The works at Court Farm included RGF outlet actuated and hand valves, domestic inlet penstocks, service water tank, UPS and distribution boards for the RGF outlet valves, Emergency Shutdown System, lime dosing flow meters, ferric dosing flow meters, poly and ferric flow switches, poly batching unit, coagulant dosing control, trace heating of the coagulant system and pulsator No2 refurbishment was added during the contract period.
The scope of works had been 90% designed prior to the award of contract and electrical power requirements were the only outstanding area.
The site power cabling was calculated individually using a preparatory design package (Amtec).
Additional design was required on discovery of an access issue to the raw water pulsators and new access doors were needed to be installed for safer cleaning of the pulsators.
All the design works were in compliance with current health & safety regulations and best practice, IEE wiring regulations BS7671, WIMMES, DCWW Specifications and Standards with particular attention to the following; MS101, MS104, ES101, ES319, CS501 and PS117.
Health & Safety
This scheme was notified to the HSE and an F10 was posted. Celtic Process Control was appointed as Principal Contractor. A Health & Safety Plan (Construction Phase) was written, approval was granted for the plan by the CDM Coordinator and the plan was managed safely throughout the duration of the scheme. Specialist training was required for the scheme which included confined space training and both entry and rescue teams these were required for works inside the Pulsators, RGF and domestic filters.
Welfare and site accommodation was put into place, areas were fenced off and appropriate safety and information signage was erected. Pulsator No 2 at Court Farm was refurbished, this consisted of replacing the existing flow boards, cleaning the sludge from the pulsator and coating the pulsator walls and floor with a specialist coating. The access to the pulsator for cleaning was hazardous and an alternative safe solution was required, this consisted of a new access door being cut into the pulsator wall. All the waste on site was controlled and removed via a licensed waste removal company.
The RGF and domestic outlet valves had become unreliable and had to be replaced with new 300mm plug valves and 400mm penstocks respectively, this work required individual shutdown and isolation of the filters and installation of a bespoke lifting system in order to install the 300kg valves into position in a confined space.
The service water tank was not in service and new 2″ PVC pipework and electrically operated actuators were required to commission the service water plant, this was completed, retested and commissioned.
Eight new small bore (1/2″) PVC pipe ferric sulphate dosing skids were fabricated in Celtic Process Controls workshops and then installed on site. These skids were required for the installation of new dosing control flow meters for the existing ferric sulphate dosing system.
The instrumentation for this project was specified by DCWW in their tender package, these instruments were crosschecked (as agreed) against data sheets then ordered by Celtic Process Control for installation.
A wide variety of instrumentation was required, which required the use of experienced in-house technicians and some specialist brought in assistance. In-house instrumentation calibration was for the flow meters (electro-magnetic and ultrasonic), flow switches, level devices, turbidity monitors, conductivity monitors, UPS system, actuated valves, and temperature control boxes. Brought in assistance was from ABB for the coagulant control monitor and Oasis Software Solutions for integration of the ESD system.
Power and signal cabling was installed and completed with suitable containment to meet the diverse needs of the individual areas on the site.
All the power and signal cables were sized according to load and length calculations with suitable protection installed.
Integration with existing site systems as always can be challenging this was overcome by knowledge and experience of the site and in DCWW systems and procedures for safe isolations.
All the electrical works were carried out to meet the current IEE Regs: BS7671 and DCWW standards.
A full document package was produced for each area on site containing the following documents;
- NICEIC electrical test certificates
- Block Cable Drawings
- Instrument Loop Drawings
- Instrument Calibration Certificates
- Manufacturers Inspection /Test / Calibration Certificates
- Hydraulic Test Certificates
- SAP data sheets
This project was carried on throughout the whole of Wales covering all the geographical regions;
South West Wales Crai WTW – OSEC upgrade
North Wales – Llannor WPS upgrade
RGF and Domestic filter outlet valve installation – Penarth Industrial Services
ESD integration – Oasis Software Solutions
Pulsator Coating – CE Barry
Coagulation control – ABB
Discipline : Civil
% split : 11
In House – % split : 10
Sub-Contracted – % split : 90
Discipline : Mechanical
% split : 30
In House – % split : 10
Sub-Contracted – % split : 90
Discipline : Electrical & Instrumentation
% split : 57
In House – % split : 95
Sub-Contracted – % split : 5