Water Supply and Health PDF

PH 136: ENVIRONMENTAL AND OCCUPATIONAL HEALTH WATER SUPPLY AND HEALTH Prof. Marian Fe Theresa C. Lomboy-Capino | January 30, 2025 ​ Issues concerning water supply have become more...

PH 136: ENVIRONMENTAL AND OCCUPATIONAL HEALTH WATER SUPPLY AND HEALTH Prof. Marian Fe Theresa C. Lomboy-Capino | January 30, 2025 ​ Issues concerning water supply have become more OUTLINE frequent in the recent years A.​ Introduction ○​ Also attributed to typhoons and extreme weather a.​ SDG 6: Clean Water and Sanitation events B.​ Water Supply in the Philippines ​ PhilStar Article: “Don't let taps run dry, senators say as a.​ Local Situation i.​ Threats to Water Supply Maynilad penalized for service interruptions” b.​ Levels of Water Supply in the Philippines ○​ Discussed how water service interruptions became i.​ Level 1: Point-Source frequent in Metro Manila a few years ago. ii.​ Level 2: Communal Faucet System ○​ This led to the senate increasing pressure on water iii.​ Level 3: Individual Household Connection service providers to ensure adequacy and accessibility iv.​ Benefits of Discussing the Three Levels of of water supply throughout 2022 Water Supply ​ PhilStar Article: “Over 100 Cases of Diarrhea, C.​ Relevant Policies and Regulations a.​ Code on Sanitation of the Philippines (P.D. 856) Gastroenteritis in Odette-hit areas” b.​ National Policy on Water Safety Plan for all Drinking ○​ Shows how vulnerable our water supply system is in Water Service Providers (A.O. 2014-0027) times of extreme weather events i.​ Water Safety Plan ○​ “Pag nagkakaroon ng bagyo at nadisplace ang mga c.​ Philippine National Standards for Drinking Water tao, sumusunod na diyan ang mga outbreaks ng (PNSDW) water-borne diseases, or other related seasonal i.​ Classifications for Drinking Water Quality Parameters diseases like leptospirosis.” ii.​ Microbiological Standards and Characteristics ​ Challenges will persist if we fail to recognize that our water D.​ Influence of Water Supply to Health resources are finite. Ongoing water pollution will continue a.​ Water-Related Diseases to threaten these resources. i.​ Water-Borne Diseases ii.​ Water-Washed Diseases SDG 6: CLEAN WATER AND SANITATION iii.​ Water-Based Diseases iv.​ Water-Vectored Diseases ​ Ensure universal access to clean water and sanitation E.​ Public Health Intervention Programs for Safe ​ 6 targets to be achieved by 2030: Drinking Water Table 1. SDG 6 Target Descriptions. a.​ Philippine Clean Water Act (R.A. 9275) No. Specific SDG 6 Target b.​ Sagana at Ligtas na Tubig sa Lahat (SALINTUBIG) Program 6.1 All have access to safe and affordable drinking water c.​ Safe Water All have access to adequate sanitation and hygiene. d.​ iWASH Program 6.2 Open defecation is eliminated → entails the provision F.​ References of latrine facilities Improve water quality by reducing pollution, INTRODUCTION 6.3 minimizing release of hazardous chemicals, and From BSPH 2025 Trans: halving the population of untreated wastewater ​ Clean water is a basic human need. Thus, it should be Increase water use efficiency across all sectors and readily accessible to anyone. ensure sustainable supply of water to reduce the ​ However, many countries are confronted with problems number of people suffering from water scarcity → 6.4 related to water supply due to: water has to be available throughout the year and →​Inadequacies and lack of investment in water supply no one is left behind infrastructure (i.e. no individual household connections) Fully implement integrated water resource →​Lack of planning - some communities are still 6.5 management which looks at water resources considered water-less holistically. ​ As a consequence, millions of people, especially children, still die from water-related illnesses Protect and restore water-related ecosystems 6.6 including mountains, forests, wetlands, rivers, aquifers, ​ Focused on: “drinking water supply and public health” and lakes ○​ There will be a separate discussion for wastewater ​ Emphasis: Providing safe water to communities can only treatment and disposal be achieved through a holistic and integrated ​ With the challenges in maintaining the systems of drinking approach. This is the reason why