One of Europe’s largest abattoir companies needed a new highly reliable effluent treatment facility in UK as part of a business expansion plan. The treated effluent needed to be of a sufficiently high quality that it could be discharged to a local stream.

The Challenge

The new effluent treatment plant needed to ensure that the treated effluent would produce high-quality that would not damage the local habitat as the effluent was to be discharged to a local stream.

Keeping within the EPA consented discharge limits was also a major criteria for the client who also wanted to recycle up to70% of the treated water for site cleaning.


The initial step was to fully analyse and understand the site requirements and daily production levels. Specific attention was paid to the organic loading in the wastewater stream. Site requirements were gathered not only for current treatment levels but also for predicted flows and contaminant loadings.

Part of the assessment included visiting and analysing data from other of the client’s sites. Senior management were then consulted regarding the proposed design of the new wastewater treatment plant.

Once the site and comparative data had been evaluated, Hydro proposed the following treatment steps to address current and future loadings: an automatic grit removal system, inlet fine screening (1mm), balancing tank, chemical DAF, aeration tank, de-nitrification, MBR clarification, sludge dewatering RO filtration and water sterilisation. The latter two steps facilitated the recycling of 70% of the treated flow.

Once client sign-off had been received for the proposed design, Hydro began building the new treatment plant.  The timeframe from design sign-off to plant start-up was 5 months.


Due to the success of the plant, the client was awarded the Green Apple award (the highest award in Europe for environmental design).

Parameters Raw Water After MBR Final  (After RO)
Flow 15 m3 15 m3 15 m3
BOD 1618 mg/l 5 mg/l 0 mg/l
COD 2375 mg/l 80 mg/l 2 mg/l
NH3-N 45 mg 1 mg 1 mg
Nitrogen 45 mg 1 mg 2 mg
Suspended Solids 1543 mg 2 mg 0 mg
Phosphorous 11 mg 0.05 mg 0 mg
Fats, Oils, Greases 65 mg 0.05 mg 0 mg

Treated effluent continues to remain well under the EPA stipulated licensing requirement and the client now has the option use up to 70% of the treated effluent for various uses on the site.

Hydro has now completed fifteen wastewater treatment plants for sites in the client’s group of companies.