On average industry discharges between 60% and 80% of the water they intake as wastewater. A costly exercise as this wastewater not only has to be offset by further intake of water into the system but the external treatment and disposal of this resultant wastewater stream holds a significant charge.

When considering the price of water in capital evaluations industry often neglects to calculate the ‘true’ cost of water. This ‘true’ cost should at a minimum include the supply charge (the rate placed on a kilolitre of water by the water service provider), the cost of any secondary water treatment (if required), the cost of treatment before discharge to ensure in specification effluent (and avoid fines) and the charge placed on the external treatment and disposal of waste water (generally calculated by the municipality based on volume and quality). For many industries the per kilolitre rate placed on water supply (commonly in the region of R25 for large water users in South Africa’s industrial areas) can be doubled to obtain the operation’s ‘true’ cost of water. Often ignored is the cost of potential production shutdowns resulting from external water supply interruptions and not considering water efficiency and / or recovery in future planning is unsustainable for industry. Calculating the ‘true’ cost of water significantly strengthens the business case for water efficiency and water recovery initiatives as sustainable and cost effective options.

As an example an operation that discharges 80% of its water supply as wastewater has the opportunity to halve its external water supply requirements. Thereby not only significantly reducing the water supply bill but also potentially reducing the discharge bill by 50% or more. This is an increasingly lucrative opportunity in South Africa which is expected to experience a rapid escalation in the price of both water supply and wastewater discharge in order to fund the infrastructural upgrades required to meet current and future demand.

Historically, water recovery has not been popular with industry due to perceptions around the quality of water recovered and the possible reputational impact of using recovered water within products. These concerns can be totally negated by channelling recovered water to non-product related activities, such as clean-in-place (CIP), steam, cooling and other utilities.  This also allows for the quality of recovered water to be specified, increasing the potential volume recoverable and decreasing the cost further.

The negative perceptions regarding recovered water in some industries, which has limited the appetite for water recovery are often unfounded, as the quality of recovered water can equal, or in many instances, exceed that of water supplied by the water service provider.  Furthermore, the reputational impact of being a poor water steward is increasingly more relevant than that of using recovered water in products.

By Helen Hulett

(as featured in TAPPSA, Quarter 1, 2018)