the SDG targets water supply, we also face corresponding health integrated water resource management and the implications when things go wrong. protection of ecosystems from pollution. WATER SUPPLY IN THE PHILIPPINES LOCAL SITUATION ​ Majority have access to safe water (treated water: water that can be consumed at the household level): ○​ National: 10,817,911 (78%) out of 13,923,267 households ○​ NCR: 1,403,245 (71.4%) out of 1,964,408 households ○​ However, with respect to SDG target 6.1, around 20% of households still do not have access to clean water Figure 1. News articles on water supply issues. (See links: 1,2,3,4). #MagkabigkisBenteSais Team 03 | 1 of 10  supply → Still far from achieving goal, thus efforts ​ “Supposedly, yung tubig na nanggaling sa piped water must be strengthened system is already safe for drinking” ​ Some households that lack access to safely managed ○​ Undergoes filtration to remove particulates, water sources collect water from high-risk water sources. sediments, biological and chemical agents + ○​ High-risk water sources = likely contaminated disinfection using chlorine before distribution ​ Unprotected from surface runoff (no covering) ○​ Observerved in other countries → Efficiency and ​ Collected using potentially unclean containers quality of tap water treatment may vary from one ​ May carry pathogenic microorganisms place to another (other regions have more ○​ Example: Wells advanced technologies, regular monitoring, less ​ Considered high-risk due to proximity to toilets, affected by flood, etc.) pig pens, and stagnant water. ​ Generally, still a continuing challenge in the Philippines ​ Shallow wells are linked with outbreaks of water-borne illnesses ​ Recommended to have at least 25-meter distance THREATS TO WATER SUPPLY (BSPH 2025) but cannot be avoided due to clustering of 1. Rapid Population Growth houses (see PD 856) (BSPH 2025 Trans). ​ Increase in population leads to an increase in demand of water, while supply remains finite ​ Increase in demand further leads to over-extraction of groundwater ○​ Decline in groundwater level ○​ Saltwater intrusion in coastal areas ○​ Drying up and contamination of wells ​ Once groundwater supply is contaminated, it is very difficult to improve and restore quality due to the long residence time of around 2 weeks to thousands of years ○​ Long residence time: how long groundwater stays in rivers 2. Rapid Urban Development ​ Disrupts the water cycle by decreasing aquifer recharge or preventing infiltration of water back into the ground ​ Developments in urban areas led to establishment of different structures that prevent natural movement of Figure 2. High-risk water sources. water into the ground ​ Outbreaks can also occur with “supposedly safe” ○​ Leads to increased peak flows and runoff → flooding piped water systems. ○​ e.g. Typhoon Ondoy in NCR ○​ They can be contaminated by biological, chemical, 3. Domestic, Industrial, & Agricultural Wastes and even radiological agents because of: ​ These wastes can contaminate the surface water and ​ Illegal connections - Pipes have breaks, rendering groundwater supply by leaching the water system vulnerable to contamination ​ According to DOH: 50% of groundwater sampled tested ​ Contamination from anthropogenic and natural positive for E.coli or fecal coliforms sources ○​ Water-related diseases remain one of the leading ​ Improper or inadequate water treatment - must be causes of morbidity in the country chlorinated to kill microorganisms Table 2. Outbreaks of water-borne diseases attributed to piped water systems in 4. Watershed Degradation the Philippines. ​ Watersheds are valuable sources of water supply, Disease # of degradation of it is caused by deforestation Date/Loc Water Source Outbreak cases ​ Deforestation causes soil erosion and siltation of water Jan 21, 2007 bodies Typhoid fever 408 Loon Waterworks Bohol ○​ Denudation of forests and watersheds results to Jul 5, 2007 Private water flash floods in mountainous areas Shigella flexneri 400 Cavite providers ○​ e.g. Typhoon Sendong (2011) flash floods wiped out Jul 9, 2007 Typhoid fever 284 Developed spring communities in Cagayan de Oro Davao del Sur Apr 2008 ​ It is important to maintain vegetation