Odor Control in Large Diameter Sewers

City of Columbus, Ohio Downtown Area Odor Control

City of Columbus, Ohio Downtown Area Odor Control

Project Overview Field Investigations Detailed Design

Project Overview

Project Overview Olentangy Scioto Intercepting Sewer (OSIS)

123-inch (10’-3”) circular sewer with 0.06 % slope 140-inch (11’-9”) circular sewer with 0.05% slope 123-inch X 144-inch (10’-3” x 12’-0”) rectangular sewer with 0.05%

slope 48 mgd dry weather flow

Franklin Main Sanitary Sewer 54-60-inch circular sewer 3 mgd average dry weather flow

Project Overview

Columbus Jazz and Ribfest 

First Night Columbus

Project OverviewOdor Hot Spots

Text Text Text

Field Investigations

H2S Monitoring Pressure Monitoring Fan Testing

Field Investigations

Field Investigations Fan testing and monitoring – July 28 through

August 16, 2004 Air flow rate 13,000 (north site) 17,000 cfm

(south site)

Field InvestigationsFRANKLIN MAIN

Manhole Near Federal Courthouse Positive pressure 96% (max 0.18 inches wc) Negative pressure 2% (max -0.07 inches wc) Neutral pressure 2% During fan test pressure dropped to -0.11

inches wc

Field InvestigationsFRANKLIN MAIN MANHOLE NEAR FEDERAL COURTHOUSE

Field InvestigationsFRANKLIN MAIN

Manhole in Bicentennial Park Positive pressure 44% (max 0.42 inches wc) Negative pressure 10% (max 0.04 inches wc) Neutral pressure 55% H2S averaged ~1 ppm with a max of 12 ppm During fan test pressure dropped to -0.064

inches wc and H2S dropped to 0 ppm

Field InvestigationsFRANKLIN MAIN MANHOLE IN BICENTENNIAL PARK

-0.070

-0.060

-0.050

-0.040

-0.030

-0.020

-0.010

0.000

0.010

0.020

0.030

0.040

8/9/04 0:00 8/9/04 12:00 8/10/04 0:00 8/10/0412:00

8/11/04 0:00 8/11/0412:00

8/12/04 0:00 8/12/0412:00

8/13/04 0:00 8/13/0412:00

8/14/04 0:00

Date/Time

Pres

sure

(inc

hes w

ater

)

0

2

4

6

8

10

12

14

16

18

20

H2S

Gas

(ppm

)

Pressure H2S gas Fan Test- Franklin Manhole #0178 on south end of Bicentennial Park was drawing in approximately 5,000 cfm during this test

Field InvestigationsOSIS - CHESTNUT STREET REGULATOR

Positive pressure 87% (max ~0.696 inches wc) Negative pressure 10% (min -2.302 inches wc) Neutral pressure 3% H2S averaged 7 ppm with a max of 36 ppm During fan test H2S dropped to an average of 0.3

ppm with a max of 12 ppm

Field InvestigationsOSIS - CHESTNUT STREET REGULATOR

-0 .200

-0 .100

0 .000

0 .100

0 .200

0 .300

0 .400

0 .500

8 /9 /04 12 :00 A M 8/10/04 12 :00 AM 8/11/04 12 :00 A M 8/12/04 12 :00 A M 8/13 /04 12 :00 A M 8/14 /04 12 :00 A M 8/15 /04 12 :00 A M

D ate/T im e

Pres

sure

(inc

hes w

ater

)

0

10

20

30

40

50

60

H2S

Gas

(ppm

)

C hestnut S t R egulator C hestnut S t R egulator H 2S gas N orth Fan South Fan

Fans O ff

Fan Test S tart

E nd of Fan test

Field InvestigationsOSIS - SPRING STREET REGULATOR

Positive pressure 18% (max ~0.432 inches wc) Negative pressure 56% (min -0.207 inches wc) Neutral pressure 26% H2S significantly reduced during fan testing

