Many development sites, mines, industrial plants, and other projects or activities with an environmental impact may be situated near watercourses, either surface water, groundwater or both. Surface and groundwater resources can be on site or surrounding the site, upstream and/or downstream. Depending on the scope of the development or activities on site, impacts to receiving watercourses can take place which necessitates the need for regular monitoring to take place to identify changes in water quality. Of particular importance is baseline water quality monitoring to be conducted prior to the initiation of the activity. The data obtained during the regular monitoring periods can then be compared against the baseline condition to determine if changes to water quality have occurred. The source of the pollution can then be identified, and adequate mitigation and/or rehabilitation measures implemented to rectify the impact on the water recourse/s.
Impacts to water quality can be surface pollution through contaminants, chemicals, hydrocarbons, waste and other or underground through Acid Mine Drainage (AMD) and other harmful leachates. Where these contaminants enter receiving water resources, environmental degradation can take place and human health may be impacted (SGS, 2023) (CDC, 2020). Both of the aforementioned consequences can carry serious financial and sometimes legal consequence in terms of relevant environmental legislation. This is where regular water sampling and testing becomes important.
Water sampling can be done internally by the developer or mine operator, but some Water Use Licenses (WULs) and Environmental Authorisations (EAs) require an external, independent sampler. Water quality analysis will be done by a South African National Accreditation System (SANAS) accredited laboratory. The reason the laboratory needs to be SANAS accredited is to ensure conformity of assessment of the water quality sample, which is regulated by the Conformity Assessment, Calibration and Good Laboratory Practice Act (Act 19 of 2006) (SANAS, 2023).
When collecting the water sample, the independent sampler will use a bucket or sample bottle which is then closed with a lid and sealed to ensure that only the accredited laboratory breaks the seal to access and analyse the water sample. The sample bottle will need to be labelled correctly with the date of when the sample was taken and the name of the sample for easy identification during analysis (Madrid & Pedrero Zayas, 2007). A groundwater sample is taken from boreholes by use of a bailer or water pump and placed in the correct vessel as described above. All water sampling and analysis needs to be done in accordance with the relevant ISO guidelines as follows:
ISO 5667-1:2008 sets out the general principles for, and provides guidance on, the design of sampling programmes and sampling techniques for all aspects of sampling of water (including waste waters, sludges, effluents and bottom deposits.
ISO 5667-2:2001 Water quality. Sampling. Part 2: Guidance on sampling.
ISO 5667-3:2018 Water quality — Sampling — Part 3: Preservation and handling of water samples.
ISO 5667-4:2016 gives guidelines for the design of sampling programmes, techniques and the handling and preservation of samples of water, from natural and man-made lakes during open-water and ice-covered conditions. It is applicable to lakes with and without aquatic vegetation.
ISO 5667-5:2006 establishes principles to be applied to the techniques of sampling water intended for human consumption.
ISO 5667-6:2014 sets out the principles to be applied to the design of sampling programmes, sampling techniques, and the handling of water samples from rivers and streams for physical and chemical assessment.
ISO 5667-7:1993 Water quality — Sampling — Part 7: Guidance on sampling of water and steam in boiler plants.
ISO 5667-8:1993 Water quality — Sampling — Part 8: Guidance on the sampling of wet deposition.
ISO 5667-9:1992 Water quality — Sampling — Part 9: Guidance on sampling from marine waters.
ISO 5667-10:2007 Water quality — Sampling — Part 10: Guidance on sampling of waste waters (SANS 5667-10-2007 Part 10: Guidance on sampling of waste waters).
ISO 5667-11:2015 Water quality — Sampling — Part 11: Guidance on sampling of groundwaters.
ISO 5667-12:2017 Water quality — Sampling — Part 12: Guidance on sampling of bottom sediments from rivers, lakes and estuarine areas.
ISO 5667-13:2016 Water quality — Sampling — Part 13: Guidance on sampling of sludges.
ISO 5667-14:2016 Water quality — Sampling — Part 14: Guidance on quality assurance and quality control of environmental water sampling and handling.
ISO 5667-15:2016 Water quality — Sampling — Part 15: Guidance on the preservation and handling of sludge and sediment samples.
ISO 5667-16:2017 Water quality — Sampling — Part 16: Guidance on biotesting of samples.
ISO 5667-17:2008 Water quality — Sampling — Part 17: Guidance on sampling of bulk suspended solids.
ISO 5667-18:2001 Water quality — Sampling — Part 18: Guidance on sampling of groundwater at contaminated sites.
ISO 5667-19:2004 Water quality — Sampling — Part 19: Guidance on sampling of marine sediments.
ISO 5667-20:2008 Water quality — Sampling — Part 20: Guidance on the use of sampling data for decision making — Compliance with thresholds and classification systems.
ISO 5667-21:2010 Water quality — Sampling — Part 21: Guidance on sampling of drinking water distributed by tankers or means other than distribution pipes.
ISO 5667-22:2010 Water quality — Sampling — Part 22: Guidance on the design and installation of groundwater monitoring points.
ISO 5667-23:2011 Water quality — Sampling — Part 23: Guidance on passive sampling in surface waters.
ISO 5667-24:2016 Water quality — Sampling — Part 24: Guidance on the auditing of water quality sampling.
ISO/AWI TS 5667-25 Water quality — Sampling — Part 25: Guideline on the validation of the preservation time of water samples (Development).
The Department of Water Affairs and Forestry (DWAF) (1996) (now the Department of Water and Sanitation (DWS)) published the South African Water Quality Guidelines, which outlines various water quality parameters (pH, Dissolved Oxygen, etc) and acceptable limits for each parameter according to the environment and proposed use of water. Depending on the WUL, specific limits may be set which is specific to a particular project or activity. It is therefore the onus of the developer or operator of the activity to ensure compliance with the specified limits. Regular collection and subsequent analysis of water quality samples relative to a development or activity will monitor compliance to the specified parameter limits. Where exceedances are noted, the independent specialist will provide realistic mitigation and rehabilitation measures in an attempt to comply with the specified limits. Should exceedances persist, the relevant Competent Authority (e.g. DWS) may take necessary steps which could have financial or legal implications. Regular water quality sampling is therefore of critical importance to monitor compliance and to ensure early identification of any exceedances.
Environmental Assurance (Pty) Ltd. (ENVASS) offer highly skilled and suitably qualified teams of Environmental Specialist who are always ready to review and implement stringent water quality monitoring programmes for a new project or existing activities. If you require a proposal for these services, please do not hesitate to contact our highly qualified and experienced specialists at ENVASS on 012 460 9768 or email@example.com.
References: CDC, 2020. Importance of Water Quality and Testing. [Online] Available at: https://www.cdc.gov/healthywater/drinking/public/water_quality.html#:~:text=The%20presence%20of%20certain%20contaminants,especially%20at%20risk%20for%20illness. [Accessed 13 April 2023]. Madrid, Y. & Pedrero Zayas, Z., 2007. Water sampling: Traditional methods and new approaches in water sampling strategy. TrAC Trends in Analytical Chemistry, 26(4), pp. 293 – 299.