Northumbrian Water Projects

Sludge Recovery Solutions

Northumbrian Water Projects Ltd. is a division of Northumbrian Water responsible for the long term operation and maintenance of waste water treatment assets in Cork City and County, Ireland.

Client Issue

Sludge recovery solution required

Northumbrian Water Projects Ltd. (NWPL) required a sludge recovery solution for thermally treated sludge granules from the waste water treatment plant (WWTP) in Carrigrenan, Cork City, Ireland.

We recruit farmers, carry out soil analysis, map the farm, draw up NMP’s and manage the collection, storage and landspreading of sludge. 

Enva Approach

Organic fertiliser with detailed Nutrient Management Plans

All thermally treated granules (Biogrow) are recovered for controlled use as a fertiliser on agricultural land. Enva have allocated sufficient land from their national landbank for the recycling of these biosolids.

To spread sludge to land, a Nutrient Management Plan (NMP), must be drawn up to track nutrients in the sludge so as to ensure there is no over-application to land. An NMP for each farm is submitted to the environment section of the relevant local authority, and is fully approved prior to any landspreading. The nutrients we track are Nitrogen (N) and Phosphorous (P). The Nutrient Management Plan is field specific and the application rate of sludge is based on:

1.     The baseline fertility of the soil, attained through soil analysis,

2.     The specific crop requirement

3.     The amount of nutrients in the sludge.

Every individual load of biosolids collected from Carrigrenan Waste Water Treatment Plant is recorded using a docket and weight system and every load is signed off by the driver and the plant caretaker.

Occasionally, NWPL supplies dewatered sludge (Biocake) which is also recycled by Enva.

Results

Secure and tightly controlled recovery solution

The service offered to Northumbrian Water Projects Ltd by the organics team in Enva is a full recycling service. We recruit farmers, carry out soil analysis and map the farm, draw up NMP’s and manage the collection, storage and landspreading of sludge.