in watersheds to Typhoid fever 1200+ Water district provide surface roughness, promoting water infiltration to Laguna Jul 2009 Private water the ground and preventing flash floods in low-lying areas Cholera Cavite providers LEVELS OF WATER SUPPLY IN THE PHILIPPINES QUESTION: Is it safe to drink tap water (from faucet)? LEVEL 1: POINT-SOURCE ​ While there are many who rely on tap water as a ​ Includes protected wells or developed springs with an drinking water source, there are also many who do not, outlet but WITHOUT a pipe distribution system due to the perception of it not being completely safe. ○​ You have to go to the water collection site to gather ​ Though some households have filtration systems (ex. water reverse osmosis-installed system) for their tap water, ○​ “Protected” = reservoir is encased, covered, and previous outbreaks in piped systems raise concerns on unaffected by run-off the need for further treatment or disinfection to ensure ​ This source is typically found in rural areas where homes that there are no pathogens left. are dispersed too thinly to justify a piped distribution system PH 136 | Water Supply and Health 2 of 10  ○​ Example: Shallow well shown earlier in Fig 2. ○​ Especially true during dry seasons since the water is ​ To ensure optimal coverage and sufficient and reliable regulated so that it is sufficient to last throughout the water supply for community members: year. ○​ Farthest household should not be >250 meters away ○​ Insufficiency of the water supply leads to water from the source service interruptions. ○​ There should be 1 point source for every 15 households ​ A practice for this level is chlorination of the reservoir so that it is safe to use and consume Figure 5. Individual Household Connection Water Supply Source BENEFITS OF DISCUSSING LEVELS OF WATER SUPPLY Figure 3. Point-Source Water Supply Source Community Planning and Development ​ Understanding the levels of water supply helps us in LEVEL 2: COMMUNAL FAUCET SYSTEM designing water supply systems that are appropriately ​ A system composed of a source, a reservoir, a piped scaled for different types of communities distribution network, and communal faucets ○​ If there are very few households in the community, it is ○​ The defining characteristic of a level 2 water supply acceptable to have a level 1 water supply source source is the communal (shared) faucets. ○​ Example: For an urban and densely populated area, a ​ Ideal for rural areas where houses are clustered or Level 3 water supply source would be appropriate located more closely together. ​ To ensure access, the farthest house should not be >25 Infrastructure Improvement meters away and there should be 1 faucet for every 4 to 6 ​ When we evaluate the current water supply levels in the households. communities, it can help us identify gaps and areas ​ People still need to go to the communal faucet, but there is needing improvement a pipe distribution system—allowing communal faucets to ○​ This can guide us in upgrading our water supply be placed in several locations within the community. infrastructure such as transitioning from lower to ​ Water also undergoes treatment in the reservoir before higher levels being distributed through the pipe distribution system. ○​ Example: communal faucets for one community may no longer be adequate as its population increases Emergency Response ​ In times of natural disasters, understanding the levels of water supply can aid in planning and implementing emergency response strategies ○​ Example: Level 1 systems may require specific maintenance or support to ensure that they function properly during emergencies ​ There is a possibility that reservoir may have Figure 4. Communal Faucet Water Supply Source breakage that could contaminate the water stored ○​ Example: Level 3 water systems may need rapid LEVEL 3: INDIVIDUAL HOUSEHOLD CONNECTION repairs or adjustments in order to meet increased ​ Most common type demand ​ There is a source, a reservoir, a pipe distribution ○​ Example: Some water supplies discontinue because network, and individual household taps the treatment plant fails to operate or if it is affected by ​ For high density, built-up areas where homes are close a