2. Atkins Report - Background

2.1. Existing Pumping Station & rising main

The existing underground pumping station is located along Holywell Way to the East of the Holywell development. The pumping station was designed and constructed to service the 3 phases of the Holywell Development. In its current location the existing pumping station is fed by gravity and pumps effluent via a 150mm dia rising main to the public foul drainage network along the R125. From the R125 the waste water discharges to the Swords Waste Water Treatment Plant located at Broadmeadow Estuary, Swords, Co. Dublin. The existing services located within the area of the existing pumping station are indicated on drawing C006.

During a review of the overall Holywell Development for the purpose of taking in charge, FCC determined that the existing foul pumping station which is located to the North of Holywell Way, was not installed in the position as indicated in the original planning compliance. The existing pumping station is located approximately 2m from the nearest property boundary, and only provides for approximately 6 hours emergency storage. Foul Pumping stations of this size should be located no closer than 15m to a property boundary in order to minimise the risk of odour, noise and vibration nuisance. Pumping stations should also include for the provision of 24 hour emergency storage in keeping with industry best practice.

The as constructed drawings provided by FCC indicate that the existing pumping station is constructed of cast in-situ concrete. The pumping station comprises of a wet well and valve chamber. The wet well is circa 5.3m deep with an inlet invert of 19.8mOD and a wet well invert of 18.1mOD which can cater for up to 3No. 50Hz pumps. Access to the wet well is via 4No. ductile iron covers of class D400 loading. The existing valve chamber also caters for a Mag flow meter DN150.

2.2. Existing Control Building

The as constructed drawings provided by FCC indicate that the existing control building associated with the pumping station is located adjacent to the pumping station. It is used to house telemetry and monitoring equipment for the pumping station and also allows for isolation of the pumps and electrical equipment during maintenance. The existing building is approximately 3m x 3m x 2.4m high with a vent stack of circa 5m high to the rear of the building.