6. Protecting Drinking Water Quality
Drinking water in BC communities comes from a variety of surface and groundwater sources. There are diverse pressures and challenges to be considered when planning and managing for drinking water quality. These include a wide variety of point sources (e.g. wastewater discharges from sewage treatment, commercial and industrial facilities) and non-point sources (e.g. runoff from urban development, agriculture, forestry and other land uses) of pollution. Natural processes, such as flooding, landslides, erosion and sediment transport can also impact water quality with turbidity and water-borne pathogens (such as E. coli, Cryptosporidium, and Giardia). It is also important to consider the impacts of climate change when planning and managing for drinking water in BC.
Healthy watersheds can contribute significantly to clean surface and groundwater sources because healthy watersheds purify water, and vegetated riparian areas filter and process pollutants such as heavy metals, oils, sediment and waste products. Aquatic ecosystems, such as wetlands and rivers, filter water, allow for the deposition of suspended sediments and provide extra water storage capacity in times of high precipitation. Natural states of land cover, such as forest ecosystems, also help to naturally manage stormwater runoff and reduce flooding risks, and provide important habitat for fish and wildlife. When the health and functionality of a watershed is compromised by human intervention, changes to water quality can occur and additional planning and management may be needed.
The primary responsibilities for protecting water quality are shared by all orders of government including federal (departments of Aboriginal Affairs and Northern Development, Environment, and Fisheries and Oceans), provincial (ministries of Health and Environment), regional health authorities, First Nations, municipalities, regional districts, other water suppliers. When you consider the variety of pressures on water quality, we all have roles in the protection of water quality. The roles and responsibilities for drinking water treatment vary across the province, but lie primarily with municipalities, regional districts, or other water suppliers, with oversight by the BC Ministry of Health and Regional Health Authorities.
Types of Planning for Protecting Drinking Water Quality
This section of the guide profiles three specific types of plans:
- Well (Aquifer) Protection Plans
- Source Water Assessments and Assessment Response Plans
- Drinking Water Protection Plans
Three types of plans may be developed to assist with the protection of water quality in British Columbia. Drinking Water Protection Plans are established under the provincial Drinking Water Protection Act by the government to prevent a substantial threat to water supplies that would result in a health hazard. Also under the Drinking Water Protection Act, an Assessment Response Plan can be required if a Drinking Water Officer, orders a water supplier to prepare an assessment where potential threats to water quality have been identified, that might adversely impact water supply. Well Protection Plans, which may also be a requirement under the Drinking Water Protection Act, are developed to minimize impacts of land use activities on groundwater supplies that are used by community wells. Well Protection Plans can be expanded to the protection of entire aquifers, or perhaps multiple aquifers. For this reason, these plans are referred to as Well (Aquifer) Protection Plans in this guide. Section 7 of the guide explores the scope and value of water, watershed and stormwater management plans, which are also relevant to the protection of water quality.
Why Plan for Protecting Drinking Water Quality
In anticipation of and/or response to mounting challenges, pressures and changes in their watersheds, it is important for BC communities to plan for protection of their drinking water. Water planning can help BC communities understand and address current and expected challenges by improving knowledge about threats to water quality. Protecting source water and drinking water quality is primarily about ensuring that point and non-point sources of pollution do not adversely impact water for human consumption. Source water includes surface waters, aquifers, or groundwater recharge areas.
For an overview of roles and responsibilities for the protection of drinking water quality see the Ministry of Health website for Drinking Water Quality.
Considerable time, money and effort go into treating water and wastewater to protect water quality for various uses. Recently, attention has turned to the importance of protecting water sources as a fundamental approach to managing water quality. Source water protection seeks to identify means of preventing, minimizing, or controlling potential sources of water pollution. It is the first step in a multi-barrier approach to drinking water protection, which provides benefits on a watershed scale by protecting public health, ecosystem functions, and a variety of social, economic, cultural and spiritual values.1 Figure 2 illustrates different components of a multi-barrier approach to protecting drinking water. For information on the multi-barrier approach see the Interior Health Authority website on Drinking Water Source Protection and Multiple Barriers of Drinking Water Health Protection.
Figure 2. Components of a Multi-barrier Approach to Drinking Water Protection. 1
In many cases other water uses, such as those related to agricultural, commercial, institutional and industrial operations, are connected to drinking water supplies. In addition, there are many ecological, recreational and other non-consumptive water uses that must be managed along with drinking water supplies. Often, protecting drinking water can have important co-benefits related to environmental, cultural, spiritual and aesthetic values.
