Proposed Air Quality Permit 6372-C-A2 - District of Columbia Water and Sewer Authority

PUBLIC NOTICE

Proposed Air Quality Permit 6372-C-A2 – District of Columbia Water and Sewer Authority (DC Water), Biosolids management facilities at the Blue Plains Advanced Wastewater Treatment Plant at 5000 Overlook Avenue SW

Notice is hereby given that, pursuant to 40 C.F.R. Part 51.161, and D.C. Official Code §2-505, the Air Quality Division (AQD) of the District Department of the Environment (DDOE), located at 1200 First Street NE, 5^th Floor, Washington, DC, intends to issue Permit #6372-C-A2 to the District of Columbia Water and Sewer Authority (DC Water) to amend and update the permit to construct (and, upon approval by DDOE, operate) Biosolids Handling Facilities previously issued on March 15, 2012.  The equipment described below is located at the Blue Plains Advanced Wastewater Treatment Plant at 5000 Overlook Avenue SW, Washington, DC. The contact person for the facility is Meena Gowda, Principal Counsel at (202) 787-2628.

Equipment to be Permitted

• Combined Heat and Power (CHP):
• Three (3) Solar Mercury 50 Combustion Gas Turbines (CT) rated at 46.3 MMBtu/hr (HHV) heat input firing digester gas (DG) or a combination of digester gas and natural gas;
• Three (3) Heat Recovery Steam Generators (HRSGs) equipped with supplemental firing by Duct Burners rated at 21 MMBtu/hr (HHV) heat input each, firing DG;
• One (1) Auxiliary Boiler (AB) rated at 62.52 MMBtu/hr (HHV) heat input, firing DG and 61.79 MMBtu/hr (HHV) heat input firing natural gas (NG); and
• One (1) Siloxane Destruction Flare (SF) rated at 6.14 MMBtu/hr heat input, firing DG
  
   
• Main Process Train (MPT):

• Two (2) Emergency Flares rated at126 MMBtu/hr heat input each, firing DG.
• One (1) Raw Sludge Blending, Screening and pre-dewatering process;
• Four (4) CAMBI  Thermal Hydrolysis Process (THP) trains;
• Four (4) 3.8 million gallon Anaerobic Digesters; and
• One (1) 44,800 scfm Bioscrubber Odor Scrubber (MPTOS).

• Final Dewatering Facility:
• Sixteen (16) Belt Filter Presses (BFP);
• One (1) 54,000 scfm Dual Stage Chemical Scrubber - Final Dewatering Facility Odor Scrubber (FDFOS); and
• One (1) new Spent Wash Water Concrete Collection Tank.
   

• Installation of Lime Storage Silos

• Installation of  two (2) new lime storage silos; 
• Installation of  Silo Particulate Control Devices; and

• Installation of Building Make-Up Air Handling Units (Space Heaters) Less than 5 MMBtu/hr Heat Input with Equivalent Combined Full Load of 33.11 MMBtu/hr limited to 94.8 MMCF/yr, firing NG

• Final Dewatering Facility (FDF): 12 units, 0.750 MMBtu/hr each, and 1 unit, 1.00 MMBtu/hr (10.00 MMBtu/hr total);
• CHP Gas Condition Facility: 2 units, 0.70 MMBtu/hr each (1.40 MMBtu/hr total) ;
• CHP Gas Blower Building: 1 unit,0.25 MMBtu/hr total heat requirement;
• CHP Turbine Plant: 3 units, 0.70 MMBtu/hr each (2.10 MMBtu/hr total);
• MPT Pre-Dewatering Building: 2 units, 3.52 MMBtu/hr each, and 1 unit, 3.17 MMBtu/hr (10.21 MMBtu/hr total);
• Digestion Building: 1 unit, 2.20 MMBtu/hr total heat requirement;
• Sludge Screening Building: 1 unit, 2.38 MMBtu/hr total heat requirement; and
• Solids Blending Building: 4 units, 1.145 MMBtu/hr each (4.58 MMBtu/hr total)

