Case studies

Broomy Hill WTW Aluminium Storage and Dosing Upgrade

General

The works at Broomy Hill included;

A new Aluminium Sulphate dosing system, a new Hypochloride dosing system and a new Aluminium storage system which comprised of the following Elements:

  • 3 new Aluminium storage tanks and bases (supplied by DCWW)
  • New Control & Dosing Kiosk complete with lighting and small power.
  • Bulk chemical delivery and storage equipment.
  • Dosing pumps (Supplied by DCWW) and associated equipment.
  • Instrumentation control panel.
  • Delivery Fill Control Panels.
  • Electrical Installation of Field Cables, Cable Containment, Site Lighting. Trace Heating, and Earthing.
  • Electrical testing of new installation to BS7671.
  • New Dual contained dosing lines to current dosing points.
  • Hardwired links to the new PLC and software.
  • Removal and disposal of existing storage tanks, equipment and bunded area.
  • Installation of facilities to access existing Sodium Hypochlorite storage tank instrumentation.
  • Wash down facilities.


Design Works

The scope of works had been designed by Celtic Process Control Limited prior to award of contract, the only reliant on design were some addition electrical power and profibus requirements.

The sites power cabling was calculated individually using a preparatory design package (Amtec).

Additional design was required for the interface with the newly installed site ICA package.

All of 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, MS102, MS104, MS147, MS154, ES301, ES302, ES303, ES306, ES312, ES319, ES403, ES425, ES426 and PS102.


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.


Civil Works

Welfare and site accommodation was put into place, areas were fenced off and appropriate safety and information signage erected. The existing Aluminium storage tank bund and Sodium Hypochlorite building were demolished and removed from site, the remaining areas were cleaned and returned to general use. All the waste on site was controlled and removed via a licensed waste removal company.


Mechanical Works

3 new storage tanks were installed by the tank manufacturer on previously constructed concrete bases. The tanks pipe work and valving was installed by CPC. 4 in quantity new duty / standby dosing skids - Aluminium Sulphate, Sodium Hypochlorite 14%, 2 x Sodium Hypochlorite 2% were installed, these skids were fabricated on site and were located within a secure steel kiosk (supplied by DCWW) and were designed to fit the contraints of the kiosk. The pipe works was a combination of ABS, PVC and dual Hydrachem hosing, the pumps used were Watson Marlow 520s and the valves used were George Fischer for isolation and Prochem services for control.


Instrumentation

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. In-house instrumentation calibration was for the electro-magnetic flow meters, flow switches, level devices, pressure devices and actuated valves.


Electrical Works

Power and signal cabling was installed complete with suitable containment to meet the diverse needs of the individual areas of the site.

All the power and signal cables were sized according to load / length calculations with suitable protection installed.

Integration with the 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 IIE Regs: BS7671 and DCWW standards.


Documentation

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


Similar Schemes

South West Wales - Preseli WTW - Chlorination upgrade

South East Wales - Sluvad WTW - Sodium Hydroxide Storage and Dosing Scheme

North West Wales - Bretton WTW - RGF upgrade


Sub-Contractors

Tank and Bund demolition - R & R Site Services

ICA / Software contractor liaison - FIM

Minor civil modification - Alpha building services


Discipline : Civil

% split : 11

In House - % split : 75

Sub-Contracted - % split : 25


Discipline : Mechanical

% split : 56

In House - % split : 90

Sub-Contracted - % split : 10


Discipline : Electrical & Instrumentation

% split : 33

In House - % split : 100

Sub-Contracted - % split : 0


Case Study Information
Location:
Broomy Hill WTW, Herefordshire
Start Date:
02/09/13
Duration:
29 weeks
Form of contract:
NEC3 Short Contract Option A
Contract status:
Completed
Contract title:
Broomy Hill WTW Mechanical and Electrical Installation DCWW/409/2012
Contract value:
£257,985.00

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