Page 10 - Guide to Managing Trade Effluent - 2023

Options for Cost Reduction
Modifications/upgrades to a site’s existing effluent treatment plant increases the opportunity to
reduce costs though a number of routes, such as:
• Decreased operator intervention via increased levels of automation.
• Reduced effluent treatment costs.
• Reduced waste disposal costs.
• Reduced water consumption through increased rates of water recycling.
• Reduced trade effluent charges.
• Reduced waste disposal costs.
• Reduced maintenance costs.
There is a potential that the financial savings made will pay back the capital investment within a
short period of time; increasing the overall profitability of the business.
Planning for Changes to the Operating Process
Where there is a planned change in the nature of the process to be undertaken at a facility
the impacts which the change may have on the ability of the sites effluent treatment plant
to cope with the change, ensuring that the site remains compliant needs to be assessed with
modifications/upgrades built into the program for completing the planned operational changes.
Key points which need to be addressed early on in the planning process are:
• What effect will the planned change have on both the peak flow rate needed to be handled
by the effluent treatment plant and the total volume of effluent that will need to be altered.
• Will the composition of the effluent change, that is will new pollutants be introduced that need
to be treated and/or will the strength (concentration) of the effluent become changed.
• Does the existing trade effluent consent need to be amended and will the sewage undertaker
use this opportunity to impose, new or amended stricter conditions on the quality of the effluent
that can be discharged.
• Will the existing plant be able to operate and ensure that the treated effluent discharged into
the sewer remains compliant with the discharge conditions.
The development of a new production capability and the assessment of the requirements to treat
the effluent need to be made concurrently.
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Ten Steps to Becoming Water Efficient
Step 1 Engage all staff and senior management in your water saving programme.
Step 2 Identify how much your business is paying in water and wastewater charges and also what hidden charges
your business is facing.
Step 3 Develop a water balance for your business attempting to quantify >90% of water use.
Step 4 Use the information in your water balance to design a Monitoring & Targeting (M&T) system.
Step 5 Use your water balance and M&T system to identify improvement actions to eliminate or reduce water use and
minimise effluent generation (strength and volume).
Step 6 Identify water saving techniques that will allow these water saving opportunities to be realised.
Step 7 Prepare a Water Efficiency Action Plan (WEAP) to summarise and prioritise improvement actions including
a business case for each action then implement them as appropriate. Regularly update your WEAP as new
improvement actions are identified.
Step 8 Review and evaluate the actual improvement action benefits achieved.
Step 9 Communicate success to staff, senior management and your supply chain to maintain their engagement.
Step 10 Continually improve by returning to step 2.
Increasing Production Capacity
Increasing the production capacity of a facility often increases both the instantaneous rate and/
or the volume of effluent which may be generated. These increases may exceed the treatment
capacity of the existing treatment works creating a need to increase the capabilities of the
existing treatment plant.
Prior to committing to capital works program to increase the size of the sites existing effluent
treatment capability it is prudent to understand:
1. Can the existing plant be optimised so enabling a greater amount of effluent to be treated by
the existing effluent treatment works;
2. Is the capacity of the existing effluent treatment plant to treat the effluent limited by the peak
or average effluent flow rate. Where the plant is limited by the peak flow rate conditions, can
temporary effluent storage be put in place, reducing the peak flow to a level that the plant
can cope with;
3. What can be done to limit the amount of effluent that is discharged into the sites foul drainage
network. For example, can a program of water use reduction be implemented that will reduce
the overall volume of effluent that needs to be treated. If so what effect will these efficiency
measures have on both the volume of effluent and its composition have. Will reducing the
volume of the effluent have the effect of increasing the strength of the effluent? This may have
the unexpected effect of making the effluent more difficult to treat.
Prior to committing to capital expenditure it is important to understand what it is that is limiting the
capacity of the existing effluent treatment plant. The capital improvement works need to correctly
focus on the needs of the site, and cost effectively provide the needed increase in treatment
capacity.
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