Water, Sewage & Effluent May-June 2017 - Page 13

Outcomes and findings Water sustains life and it is in public interest that the water supplied by the public utility conforms to required water quality guidelines. Specialist teams determine these and the treatment process is designed according to the raw water supply. Regular monitoring of the raw water source, the treatment process steps themselves, and the final water quality produced are the only items of evidence that the utility can produce to assure consumers that the water treatment process indeed meets all the required targets that have been set. When dealing with DPR, the utility should keep one major risk in mind: one incident that can be proven to stem from the DPR, where people in the community have been severely compromised (death or serious suffering, mostly caused by acute infection), will lead to a high probability that the treatment unit may be closed, or that financial losses will occur owing to lawsuits. During periods of investigation, the treatment unit will most probably not be allowed to operate. With all this said, it is in the interest of the owner and operator of the DPR to ensure at all times that good data is produced from a robust monitoring programme. The higher cost of monitoring can be compared to an insurance policy: once any doubt occurs, it will prove its value to ensure to the public as well as any panel of judges (either in court or in the media) that the treatment unit complied with all set guidelines and regulations. This policy is a proven one practiced in Windhoek since the first DPR came into operation in 1968. With the upgrades and extensions of capacity of the DPR scheme in Windhoek, monitoring was intensified. With numerous water quality issues mainly caused by natural sources not complying, the public could be convinced that DPR tec hnology (monitoring is an integral part of it) is functioning well and is not causing any threat. As with an insurance policy, it provides peace of mind to the operational staff component, because it proves their commitment. This is one of the reasons ensuring that both the citizens of Windhoek, as well as the owner and operator of the DPR, are proud of their reclamation scheme. In the July/August issue of Water, Sewage & Effluent, we will publish the second part of the Report to the Water Research Commission. u technology The identification and selection of all the water quality constituents and other aspects to be included in the guidelines document were performed. The status of water reuse for potable purposes (direct and indirect) for planning and regulatory purposes was determined from various sources implementing or planning the implementation of water reuse. This was followed by the development of baseline sources and concentrations of selected critical constituents (key parameters), focusing on any improvements that may be necessary to reduce the risk of raw water source quality deterioration and quantity problems, such as the use of reliable online measurements as early warning systems. Standardised terminology for water reuse, including direct potable reuse as well as indirect potable reuse, was developed in conjunction with the relevant stakeholders. The influent monitoring systems were considered, which include constituents, parameters, and monitoring systems, while the focus was on the potential benefits of various influent monitoring schemes that may be used for early detection of constituents. Key factors were considered on how monitoring systems should be designed in relation to process design for the various unit treatment processes in direct and indirect potable reuse to maintain the treatment barriers, that is, the prevention of break- through by pathogens, organic substances, and other micro-pollutants. A selection of constituents and parameters that require monitoring in the final water (those known to be harmful to humans) was performed. This included parameter details, health impacts, analytical methods, and detection limits, while the ‘minimum’ monitoring programmes developed in the project were also coordinated with the Blue Drop programmes (for the water reclamation plants), and the Green Drop programmes (for the wastewater treatment plants feeding the water reclamation plants). A database was compiled of towns in South Africa having direct and indirect potable water reuse potential. Also, a database was compiled of South African laboratories that can perform the various physical, chemical, and microbiological analyses required for water reclamation compliance measurements and research purposes. This was done in cooperation with DWA’s (currently DWS’s) Regulation Directorate, which has already developed databases with information on available laboratories and accreditation status thereof. Using all of the information gathered during the project, and incorporating existing knowledge elsewhere, a concise guideline document was compiled for use by municipalities, water professionals and other stakeholders. Methodology As with an insurance policy, it provides peace of mind to the operational staff component, because it proves their commitment. Water Sewage & Effluent May/June 2017 11