Avondale Foods effluent treatment - Case Study
Avondale Foods (Craigavon) Ltd. is one of the UK's leading manufacturers and suppliers of coleslaw, wet salads, side salads, vegetable accompaniments, soups, sauces and mayonnaise to retail and foodservice customers throughout Britain and Ireland. The company has a team of over 380 people working in its state-of-the-art facility, with all products being manufactured on the same site Avondale Foods installed an effluent treatment system in 2005 to treat all trade effluent produced on site. Over time as production on site has increased, so too has effluent volumes and contamination levels.
Although rarely breaching discharge consent limits, the management team at Avondale Food were conscious that the quality of effluent being discharged to sewer was compliant, but not as good as it once was, leading to increased effluent discharge costs.
Main issues experienced by Avondale Foods;
- Higher contamination levels within the effluent discharged to sewer, have resulted higher charges being imposed by NI Water through their mogden formula trade effluent billing calculations.
- Due to ongoing large scale projects within the production facility combined with day to day maintenance and repair work within the factory, The Engineering Team had limited resources or time available to tackle the improvement measures required at the effluent treatment plant.
- The company that originally installed the effluent plant have stopped trading, resulting in no existing technical support for scheduled service calls or equipment repair.
Water Tecnik Ltd. were contacted directly by Avondale Foods to discuss options around process improvements and to implement a planned approach to ensure improved and consistent effluent standards.
Following several site visits with Avondale Foods Senior Management and Engineering team a finalised action plan was agreed. The main areas for improvement were identified;
- Upgrade and recalibration balance tank level controls, resulting in inadequate flow balancing prior to DAF treatment.
- Measurements indicated flow balancing had a negative effect on DAF chemical dosing control, making consistent chemical treatment difficult to obtain.
- Improved white water system fitted to existing DAF plant, resulting in optimum air to solids ratio within the DAF system.
- Older technology polymer makeup and dosing system, replaced with modern and reliable system resulting in improved dosing.
- Increases size of final effluent transfer pumps eliminating high level control issues.
- Several general maintenance tasks to improve overall performance such as pump refurbishments, new pipe manifolds etc.
Water Tecnik systematically worked through all the identified problems listed above. Most notably we replaced the existing DAF white water system with our own innovative micro-bubble generator white water system.Chemical treatment evaluation
During the process improvement project Water Tecnik also performed Chemical Jar tests on the effluent to ensure that best and most cost-effective chemicals were being utilised within the treatment process. Correct chemical selection can have implications on both plant performance and operational costs.
The work identified and completed by Water Tecnik on site cost Avondale approximately £24,500, over a 3-month period. The improvements in treatment and process reliability have resulted in the following benefits;
- Cost per m3 to discharge effluent dropped 57%
- Through our efforts jar testing the incoming effluent we identified a more cost effective treatment regime. This lowered chemical costs by 49%.
- Plant reliability has improved tremendously, which has reduced the time the engineering department need to spend on repairs. For example, the poly system would have blocked at least once per week, it hasn’t blocked once since modification 3 months ago.
- Effluent discharge is consistently below discharge consent limits.
Avondale Foods have entered a full maintenance and chemical supply agreement with Water Tecnik. We now provide full technical and engineering support for the effluent treatment plant on site.
We normally provide maintenance contracts to our existing customers who have installed a Water Tecnik effluent treatment system. This is the first time we have provided a service agreement to a customer with an existing system in place.
We are delighted with how effective the improvements have been, and that our client could enjoy such instant operational and financial savings.