastewater Quality Monitoring

Systematic planning as well as keeping in view the fundamental objectives is necessary for successful implementation of wastewater effluent discharges quality control programme.

1.4.1 General Consideration and Strategies

Quality control activities should be initiated as per the norms of national standards and international guidelines for laboratory analysis. Surveillance agency should carry out periodic surveillance of all aspects of wastewater effluent quality discharges including sanitary inspection and spot checks and results should be reported to the concerned utility as well as the regulator to implement remedial action when and where necessary.

Wastewater effluent surveillance can be planned in a progressive manner considering the availability of resources. It should start with a basic programme, which could generate useful data to plan advanced surveillance as resources, and conditions permit. The wastewater effluent quality discharges should comply with the latest edition of Tanzania Standards, TZS 860, Limits for Municipal and Industrial Wastewaters. The standards prescribe the permissible limits for municipal and industrial effluents discharged directly into water bodies (i.e. receiving water bodies) (EWURA, 2014).

The initial pilot surveillance scale programme should cover minimum basic strategies including fewer wastewater effluent quality parameters that provide a reasonable degree of public health protection and should be widely applicable. Careful planning of training and resource provision is very essential right from the beginning.

1.4.2 Monitoring Programme

Principally, monitoring activities should be adapted to local conditions; availability of local finances, infrastructure and knowledge. WSSA/Agency responsible for wastewater/sanitation management and Surveillance agencies (e.g. EWURA or RUWASA), depending on resources available with them, will develop the programme for monitoring and surveillance of wastewater effluent discharges quality. The following factors should be taken into consideration while implementing of wastewater quality surveillance activities:

(a) The type and size of the wastewater /sanitation systems,

(b) The existing and available equipment,

(c) Local employment practices and the level of training,

(d) Opportunities for community participation,

(e) Accessibility of systems keeping in view the geographical and climatic conditions,

(f) Communication and transport facilities availability.

1.4.2.1 Wastewater Quality Monitoring Parameters

The selection of parameters that constitute the wastewater quality monitoring programme is to be made on the basis of the latest edition of Tanzania Bureau of Standards: TZS 860. The parameters proposed for regular check monitoring by the Water Supply and Sanitation Authorities (WSSAs)/RUWASA/other agencies should be those required by the latest edition of EWURA water and wastewater quality monitoring guidelines:

(a) Ammonium,

(b) Biological Oxygen Demand (BOD),

(c) Chemical Oxygen Demand (COD),

(d) Colour,

(e) Faecal Coliforms,

(f) Nitrate,

(g) pH,

(h) Phosphorus,

(i) Total Coliforms,

(j) Total Suspended Solids (TSS).

The above list of parameters subjected to regular monitoring could be expanded (to include some metals) to take into account the nature of the quality of wastewater collected from industrial, commercial or residential establishments by the sewerage network or brought to the wastewater treatment plants by vacuum trucks. Chemical parameters should be added to the list for monitoring in consultation with Energy and Water Utilities Regulatory Authority (EWURA) or RUWASA or Basin Water Boards and the National Environment Management Council (NEMC).

1.4.2.2 Audit Monitoring

The Audit Monitoring is to provide information necessary to determine whether or not all the parametric values specified in the latest edition of TZS 860. Limits for Municipal and Industrial Wastewaters are being complied with.

The selection of parameters that constitute the Audit Monitoring is to be made on the basis of the latest edition of TBS Standards TZS 860. All such parameters must be subjected to audit monitoring, unless it can be established that the nature of the wastewater coming from the sewered area are not expected to contain some of the parameters to be excluded.

EWURA or RUWASA or any outsourced Agency will carry out monitoring as an external auditor and WSSAs/UWSSAs will conduct monitoring as an internal auditor.

1.4.2.3 Sampling Locations and Sampling Frequency

Since the effluent standards apply to Municipal, WSSAs, Utility and Industrial effluents discharged directly into water bodies, it implies that sampling locations should be points at which the effluent leaves the wastewater treatment plants just before it enters the receiving water bodies. Sampling locations and sampling frequency should be those required by the latest edition of EWURA water and wastewater quality monitoring guidelines.

1.4.3 Information Management

The flow of information between and within the WSSA/Agency responsible for sanitation management and surveillance agencies (i.e. EWURA or RUWASA & NEMC) is necessary to maximize the quality of service to the consumer and protection of public health. The report provided by the surveillance agency to wastewater management may include but not be limited to:

(a) The summary reports of condition of wastewater and effluent or faecal sludge quality analysis,

(b) Highlight those aspects, which are considered inadequate to sustain the quality of wastewater/sludge and needs urgent action,

(c) Recommendation of remedial action in case of emergency.

1.4.4 Community Based Wastewater Quality Monitoring and Surveillance

Community participation is an essential component of the Wastewater quality monitoring and surveillance framework. As the primary beneficiaries, community can play an important role in wastewater surveillance activity. They are the people who may first notice the problems in wastewater / sanitation projects and report it to the concerned WSSA/Utility/agency or take remedial action if possible. Establishing a genuine partnership with the community creates a climate of trust and understanding, which generates interest and enthusiasm. It also provides a good foundation for other community educational activities such as promotion of good hygiene practices.

The health department or WSSA/Utility responsible for wastewater/ sanitation should help in providing necessary training while CBWSO or the community health committee can supervise the work. The community participation includes:

(a) Assisting field workers in effluent/discharges sample collection, including sample location points, existing damaged sewers or treatment plants, causing/likely to cause contamination of the environment,

(b) Assisting in data collection,

(c) Monitoring wastewater effluent/discharges quantity, quality, and reporting findings to surveillance staff regularly,

(d) Ensuring proper disposal of effluent /discharges and sludge,

(e) Setting priorities for sanitation and hygiene and educate community members,

(f) Undertake simple maintenance and repair work. Refer problems which require special attention to the WSSA/Utility or regulatory agency,

(g) Disseminate results and explain the implications with respect to health with the objective to stimulate involvement in actions to keep environment clean, safe and wholesome.

1.4.5 Wastewater Quality Monitoring Surveillance Action

Surveillance action comprises of:
(a) Investigative action to identify and evaluate all possible factors associated with wastewater effluent discharges and sludge disposal, which could pose a risk to human health and environment in general,
(b) Ensure preventive action to be taken to prevent public health problem,
(c) Data analysis and evaluation of the surveys,
(d) Reporting to the concerned authorities or the regulator the outcome.

1.4.6 Wastewater Effluent Quality Survey

Wastewater effluent quality survey is a periodic audit of all aspects of all the wastewater and sanitation systems. Systematic programme of surveys includes sanitary inspection, wastewater effluent discharges and faecal sludge quality analysis, and evaluation of data and reporting.

1.4.7 Wastewater Quality Inspection Report

The wastewater quality inspection report should cover the following:
(a) Identify potential sources and points of contamination due to wastewater effluent discharges and sludge,
(b) Quantify the hazards attributed to the ground water sources, water supply network, and storm water,
(c) Provide a clear, graphical means of explaining the hazards to the operator/user,
(d) Provide clear recommendations for taking remedial actions, to protect and improve the effluent discharges and sludge handling /disposal,
(e) Provide basic data for use in systematic, strategic planning for improvement. Moreover, inspection reports should not be restricted to wastewater effluent/ discharges quality but should take into account other service condition such as coverage, cost, condition and quantity. The wastewater quality surveys are important from the point of view of operation and maintenance.

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