typhoon together. ​ Water from the water treatment plant will be stored in the Public Health and Safety storage tank (reservoir) and the pipe distribution network ​ We have to ensure that all levels of water supply are will allow the water to reach each home that is connected protected, making sure that the water provided undergoes to the system through one or more faucets installed within adequate and proper water treatment to prevent the household outbreaks of diseases within the community ​ Offers high level of convenience and ensures easy and ○​ Contribute to the overall improvement of public health immediate access to water, making it ideal for urban and densely populated areas (e.g., Metro Manila) RELEVANT POLICIES AND REGULATIONS ○​ It is very common in cities/areas which have access to ​ We have to understand these guidelines to ensure that our water districts or LGU–managed water utilities. water sources are managed effectively and sustainably ​ While this level of water supply is accessible, its consistent availability or stability is NOT guaranteed. CODE ON SANITATION OF THE PHILIPPINES (P.D. 856) ​ Aside from water supply, it also addresses sanitation, industrial hygiene, and food safety PH 136 | Water Supply and Health 3 of 10 ​ Plays an important role in safeguarding the quality of WATER SAFETY PLAN (WSP) drinking water by enforcing the criteria set by the ​ WSP is important because it is a preventive risk Philippine National Standards for Drinking Water management tool to ensure safe drinking water (PNSDW) ○​ When water supply service providers develop and ○​ This document establishes the acceptable levels for implement their WSP, they can proactively identify different water quality parameters: physical, biological, and manage potential hazards (and hazardous chemical, and radiologic events that could compromise water quality) through ​ Outlines two specific types of water examination: the implementation of appropriate control ○​ Initial Examination: Mandatory for all new water measures sources ○​ Involves strategies for continuous improvement for ​ When a new water source is being established, it safety, maintenance of equipment, training for must undergo testing of the four parameters in workers, etc. the PNSDW ​ Development and implementation is the responsibility of ​ For establishing baseline data various stakeholders ○​ Periodic Examination: Entails regular examination for ○​ WSP for water treatment and distribution is typically existing water sources to ensure that water quality is the responsibility of the water supplier acceptable over time ○​ WSPs for buildings is the responsibility of building ​ Frequency is as often as possible while the owners or managers, with support from various other interval must not exceed 6 months stakeholders ​ Water service providers are required to conduct bacteriological testing every month and STEPS IN WATER SAFETY PLAN DEVELOPMENT physiochemical examination every 6 months to 1.​ Formation of a dedicated WSP team ensure compliance with the PNSDW ​ Identify people responsible for the development of WSP ​ Also requires the testing of mandatory parameters ○​ Usually led by the owner or head of the facility, but in the PNSDW can consult other experts ​ The standards of PNSDW are based on international ○​ Define the methodology for the development of WSP guidelines, usually in reference to WHO 2.​ Description of Water System ​ In addition to monitoring and regular testing, Chapter 2 of ​ WSP should provide a comprehensive description of the the Code of Sanitation of the Philippines—specific to water system: water supply—includes other protective measures: ○​ Applicable water quality standards (2017 PNSDW) ○​ Washing clothes or bathing within 25 meters from ○​ Sources of raw water (level 1, 2, 3) any well is prohibited ○​ Storage of raw water ​ If NOT observed, then the water supply source ○​ Identify alternative sources of water (e.g. use of may be may be considered as “high-risk” rainwater during emergencies) ○​ No artesians, deep or shallow well, shall be ○​ Document known or suspected changes in water constructed within 25 meters from any source of quality related to weather conditions or other factors pollution and details about water storage (e.g. if water becomes ​ The regulations found in PD 856 are designed to protect turbid during extreme weather events) our water supply sources from biological and chemical contamination 3.