Blackburn Wastewater Treatment Plant Upgrade Study

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Section 3.0 -Audit of Existing Facilities equipped with VFD's, and are controlled to maintain a given water level in the primary effluent channel. The biofilters are equipped with medium density Brentwmd crossflow media 6 m deep. Odours emanating from the biofilter are controlled using a cocurrent ventilation system. Aithough the biofilters are covered, some algae problems have been experienced. However, there does not appear to be fly or snail problems typically associated with trickling filters. Effluent kom the biofilters is pumped to the solids contact tank by three (2 duty; 1 standby) 60 hp Flygt pumps located in the main pumpstation. The biofilter underflow pumps are equipped with VFD's. The solids contact tank is equipped with Wyss rubber sheath diffusers manufactured by Parkson. Aeration air is supplied by two (1 duty; 1 standby) 50 hp Aerzen positive displacement blowers. Mixed liquor in the solids contact tank appears to have good sludge settling properties, with SVI's generally between 65 and 75 mL/g. Mixed liquor from the solids contact tank flow by gravity to two 29 m diameter secondary clarifiers. The clarifiers are equipped with double sided inboard emuent launders and "Tow-Bro" rapid sludge removal mechanisms manufactured by Envirex. Return biological solids (RBS) are pumped from the secondary clarifiers to the solids contact tank by thee (2 duty; 1 standby) 30 hp Flygt pumps located in the main pumpstation. 3.2.5 Emnent Disposal The plant is equipped for effluent disinfection and dechlorination using gaseous chlorine and sulphur dioxide. However, these facilities are not currently in use as the City has an exemption h m effluent chlorination. Effluent from the plant discharges to the Fraser River through a 900m diameter outfall pipe. 3.2.6 Sludge Treatment Approximately 2.5 L/s of waste secondary sludge is continuously bled off the RBS line and returned to the inlet of the primary sedimentation tanks for cothickening with the primary sludge. The waste primary and secondary sludge mixture is pumped to two mesophilic anaerobic digesters for stabilization. The two digesters are operated in series, one as a primary and the other as a secondary digester. Both digesters are equipped with floating covers. Digester heating is provided by 2 (1 duty; 1 standby) low pressure boilers. Digester gas is also used to power a 250 hp cogeneration unit manufactured by Caterpillar. The primary digester is reseeded every 2 weeks using sludge from the
Section 3.0 -Audit of Existing Facilities secondary digester. Sodium percarbonate is added to the digesters for hydrogen sulphide and odour control. The digested sludge is dewatered on belt filter presses manufactured by Envirex. Each press has a 2 rn wide gravity section, and a 1 m wide pressure section. The presses are operated for 7 h/4 4 to 5 &week. Percol757 polymer and a potato starch based product (Raifix) are used as coagulants. The presses produce a sludge cake with a dry weight solids content of approximately 22 percent. 3.3 Operations Staff The Blackburn and Lansdowne Road WWTPs are operated by a full time sta!T of eight persons consisting of one Class IV chief operator, a laboratory technician, 2 Class I1 operators, and 4 Class I operators. The operating staff are all based at the Lansdowne Road facility, where most of their duties are carried out. One operator spends 1 hld, 7 dweek to do a daily inspection at the Blackburn WWTP, and 4 hours once monthly to do the effluent composite sampling and preventive maintenance. Other City tradespeople (millwright, electrician, instrument technician) are called to the plants on an "as required" basis. 3.4 Conclusion The existing Lansdowne Road WWTP was designed for an ADWF of 44.5 Mud and a PWWF of 115 Mud. The plant is currently treating approximately 30 MU& or 67 percent of its design flow and load, and does not appear to have any unit processes in either the liquid or sludge treatment streams that are close to capacity and may serve as a "bottleneck" if flows to the plant were increased by a modest amount. The current dry weather flows and loads h m the Blackbum catchment represent less than 2 percent of the design capacity of the Lansdowne Road WWTP. The current wet weather flows (i.e. prior to implementation of the VI mitigation measures) represent less than 5 percent of the hydraulic capacity of the Lansdowne Road WWTP. Even with the expected increase in flows and loads from Blackbum sewage collection area as a result of increasing the serviced population to 5,000, these flows and loads represent less than 4 percent of the design capacity of the Lansdowne Road WWTP.
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BLACKBURN WASTEWATER TREATMENT PLAN
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Table of Contents SECTION TITLE PAG
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SECTION 1 STUDY BACKGROUND AND OBJE
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Section 1.0 -Project Background and
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Section 1.0 - Project Background an
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City of Prince George - Decision Wo
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City of Prince George - Decision Wo
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MINUTES OF MEETING PR~ECT NAME: Bla
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Blackburn WWTP Treatment Options Op
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Nores. Annual O&M cost for Blackbum
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Blackbum WWTP Treatment Options Opt
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APPENDIX A STANTEC CONSULTING LTD.
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5.0 CONCLUSIONS I '\ -. 5.1 RESULTS
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CITY OF PRINCE GEORGE Forcemain fro
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Section 6.0 -Recommended Option Key
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Section 6.0 -Recommended Option Com
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SECTION 6.0 RECOMMENDED OPTION 6.1
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SECTION 5.0 EVALUATION OF OPTIONS 5
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Section 5.0 -Evaluation of Options
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Section 5.0 - Evahation of Options
Page 57 and 58: Section 3.0 - Evaluation of Options
Page 59 and 60: SECTION 4.0 BLACKBURN TREATMENT OPT
Page 61 and 62: Section 4.0 - Blackbum Treatment Op
Page 65 and 66: Section 4.0 - Blackburn Treatment O
Page 67 and 68: Initiate llt reduction program and
Page 71 and 72: Section 4.0 - Blackbm Treatment Opt
Page 77 and 78: CITY OF PRINCE GEORGE Scale= $:I00
Page 83 and 84: :ITY Of PRINCE GEORGE Existing Chlo
Page 93 and 94: SECTION 4.0 BLACKBURN TREATMENT OPT
Page 101 and 102: Initiate Ill reduction program and
Page 105 and 106: SECTION 3.0 AUDIT OF EXISTING FACIL
Page 107: Section 3.0 -Audit of exist in^ Fac
Page 111 and 112: SECTION 2.0 III MITIGATION MEASURES
Page 113 and 114: Section 2.0 - UI Mitigation Measure
Page 115 and 116: APPENDIX E FLOW CALCULATIONS FOR SE
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Blackburn Wastewater Treatment Plant Upgrade Study

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