Field InvestigationsOSIS - SPRING STREET REGULATOR

-0.100

0.000

0.100

8/9/04 12:00A M

8/9/04 12:00PM

8/10/04 12:00A M

8/10/04 12:00PM

8/11/04 12:00AM

8/11/04 12:00PM

8/12/04 12:00AM

8/12/04 12:00PM

8/13/04 12:00AM

D ate/Time

Pres

sure

(inc

hes w

ater

)

0

10

20

30

40

50

60

H2S

Gas

(ppm

)

Spring and M arconi

C hestnut St R egulator H 2S gas

N orth Fan

South Fan

Start Fan test

Fan O ff

End Fan Test

Field InvestigationsOSIS – RICH STREET REGULATOR

H2S reduced from 8.7 ppm (average) to 0.9 ppm (average)

Neutral or negative pressure increased from 21% to 48% of time

Field InvestigationsSUMMARY

90% to 95% reduction in OSIS H2S gas concentrations OSIS depressurization is very small compared to the

reduction in H2S gas There could be a constriction in the OSIS between Long

Street and Broad Street. Performing a CCTV and Sonar inspection would provide insight into the condition of the sewer as well as the cause (if any) of the pressure fluctuations.

Catch Basin at Broad Street requires p-trap Catch basin near the Rich Street regulator requires p-trap Connecting sewers are a minor odor contribution

Field InvestigationsRECOMMENDATIONS

45,000 CFM Biofilter at former Fleet Management site

22,500 CFM Biofilter just north of downtown Install an air trap/P-trap on the catch basins at the

Broad and Rich Street regulators Install a solid manhole cover on the FM manhole

near Long Street and in Bicentennial Park Evaluate the level of debris in the OSIS and review

the potential methods to “clean” the sewer and remove contributing agents

Detailed DesignBIOFILTER COMPONENTS

Foul air duct from sewer

Blower to draw foul air

Air distribution system

Filter Irrigation System Leachate Drainage

System

Detailed DesignBIOFILTER COMPONENTS

Detailed DesignDESIGN PARAMETERS

Biofilter No. 1 – At former Fleet Management Site Airflow: 45,000 cfm Four cells @ 50 feet wide

and 45 feet long Nominal Media Depth: 78

inches Lava rock: 48-inches Large Bark Nuggets: 30-

inches Inlet air constituents Hydrogen sulfide; 20 ppmv

maximum, 5 ppmv average

Detailed DesignDESIGN PARAMETERS

Biofilter No. 2 – Near Vine St. and Neil Avenue Airflow: 22,500 cfm Two cells @ 50 feet wide and 45 feet long Nominal Media Depth: 78-inches Lava rock: 48-inches Large Bark Nuggets: 30-inches Inlet air constituents Hydrogen sulfide; 20 ppmv maximum, 5 ppmv

average

Detailed DesignFOUL AIR DUCT AND DISTRIBUTION PIPING CONSIDERATIONS

Corrosion Resistance PVC (small

diameters) Fiberglass

Reinforced Polymer Pipe (large diameters) Dampers

Detailed DesignBLOWER CONSIDERTIONS

Corrosion resistant Variable speed Vibration Noise Foul air duct connection

Detailed DesignPLENUM CONSIDERATIONS

Perforated Pipe and Stone

Detailed DesignPLENUM CONSIDERATIONS

Pre-manufactured Plastic Floor Hallsten BACTee

Detailed DesignFILTER CONSIDERATIONS

Dual Media Filters Organic and Inorganic Media Proven to produce effluent with < 0.005 ppm

H2S

Detailed DesignFILTER CONSIDERATIONS

Pilot tested inorganic media Crushed Granite (limestone degrades)

Lava Rock

Tire Chips

Detailed DesignFILTER CONSIDERATIONS

Lava Rock Advantages H2S Removal Airflow Characteristics Moisture Retension Light Weight (compared to granite)

Detailed DesignIRRIGATION SYSTEM CONSIDERATIONS

Sprinklers (with automatic controls system)

Drip tubes Must be replaced with

media Humidification chambers

Detailed DesignUNDERDRAIN SYSTEM

Leachate may be acidic Corrosion protection of underdrain trench and

piping Corrosion protection for manhole at sewer

discharge point

QUESTIONS?