Desired outcomes of water quality planning may include:
- ensuring a safe, secure supply of quality water for a wide variety of uses;
- ensuring that water supply is robust and resilient to climate change impacts and other factors;
- managing wastewater discharges to be within the capacity of receiving waters to absorb and assimilate wastes;
- managing land and resource development practices (and day to day human activities) in ways that maintain and protect water quality;
- practicing urban and rural development in ways that do not adversely affect natural processes (e.g. leaving floodplains in natural states and promoting natural functions such as sediment transport); and
- raising public awareness of the value and importance of fresh water.
Because these planning processes consider threats to water quality, they present opportunities to consider the impacts of climate change along with other pressures on water quality.
Community Watersheds (CWs) are another potential watershed planning unit for consideration in some areas. The province has established 467 CWs in response to the Forest and Range Practices Act, (Government Action Regulation) which provides an added level of protection for water quality in association with forestry operations. However, more research may be required to determine whether there are CWs with completed watershed plans, or there is a desire, capacity and benefits associated with watershed planning at this scale.
Challenges and Pressures
Water quality is a significant issue in some communities, particularly where there are threats to, or pressures on, community water supplies. In some regions in BC drinking water treatment capacity is limited due to supply issues, and the health of aquatic ecosystems is threatened by point or non-point sources of pollution.
For some local governments meeting provincial drinking water standards is a challenge. All BC Health Authorities are required to meet or exceed the Guidelines for Canadian Drinking Water Quality. The Vancouver Island Health Authority developed its own interpretation of the guidelines with the introduction of the 4-3-2-1 Initiative. This initiative is now used by Health Authorities across BC to ensure compliance. In some communities, compliance with the guidelines will require the installation of new treatment plants, which can be a considerable added cost. Because the pressures on water quality are so diverse, ultimately it is everyone’s responsibility to take care of our water resources, including protection of water quality at the source.
Boil Water Advisories
Boil water advisories are issued to residents and other water users when a drinking water source is contaminated or there is a known risk of contamination. Advisories consider the water source, water quality, and distribution and filtration processes. Therefore, the number of boil water advisories issued reflects both the quality of drinking water sources in the area and the adequacy of treatment systems to provide clean water. Over the past decade, the number of boil water advisories in BC has increased. This may be due to several reasons related to actual deterioration of water quality, or greater focus on monitoring and attention to risk. In 2008, the BC Ministry of Health documented 530 boil water advisories. Most of those advisories were on smaller water systems that were serving between 15 and 5000 people.ii
Land Use and Non-Point Sources of Pollution
Urban, industrial and agricultural activities can pose serious threats to water quality. These land uses are associated with a variety of pollutants including nitrates from manure and synthetic fertilizers applied to agricultural lands, sedimentation from eroding soils and stream banks through urban development, and toxic chemicals from a variety of industrial, commercial and household sources. Development activities near shallow wells or above unconfined aquifers (e.g. aquifers that do not have an impermeable layer above them to protect the water from surface pollutants), increase the risk of contamination, and are of particular concern.
Presently, no permits are required to drill a well or extract well water in BC. This lack of groundwater regulation is a key challenge; however, this may change with modernization of the Water Act. Drinking water quality concerns may be elevated in communities that rely primarily on groundwater sources. This is because groundwater sources are difficult to clean once contaminated, contamination can more easily occur without anyone knowing about it, and because they require more time for natural recycling and replacement of water than do surface water sources. Therefore, once water quality is degraded, it takes much longer for contaminants to be diluted or removed. This is a concern to communities such as Langley BC, which sources 80% of its drinking water from wells.
Source Protection and Upstream Activities
In many cases, resource-related activities on private and Crown lands, such as forestry, ranching, agriculture and mining, can effect nearby or downstream community water supplies. Often these activities take place “upstream” of community water supplies, and may be outside of the jurisdiction of local or regional governments. Typically, local governments do not have the authority to regulate or stop these resource practices. There is also a limitation of government authority when it comes to agriculture even within local government boundaries. For example, farm bylaws require approval by the Province of BC before coming into effect.
Climate change is impacting, and will continue to impact, water quality through a variety of mechanisms throughout BC. Increased frequency and severity of drought and flood events, low summer flows, warmer freshwater temperatures, reduced dilution / assimilative capacity, and increased erosion, turbidity and sedimentation are just a few examples. These and other climate-related impacts should be addressed in plans that consider medium to long-term pressures on water quality. The plans should develop solutions for dealing with those pressures. See sections 3 and 9 of this guide for information, tools and resources about climate change impacts on water, related community vulnerabilities and risks, as well as considerations about how climate impacts can be managed through water and watershed planning as well as adaptation.
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PROTECTING DRINKING WATER QUALITY