The purpose of the permit amendment is to correct items that have changed based on the final construction plans of the facilities. The changes are resulting in small potential increases in particulate matter emissions (0,38 tons per year) and carbon monoxide (CO) emissions (0.35 tons per year).  Emissions of other pollutants are to be reduced, most notably oxides of nitrogen (NOx) were there is a projected decrease in potential emissions of 7.29 tons per year and volatile organic compounds (VOC) where there is a projected decrease in potential emissions of 6.45 tons per year. As a result of the decrease in NOx, there has been no change in the non-attainment new source review (NNSR) analysis.  Other reasons for the amendment include the removal of redundant monitoring requirements and clarification of permit language.

Overall Emissions Limitations

The following emission limits are the overall emission limits for the equipment involved in the project.  In addition to these limits, some additional limits can be found in the draft permit.

The emissions shall not exceed the emission limits in the following tables as applicable:

Table 1: Total 12-Month Rolling Emission Limits from Permitted Equipment¹

Pollutant	12-Month Rolling Emissions Limit (tons/yr)
PM (Total)2	18.45
SOx	25.04
NOx	77.07
VOC	11.84
CO	97.51
PM10	18.45
PM2.5	18.45
HAPs (Total)	1.75

1. The equipment covered consists of three Solar Mercury 50 gas turbines, three duct burners, one auxiliary steam boiler, one siloxane removal system, , two emergency flares, space heating units as referenced in this permit, two odor scrubbers (MPTOS and FDFOS), and two lime silo baghouses.

2. Total PM is the sum of the filterable PM and condensable PM

Table 2- Maximum Hourly Emissions (lbs/hr)

Pollutants	Each Solar Mercury 50 Gas Turbine	Each Duct Burner	Auxiliary Boiler	Siloxane Removal System	Each Emergency Flare
PM (Total)	1.06	0.16	2.69	0.21	2.52
SOx	1.21	0.55	1.63	0.16	3.28
NOx	3.56	1.66	2.11	0.37	5.29
VOC	0.40	0.03	0.31	0.53	2.54
CO	4.34	2.31	2.22	1.25	2.52
PM10	1.06	0.16	2.69	0.21	2.52
PM2.5	1.06	0.16	2.69	0.21	2.52
Total HAPs	0.07	0.06	0.17	0.01	0.19

Table 3 – Start-Up Emissions for Two Temporary Boilers and One Emergency Flare

Pollutant	Temporary Sources During Construction
	Temporary Steam Boilers(1)(Natural Gas) (lbs/hr)	Emergency Flare (Digester Gas) (lbs/hr)
PM (Total)	0.20	2.52
SOx	0.04	3.28
NOx	2.00	5.29
VOC	0.10	2.54
CO	0.72	2.52
PM10	0.20	2.52
PM2.5	0.20	2.52

⁽¹⁾ The emission rates listed in this column are informational only and may be change without the amendment of this permit.  The boilers are permitted under separate Permit Nos. 6809 and 6810, issued to Pepco Energy Services, Inc.

The application documentation, the permit amendment request, and the draft permit and supporting documents are available for public inspection at AQD and copies may be made available between the hours of 8:15 A.M. and 4:45 P.M. Monday through Friday.  Interested parties wishing to view these documents should provide their names, addresses, telephone numbers and affiliation, if any, to Stephen S. Ours at (202) 535-1747.

Interested persons may submit written comments or may request a hearing on this subject within 30 days of publication of this notice.  The written comments must also include the person’s name, telephone number, affiliation, if any, mailing address and a statement outlining the air quality issues in dispute and any facts underscoring those air quality issues.  All relevant comments will be considered in issuing the final permit.

Comments on the proposed permit and any request for a public hearing should be addressed to:

Stephen S. Ours           
Chief, Permitting Branch - Air Quality Division

District Department of the Environment
1200 First Street NE, 5^th Floor
Washington, DC 20002

[email protected]

No written comments or hearing requests postmarked after July 28, 2014 will be accepted.

For more information, please contact Stephen S. Ours at (202) 535-1747.