D3. SCOPE OF WORK
D3.1 The Work to be done under the Contract shall consist of the demolition of existing boilers B5, B5A, B5B and supply, installation, testing and commissioning of two (2) new boilers and associated systems in the existing Boiler 5 room at North End Sewage Treatment Plant (also known as NEWPCC). In addition, the Work includes the replacement of the existing MCC’s and associated work as noted on the electrical drawings.
D3.2 The major components of the Work are as follows:
(a) Supply and install two (2) new fire tube boilers, BLR-B0005 and BLR-B0006, c/w accessories and chimneys. Related works include:
(i) New penetrations in existing roof to accommodate the new chimneys.
(ii) Repair and seal around existing wall penetrations.
(iii) Provide permanent post supports in basement room beneath new boilers to reinforce floor against the weight of the new boilers.
(b) Demolish and remove boiler B5 and associated chimney, piping, electrical, controls, etc. Provide temporary cover for the chimney roof penetration as required.
(c) Relocate existing nitrogen tanks.
(d) Remove boilers B-5A, and B-5B with associated pumps.
(e) Relocate low-flow circulating pump P-B0150 (Previous tag BP-5D.)
(f) Supply and install new boiler hot water piping, consisting of:
(i) New supply and return lines from the new boilers to the new pumps including tie-ins to existing hot water supply/return piping. A hot tap specialist is required to for the tie-ins to existing piping.
(ii) Revise piping serving existing boiler BLR-B0007 (Previous tag B-5C.)
(g) Supply and install new boilers natural gas piping, consisting of:
(i) Upsize natural gas line from 80mm to 100mm to feed new boilers BLR-B0005 and BLR-B0006 as well as existing boiler BLR-B0007.
(ii) Provide new pressure-reducing regulator at each new boiler, and run pressure relief lines from regulators to outdoors, repair and seal around new wall/roof penetrations.
(h) Supply and install new boiler water relief piping, consisting of:
(i) Safety relief separator tank and associated piping and venting. Repurpose old chimney roof penetration for the separator tank vent.
(ii) Run new safety relief valve separator tank into existing main boiler room, and tie-in to existing blowdown tank drain.
(i) Remove obsolete hot water and natural gas piping around existing Boiler 5 as required to accommodate new piping tie-ins.
(j) Supply and install two (2) new funnel drains near new boilers, and new drainage piping to existing sump pit in existing main boiler room.
(k) Provide modifications to existing boiler plant control system to integrate control of new boilers into the existing system.
(l) Provide testing and commissioning of the new boilers.
D3.3 The City is awaiting ITS permission/approval to connect new boilers to the digester gas system (Expected by December 31, 2025). The following Work to be priced under lines 2 and 3 of Form B - Prices. The Work shall not be carried out until written permission is give by the Contract Administrator on or before December 31, 2025.
(a) Separate Price Item 1 - Installation of Boilers BLR-B0005 and BLR-B0006 Digester Gas Service
(i) Install new 100∅ mm. digester gas header in the Boiler 5 room. Tie-in new header to the existing digester gas system isolation valve.
(ii) From the new 100∅ mm. digester gas header, install separate 80∅ mm. digester gas service piping connections to new boilers 5 and 6 digester gas valve trains. Provide new dedicated isolation valve for each boiler service connection.
(iii) Install one new dedicated flowmeter, with associated power and control wiring, on each boiler 5 and 6 digester gas service piping connection.
(iv) Install new digester gas condensate drain piping for each boiler 5 and 6 digester gas valve train. Condensate drain connection locations to the boiler digester gas valve trains shall be coordinated with the boiler vendor. Route condensate piping through the Boiler 5 room basement to new high and low pressure digester gas condensate traps in the main boiler room.
(v) Install new high pressure and low pressure digester gas condensate traps in the main boiler room, dedicated to boilers 5 and 6. Route condensate trap venting to outdoors.
(vi) Demolish existing low pressure condensate drip trap, connected to the digester gas header, in the main boiler room and replace with new high pressure digester gas condensate trap. Route trap venting to outdoors.
(b) Separate Price Item 2 – Boiler 1 and 2 Digester Gas Safety Shutoff Valve Replacement
(i) The following scope of work applies to both existing boilers 1 and 2 digester gas valve trains.
(ii) Demolish and replace the existing digester piping with new, from the dedicated boiler isolation valve, downstream to the existing flame arrester. The existing boiler isolation valve and flame arrester shall remain.
(iii) Demolish and remove existing boiler low pressure digester gas condensate traps.
(iv) Install new digester gas strainer.
(v) Install new digester gas pressure regulator.
(vi) Install new digester gas pressure relief valve. Route relief valve venting to outdoors.
(vii) Install new digester gas differential pressure flowmeter, complete with new tapped flanges and orifice plate. Connect new flowmeter to existing flow transmitter. Existing flow transmitter and associated control and power wiring shall be retained for reuse.
(viii) Demolish and remove existing digester gas safety shutoff valves. Retain existing power and control wiring for reuse. Install two (2) new flanged digester gas safety shutoff valves. Reconnect existing power and control wiring to the new valves once they are installed.
(ix) Demolish and remove existing digester gas automatic vent valve, with associated vent piping. Retain existing valve power and control wiring for reuse. Install one (1) new automatic vent valve. Install and route new vent piping to atmosphere.
(x) Install new piping connections and bleed vents for existing low pressure switch and high pressure switch. Existing low pressure and high pressure switches, with associated wiring, shall be retained for reuse.
(xi) Install new high pressure digester gas condensate drip trap, connected to new strainer blowdown port. Route trap venting to outdoors.
(xii) Install new portable low pressure digester gas condensate drip trap at low point of digester gas valve train.
(xiii) Install new portable low pressure digester gas condensate drip trap, connected to the existing flame arrester.
(xiv) Install new digester gas ancillary accessories including pressure indicators, pressure test points and purge points.
(xv) Commission and verify performance of new digester gas valve train and associated systems, including new safety shutoff valves, automatic vent valve, flowmeter and existing transmitter, pressure regulator, relief valve and existing high pressure and low pressure switches.
D3.4 The following shall apply to the Services:
(a) City of Winnipeg Green Building Policy: New City-Owned Buildings and major additions;
http://clkapps.winnipeg.ca/DMIS/DocExt/ViewDoc.asp?DocumentTypeId=2&DocId=5989
(b) Universal Design Policy
http://clkapps.winnipeg.ca/DMIS/DocExt/ViewDoc.asp?DocumentTypeId=2&DocId=3604
