CITY OF PHILADELPHIA

Department of Public Health 

Environmental Protection Division 

Air Management Services 

InterOffice Memo 

To: File 

From: Biji Pandisseril 

Date: December 12, 2014 

Subject: RACT Analysis for Northeast Water Pollution Control Plant (PLID # 09513) 

Company Description: 

Northeast Water Pollution Control Plant is a water treatment plant located at 3899 Richmond Street, Philadelphia, 

PA 19137. The facility’s air emission sources include liquid treatment processes, solids treatment processes, four 

20-50 MMBTU/hr boilers, eight boilers <15 MMBTU/hr, four digester gas flares, and a cold degreaser 

Applicability for NOx and VOC RACT: 

Northeast Water Pollution Control Plant (NWPCP) is not a major source for Nitrogen Oxides (NOx) emission 

having potential NOx emissions less than 100 tons per year, the major source threshold in Philadelphia County that 

is applicable to NOx RACT for the 1997 8-hour ozone NAAQS. 

The facility is not a major source of Volatile Organic Compounds (VOC) having potential VOC emissions is greater 

than 50 tons per year, the major source threshold in Philadelphia County that is applicable to VOC RACT for the 

1997 8-hour ozone NAAQS. 

The facility is being re-evaluated for RACT under the 1997 8-hour Ozone National Ambient Air Quality Standards 

(NAAQS). 

NOx Emission Sources and NOx RACT Analysis: 

Process Descriptions – NOx Sources:

NWPCP NOx emission sources include combustion sources such as boilers, flares, and cogeneration facility. 

Below is a list of NOx sources at the NWPCP and the potential to emit (PTE). 

The combined NOx were calculated based AP-42 factors. The combined NOx potential emission is less than 68 tpy. 

Therefore the facility is not applicable to NOx RACT requirements. 

Following is the PTE calculation based on AP-42 factors: 

External Combustion Sources: Rating (MMBtu/hr) Fuel Types NOx PTE (tpy)

Bryant Steam Corp Boiler 0.580 No. 2 Oil 0.36 

Smith Boiler 0.661 Natural Gas 0.28 

HB Smith Boiler 1.139 Natural Gas 0.49 

Weil McLain Boiler (Admin Bldg) 1.632 Natural Gas 0.70 

Two (2) Cleaver Brook Boilers 14.645 each No. 2 Oil /Digester Gas 18.32 

Continental Boiler* 23.097 Digester Gas 9.92 

Kewanee Boiler* 20.085 Digester Gas/Natural Gas 8.62 

Two (2) Hurst Boiler* 20,085 each Digester Gas/Natural Gas 17.24 

Jackson & Chruch Hot Air Furnace 1.510 Natural Gas 0.65 

Broad USA Inc Absorption Chiller 0.750 Digester Gas/Natural Gas 0.24 
Flares: Capacity Fuel Types NOx PTE (tpy)

Four (4) Digester Gas Flares 45,860 SCF/hr each Digester Gas 0.27 

Cogeneration Engines Capacity Fuel Types NOx PTE (tpy

Four (4) CoGeneration Units** 1417 kWeach Digester Gas/Natural Gas 10.81 

 Facility Total NOx PTE: 68 tpy 

 * The Continental, Kewanee, and Hursts are greater than 20 MMBTU/hr but less than 50 MMBTU/hr 

 ** The facility has obtained a permit for five co-generation units but only four have been installed. 

 The permit also allowed for the installation of the Siloxane Flare which has not been installed. 

 With the addition of the fifth co-generation unit and the Siloxane Flare the PTE would not greater than 72 tpy. 

Each co-generator unit is vented through a SCR. 

VOC Sources and VOC RACT Analysis: 

NWPCP VOC emission sources include combustion sources, cold degreaser, and wastewater treatment plant 

operations. Below a list of VOC sources at the NWPCP and the potential to emit (PTE) calculation for the facility

External Combustion Sources: Rating (MMBtu/hr) Fuel Types VOC PTE (tpy)

Bryant Steam Corp Boiler 0.580 No. 2 Oil 0.05 

Smith Boiler 0.661 Natural Gas 0.02 

HB Smith Boiler 1.139 Natural Gas 0.03 

Weil McLain Boiler (Admin Bldg) 1.632 Natural Gas 0.04 

Two (2) Cleaver Brook Boilers 14.645 each No. 2 Oil /Digester Gas 2.76 

Continental Boiler* 23.097 Digester Gas 0.55 

Kewanee Boiler* 20.085 Digester Gas/Natural Gas 0.47 

Two (2) Hurst Boiler* 20,085 each Digester Gas/Natural Gas 0.94 

Jackson & Chruch Hot Air Furnace 1.510 Natural Gas 0.4 

Broad USA Inc Absorption Chiller 0.750 Digester Gas/Natural Gas 0.01 

Flares: Capacity Fuel Types VOC PTE (tpy)

Four (4) Digester Gas Flares 45,860 SCF/hr each Digester Gas 0.05 

Based of AP-42 Table 13.5-2 (8/2014 Draft) 

http://www.epa.gov/ttn/chief/ap42/ch13/final/dc13s05_8-19-14.pdf

 

Cogeneration Engines Capacity Fuel Types VOC PTE (tpy)

Four (4) CoGeneration Units** 1417 kWeach Digester Gas/Natural Gas 8.32 

 

Cold Degreaser VOC PTE (tpy)

Following is the PTE VOC calculation for the degreaser is based on using AP-42 factor, 0.33

Section, Table 4.6-2: 

VOC PTE = AP-42 emission factor x (number of unit) 

VOC PTE = (0.33 tons/year/unit) X 1 unit 

VOC PTE = 0.33 tons/year 

Wastewater treatment plant operations including pretreatment, 

The potential to emit for VOC at the NWPCP for wastewater treatment operations is estimated to be 20 tons per 

year. This number was obtained by looking at facility’s monthly VOC estimates for the last three years (July 2011- 

June 2014) and the highest monthly estimate was used and multiplied by 12, for a yearly PTE number. These 

estimates were developed using the TOXCHEM model that was tailored for wastewater facilities. The TOXCHEM 

model is an EPA-approved proprietary software package developed and distributed by Enviromega, Ltd. The model 

essentially is a sophisticated mass balance that incorporated kinetic equations to determine the fate of organic 
compound. Influent VOC concentrations and plant flows were used in the model to estimate the monthly 

concentration of VOC. 

 

 

MONTH 2014 2013 2012 2011 

 

lbs Carbon 

/month

 

lbs Carbon /month

 

lbs Carbon 

/month

 

lbs Carbon 

/month

 

 

JAN 3329 1,025 2,373 

FEB 2941 1,014 3,323 

MAR 2719 1,066 2,475 

APR 2562 1,453 2,304 

MAY 2467 1,192 3,227 

JUN 2931 1,092 2,197 

JUL 1,905 2,834 2139 

AUG 2,045 2,690 3133 

SEP 1,594 2,573 2792 

OCT 1,784 3,251 2180 

NOV 1,959 2,680 1883 

DEC 1,633 2,474 2158 

PTE VOC = (3329/2000) *12 = 20 tpy 

The total VOC PTE for the facility is less than 34 tpy. 

Conclusions and Recommendations: 

Since the potential for VOC and NOx sources are below the applicable RACT limits, the facility is not applicable to 

RACT under the 1997 8-hour ozone standard. 

1/9/15

Edward Wiener, Chief of Source Registration Date