Bluestone Holiday Resort
Case Study: Bluestone Holiday Resort, Narberth, Wales
Domestic sewage treatment plant.
Approximate capitol cost- £550,000. Volumetric consent to discharge – 450mᵌ per day .
Achieved- 99.9% removal of NH4 at 40mg/l – Installation of major upgrades, consistent O+M results during commissioning phase and ongoing.
The existing domestic sewage treatment plant was undersized and unable to cope with the volumes of sewage coming into the plant. This resulted in frequent tankering from the plant to remove raw effluent. This task would have been ongoing for as long as Bluestone was an active holiday village.
JEMS was appointed the main contractor for the installation of upgrade works at the site. Bluestone were looking to install a system that would be able to successfully treat the required volume of sewage from the park and that would meet the consent requirements of National Resources Wales.
This would greatly reduce the tankering costs at the plant.
The existing plant consisted of an inlet pumping station, two primary settlement tanks operating in parallel, a balance tank, two aerobic tanks, two membrane bio-reactors (MBR) and an emergency storage tank.
Consent To Discharge Limitations
- BOD: 20 mg/l
- TSS: 30 mg/l
- NH4-N: 5 mg/l
JEMS managed and engineered the upgrade works, changing the process of the plant also. The MBR system was completely removed. The upgraded plant now consists of an inlet pumping station with inlet screen, a primary settlement tank, an anoxic tank, 3 activated sludge plants (ASP), a final settlement tank (FST) with bridge scraper, a sand filter, a UV screen and a storm overflow tank. The settlement tanks from the MBR plant were utilised as ASP tanks in the new plant. This proved very cost effective.
The system has proved successful in many ways: Firstly, tankering costs have reduced by around 75% as the plant is capable of treating greater flows. Secondly the effluent quality is well within the consent limits at <7mg/l BOD, 5mg/l SS, 0.1mg/l NH4N 5mg/l Fe. Thirdly, the O&M costs have reduced as the plant is no longer operating in crisis mode.These successes resulted in an overall cost saving of £50k per annum to the client.