​ System Assessment ○​ However, due to rapid urbanization and population ​ Identify all potential hazards that could affect water growth, it is very challenging for water supply service quality (e.g. contamination, inadequate removal of providers to consistently adhere to these requirements particulate matter, etc.) ○​ Water refilling stations have UV lights to kill NATIONAL POLICY ON WATER SAFETY PLAN FOR ALL pathogenic microorganism still present in water supply DRINKING WATER SERVICE PROVIDERS (A.O. 2014-0027) ​ Assess and prioritize risks ​ Mandates all drinking water service providers (e.g. ​ Determine or assess existing control measures and their Maynilad, Manila Water, water districts, LGU managed effectiveness water utilities, water refilling stations) to develop and ○​ What does the water facility do to ensure that the implement a water safety plan. hazards are controlled or prevented? ○​ Guide developed by water supply service providers to 4.​ Controlling Risks ensure the safety and quality of drinking water ​ Based on the identified hazards, decide whether additional ○​ The Water Safety Plan (WSP) is a risk management control measures are needed to be implemented to tool to prevent the occurrence of hazards in the water manage and mitigate the hazards treatment facilities, refilling stations, etc. ​ Implement and maintain control measures ​ The Order also aims to: ​ Establish operational monitoring programs ○​ Increase awareness of stakeholders on WSP ○​ Evaluate for continuous improvement (updated to approach as a management tool; address new hazards) ○​ Develop, adopt, and implement systems and ​ Define corrective actions procedures for WSP; and 5.​ Verification, Auditing, and Periodic Review ○​ Strengthen the capacity of drinking water service ​ To regularly revise the water safety plan providers and partners in the development and implementation of WSP. ​ DOH is actively involved in the capacity building of water service providers and their partners in the development and implementation of WSP ○​ Through training of water districts and LGU managed water utilities PH 136 | Water Supply and Health 4 of 10  Impurity of zinc coating of Cadmium 0.003 mg/L galvanized pipes and solder and metal fittings Plumbing system containing lead pipes, Lead 0.01 mg/L solder, fittings, or the service connections to the homes Leaching or runoff from agricultural land or Nitrate 50 mg/L contamination from human or animal waste Organic materials, iron and Apparent 10 color units manganese, suspended Color matter Turbidity 5 NTU Suspended matter Operational water quality pH 6.5-8.5 parameter Natural sources, sewage, TDS 600 mg/L urban runoff and industrial wastewater Figure 6. Summary of WSP steps. Disinfectant Residual PHILIPPINE NATIONAL STANDARDS FOR DRINKING Chlorine 0.2-0.4 mg/L WATER (PNSDW) QUALITY Dioxide Chlorine 0.3-1.5 mg/L ​ Water Quality Standards ○​ Legal restriction or limitation on quantities, rates, PRIMARY PARAMETERS and/or concentrations or any combination thereof, of ​ Health significant parameters physical, chemical, biological, or radiological ○​ Chemical impurities directly affecting health through parameters acute or chronic exposure ○​ Non-compliance to standards can result to penalties ​ Site-specific or sanctions ​ NOT universally required: may NOT be tested by water ​ Ex. Water stations are temporarily suspended if supply providers water is positive for E. coli, until source(s) of ​ LGUs may adopt some of these parameters as enforceable contamination are identified and addressed parameters in addition to mandatory parameters if they ​ Coliforms such as E. coli should be absent in identify that these parameters are prevalent in their drinking water supply respective areas ​ See online PNSDW here. ○​ In areas with volcanoes, there are naturally higher levels of arsenic in the groundwater CLASSIFICATIONS FOR DRINKING WATER QUALITY PARAMETERS ○​ Fluoride levels are high in some areas in Cavite. If its level constantly exceeds the maximum