Thomas/Wright, Inc.

Project Examples

Pump Stations Equipment Retrofit - Portland, Oregon
Thomas/Wright, Inc. prepared the plans and specifications for the equipment retrofit at five wastewater pump stations for the City of Portland.

The Argyle and 13th Pump Station involved the addition of an engine-generator set for standby power to a 23-year old, 2.3 MGD pump station. The design included the installation of a 125 KW diesel fueled engine generator set to provide power during utility power outage. Also included were modifying the electrical system, adding a new automatic transfer switch, grading the expanded site, providing additional access to the pump station, and providing new security fencing with gates.

The Argyle & 19th Pump Station involved the addition of an engine-generator set for standby power to a 23-year old, 1.4 MGD pump station. The design included the installation of a 50 KW diesel fueled engine generator set to provide power during utility power outages. Also included were modifying the electrical system, adding a new automatic transfer switch in a person-accessible enclosure, providing a new security fence with gates for access and siting the engine-generator set and enclosure on the small site surrounded by a parking lot.

The Airport Way No. 2 Pump Station involved the remodeling of a 5-year old, 5.8 MGD pump station to replace the failed HVAC system and to add wet well gas monitoring and smoke detectors. The existing roof mounted gas fired make up air unit was replaced with an electronic furnace installed indoors. The electrical system was modified to accommodate the HVAC changes. Smoke detectors and fan failure sensors were added, the ducting was modified as required for the furnace changes, and automatic dampers were added to recirculate 75% of the dry well air to conserve energy when the pump station is unoccupied.

The Airport Way No. 3 Pump Station involved the remodel of a 5-year old, 4.0 MGD pump station to replace the heating system and to add smoke detectors, fan failure sensors and wet well hazardous gas monitoring. The design included replacing the existing gas-fired furnace with an electric unit and modifying the ducting, as required. Automatic dampers were included in the new ducting to recirculate 75% of the dry well air to conserve energy when the pump station is unoccupied.

The Swan Island Pump Station involved the addition of an engine-generator set for standby power to a 40-year old, 2.3 MGD pump station. The design included the installation of a 150 KW diesel fueled engine generator set to provide power during utility power outage. Also included were modifying the electrical system, adding a new automatic transfer switch, grading the expanded site, providing additional access to the pump station, and providing new security fencing with gates.

HVAC for Pump Stations - King County, Washington
As a subconsultant to Elcon Associates, Inc., T/WI designed the modifications to the HVAC system at the wastewater pump stations and one wastewater diversion structure. The modifications are to bring the facilities' HVAC system into compliance with the current codes and to modernize the stations.

The North Beach Pump Station involved the remodel of a 30-year old, 4.3 MGD pump station to upgrade the HVAC system to meet NFPA 820 code and replacement of the engine-generator set. The design included replacement of existing supply and exhaust fans serving both the dry well and wet well, replacement of the dry well heater and replacement of the existing 125 KW engine generator set with a 250 KW set. The new generator set will have a remote radiator in place of the existing heat exchanger and will utilize once through cooling with City of Seattle water. Automatic dampers were included in the dry well system to recirculate 75% of the air to save energy when the station is unoccupied.

The Duwamish Pump Station involved the remodel of a 29 year old 100 MGD pump station to replace obsolete and/or failed equipment and upgrade the ventilation and gas monitoring systems to conform with the latest edition of NFPA 820. Design included calculating the ventilation rates required, adding a wet well supply fan and a dry well exhaust fan and revising the existing ductwork to provide additional points of ventilation. System controls were changed from pneumatic to electrical electronic type. Wet well gas monitoring and smoke detectors were added per code.

The Dexter Avenue Regulator Station involved the remodel of the HVAC system to meet NFPA 820 code and replacement of obsolete equipment. The regulator station is an underground diversion structure with large hydraulically operated slide gates to regulate flow in different interceptors. The design replaces two ceiling mounted fans with one wall-mounted fan and modifies the duct work as necessary to accommodate the new fan.

The Carkeek Pump Station involved the remodel of a 5-year old, 8.4 MGD pump station to upgrade the ventilation system to meet the latest edition of NFPA 820. Design included calculating the ventilation rates required, adding a new wet well supply fan, modifying the dry well exhaust fan to the ductwork, eliminating two existing fans, and adding smoke detectors and gas monitoring. Also included were fan failure sensors, a wet well hazardous gas sensor and automatic dampers to recirculate 75% of the dry well air to conserve energy when the pump station is unoccupied.

Durham Advanced Wastewater Treatment Plant Solids Building HVAC and Foul Air/Odor Control - Durham, Oregon
Thomas/Wright, Inc., as a subconsultant to HDR, was responsible for the HVAC and odor control improvements to the Solids Handling Building. T/WI prepared a technical memorandum for the HVAC system in the solids handling building. The memorandum included a review of the existing system, design criteria, a summary of the exhaust air flow rates from odor producing spaces, and a preliminary design for improvements. The technical memorandum for the foul air/odor control included a summary and ranking of odor sources, a review of the existing system, and a preliminary design for a new system. Phase 2 of the project included the preparation of plans and specifications for the recommended improvements.