Identifying ways to reduce water usage and trade effluent generation in any business starts with reviewing processes and creating a step by step Water Efficiency Action Plan.

In big industry, such as the chemical and manufacturing industries, the same simple methods can be used to reduce water usage.

Water Efficiency Action Plan

Produce a Water Efficiency Action Plan that outlines your initial findings, sets out problem areas, priority improvements, targets and timescales. Communicate the plan and potential benefits to everyone concerned and get feedback.

  • Implement the plan using teamwork to generate ‘buy-in’. Maintain interest and motivation with regular communication on progress.
  • Review progress regularly and adapt the plan to take account of business changes or to improve the effectiveness of monitoring.
  • Report success to show the efficacy of the plan and to maintain focus going forward.

When creating your Water Efficiency Action Plan you should consider all the opportunities to reduce water use in your manufacturing centre including:

  • Vessel washing
  • Equipment cooling and vacuum pumps
  • Reusing water from effluent and recovering raw materials
  • Using different sources of water for processes where mains water is not necessary
  • Cleaning and rinsing techniques, process evaluation and process plant techniques
  • Commercial facilities such as washrooms, catering facilities and vehicle cleaning
  • Heating and hot water systems, water meters, leakages and overflows, water pressure and pressure-reducing valves
  • Reducing mains water use through rainwater harvesting
  • Preventing spills and leaks and handling materials securely.

Opportunities for businesses to reduce water usage usually occur when new processes are being designed or existing vessels are being refurbished. However, by being aware of general good practice, you can take advantage of other opportunities when they arise.

Designing for water efficiency

When the opportunity to purchase or redesign new vessels and containers does arise, basic design aspects that you should look for include:

  • Positioning valves at the lowest point to improve drainage
  • Replacing flat-bottomed vessels with vessels with smooth contours and no corners
  • Designing vessels with a cone-shaped bottom to assist drainage and cleaning
  • Fully enclosing vessels to reduce evaporation
  • Using polished stainless steel or plastic-lined vessels to make cleaning easier
  • Carrying out inline monitoring of the wash liquid to optimise the amount of water used
  • Using high-pressure spray wash and cleaning-in-place (CIP) systems to reduce downtime and increase productivity.
  • Sprays as an alternative to fill-and-flush techniques can reduce water use by up to 90%.
  • PH sensors can continually test rinse water and immediately cut rinsing when desired levels are reached.
  • Linking vessels and holding tanks to form a closed-loop wash system makes it easier to reuse wash liquid, and reduce odours and emissions.

Optimising water usage

There are also several ways in which your manufacturing centre can reduce and optimise the use of water in cooling systems:

  • Reuse – depending on the level of contamination, water can often be recirculated or reused, often for cleaning purposes
  • Control use – fit thermostats to cooling circuits to control coolant flow and use only the minimum amount necessary
  • Cooling water composition – prevent build-up of solids and chemicals in water recirculation systems
  • Reduce solids in cooling water – have a settlement or treatment stage in the circuit
  • Condensate – improve recovery of condensate from condensers and steam traps and reuse it for cleaning or dilution

Reducing water usage

You can also reduce water use in liquid-ring vacuum pumps by:

  • Interlocking the seal and cooling-water supply with a solenoid valve to shut off the water supply when the pump is not operating
  • Using alternative seal liquids instead of water, such as organic solvents with high boiling points, reducing the need to purge solids
  • Using dry-vacuum technology such as lobe pumps, screw pumps and claw mechanism pumps.

Reusing water and alternative water sources

Although mains water is often required for many manufacturing processes, you can reuse water or use lower quality water for some applications such as cleaning, toilet flushing and wet air pollution control.

  • Harvested rainwater for cleaning, toilet flushing, etc.
  • Conditioning and softening water using a physical method, such as magnetic treatment, rather than ion exchange to eliminate brine waste.

Cooling waters and some effluents, (treated and, in some cases, untreated), can frequently be reused for other purposes around your manufacturing business, such as toilet flushing and cleaning. Simple treatment methods, such as settlement and filtration, increase opportunities for reuse. With careful planning, it’s sometimes possible to reuse effluent more than once.

By monitoring and evaluating business water use, and employing equipment that facilitates water efficiency, your manufacturing centre can quite easily make impactful savings on its water usage.

Over time, these efficiencies can result in significant cash savings that can free up budget for better use in other parts of your business.