allowable level MANDATORY PARAMETERS in the PNSDW, then it can be adopted as a mandatory ​ Legally enforceable - All water supply providers should parameter by the LGU be tested for these mandatory parameters ○​ Soil concentration for pesticides and fertilizers are ​ 10 mandatory parameters listed in the 2017 PNSDW higher in agricultural areas. ○​ Thermotolerant coliform - E. coli ​ Examples: Benzene, Radon, Pesticides (Atrazine, ○​ Arsenic Endrin) ○​ Cadmium ○​ Lead SECONDARY PARAMETERS ○​ Nitrate ​ Acceptability parameters ○​ Apparent color ​ Parameters that render the water unacceptable for drinking ○​ pH ​ Includes operational parameters which affect efficiency ○​ Total dissolved solids of treatment process ○​ Turbidity ○​ pH, a mandatory parameter, is also an operational ○​ Disinfectant residual - Residual chlorine should be parameter because it can affect the effectiveness of present in water to ensure neutralization of the chlorination process (the preference is to treat microorganisms (chlorine dissipates when exposed to water with chlorine at lower pH) air) ○​ HOCl dominates at lower pH ​ Can affect health through acute or chronic exposure or ○​ Hypochlorite ion (OCl-) dominates at higher pH affect the acceptability of water for drinking ○​ Of the two species, HOCl is the stronger oxidant. ​ Indicate the possible presence of other contaminants ​ Examples: Iron, hardness, odor ​ Usually exceeds tolerable values based on local monitoring ○​ Water with iron tastes like rust and appears yellowish data (hence became mandatory) ○​ Hardness → Due to calcium, the ‘hard’ water will ​ Have wide spatial distribution across the Philippines prevent lathering of soap ​ Viable indicators for general quality and stability of water supply EMERGENCY DRINKING-WATER PARAMETERS Table 3. PNSDW Standard Values for Some Physical and Chemical Parameters. ​ The PNSDW specifically identified emergency parameters Parameters Max. Allowable Level Sources to enhance response to critical situations or emergencies Naturally occurring in Arsenic 0.01 mg/L groundwater PH 136 | Water Supply and Health 5 of 10 ​ During emergencies, it is difficult to test all mandatory ​ Microbiological quality of water: parameters, hence the following are the minimum ○​ Given HIGHER importance due to the capacity to standards: cause outbreaks and epidemics ○​ Residual chlorine (0.5-1.5 mg/L) ​ Chemical water quality: ○​ E.coli (absent per 100 mL sample) ○​ Generally of LOWER importance because there is ​ LGU should: more time to take corrective action ○​ Advice the affected community to boil drinking water ○​ Most of the time, diseases only occur with extremely ○​ Monitor the emergency parameters for 7 days high concentrations or long exposures. Additionally, ○​ Supply the drinking water during first 72 hours (critical chemical water contamination is more noticeable due period; no water and electricity) to discrete changes in odor, smell, and taste, thus ○​ Deploy mobile treatment plants addressed right away. ○​ However, acute effects may also be encountered. A MICROBIOLOGICAL STANDARDS AND CHARACTERISTICS major pollution event occurs when levels of certain ​ Microbiological characteristics are typically expressed in chemicals are extremely high (e.g. oil spills, terms of concentration of particular species of bacteria radioactive pollution from nuclear detonation) ​ It is a normal practice to detect and enumerate “indicator ○​ Can also cause irreversible damage to the surrounding bacteria” environment ○​ By convention, coliforms are the most commonly ​ Ideally, both should be given equal attention and analysis. used indicator bacteria ○​ Water is tested for total and fecal (thermotolerant) WATER-RELATED DISEASES DISEASES coliforms WATER-BORNE DISEASES ○​ Indicator bacteria for fecal coliforms: E. coli ​ Transmitted through ingestion of contaminated water ○​ Presence of E. coli indicates contamination of water ​ Water is the carrier of the infectious agent/ pathogen/ with feces from humans and animals → hazardous chemical ​ Total coliforms should be absent or very low ​ Disease caused by the poor quality of water Table 3. PNSDW Microbiological Standards. ​ Examples: MICROBIOLOGICAL STANDARDS ○​ Cholera MTFT