SEWAGE SLUDGE INCINERATOR INFORMATIONAL MEETING

WITH THE NATIONAL ASSOCIATION OF CLEAN WATER AGENCIES

August 25, 2009 

8:30 am – 12:30 pm 

Room E301 

109 T.W. Alexander Drive 

Research Triangle Park, NC 27711 

MEETING ATTENDEES: 

U.S. EPA NACWA 

Amy Hambrick Robert Dominak 

Ketan Patel Chris Hornbeck 

Martha Smith Mark Filnert 

Charlene Spells Doug McWilliams 

Larry Elmore 

Susmita Dubey ERG

Ron Meyers Amber Allen 

Lyn Luben 

Robin Dunkins 

Rick Stevens 

SUMMARY: 

This meeting served as an information session for the benefit of both NACWA and EPA. After 

brief introductions, Bob Dominak, Residuals & Air Emissions Manager of the Northeast Ohio 

Regional Sewer District gave a presentation on sewage sludge incineration. This comprised the 

bulk of the meeting and was followed by a brief period of open discussion before the meeting was 

adjourned. The meeting agenda and presentation are attached. 

SSI PRESENTATION OVERVIEW: 

Mr. Dominak began by presenting a comprehensive history on biosolids (sewage sludge) 

management and the eventual development of waste water treatment plants (WWTPs). He 

described the different factors that can contribute to the composition of sewage sludge, which in 

turn affect emissions resulting from the incineration of the sewage sludge. The main factor is the 

influent itself, but primary waste conditioning methods, dewatering devices, and plant operations 

also make a difference. 

Mr. Dominak then reviewed the current biosolids management practices in use in the U.S. He 

emphasized that choosing what management method is best suited for a particularly treatment 

plant is a local decision; what works well for one municipality might not be economical or 

technologically feasible for another. Other attendees representing NACWA agreed and provided 

examples of such scenarios with which they had experience. 

After a detailed discussion of the technical aspects of SSIs, control methods, and energy recovery 

techniques, Mr. Dominak explained the current regulations in effect for these incinerators. He 

then explained SSI emissions in the context of the 10 Section 129 pollutants. PM, PM2.5, opacity, 

and mercury already have national regulatory emission limits for SSIs, and therefore there are test 

data available in many cases for these pollutants. On the other hand, SO2, HCl, NOx, CO, lead, 
cadmium, and dioxins do not have national regulatory emission limits for SSIs, so less test data 

exists for these pollutants. EPA and NACWA both conducted dioxin surveys in the mid 1990’s, 

however, obtaining dioxin emission data for 14 SSIs. 

Finally, Mr. Dominak illustrated the potential impacts of MACT standards for these pollutants for 

SSIs, both on the industry and on the environment. 

DISCUSSION: 

After Mr. Dominak’s presentation, the floor was opened for discussion. 

Of primary concern was the idea of having static limits set for the pollutants for all SSIs, 

even though emissions from SSIs are highly dependent on local conditions. Repeated 

emphasis was placed on the fact that no matter what, a publicly owned treatment works 

(POTW) must treat whatever is received. The plant has limited control over the 

composition of the influent, as this depends on the percent of residential verses industrial 

entities served by the plant. In addition, illegal dischargers, mercury from dental 

amalgams, runoff from highways, and other factors over which a plant has no control will 

contribute to high variability in emissions for a plant. Instead of a static limit for 

pollutants, it was suggested that standards for control efficiencies might be more 

appropriate, since this is something a plant could more easily control. If a limit must be 

determined, it was recommended that there be separate categories based on incinerator 

type (e.g. multiple hearth vs. fluidized bed). It was thought the facilities should also be 

categorized by size or by the types of influent sources (residential vs. industrial). 

ATTACHMENT:

Incineration of Biosolids (Sewage Sludge) Presentation by Robert P. Dominak 
Incineration of 

Biosolids (Sewage Sludge)

Robert P. Dominak 

Residuals & Air Emissions Manager

Northeast Ohio Regional Sewer District

August 25, 2009
Presentation Overview

• History of Biosolids (sewage sludge) 

Management 

• Incineration of Biosolids 

• Air Pollution Control Devices

• Energy Recovery Methods

• Current Incineration Regulations
Presentation Overview

• Air Emissions of the 10 Pollutants Regulated 

under Section 129 from biosolids incinerators

• Possible Impact of Potential MACT Standards 

on POTWs that practice incineration

• Environmental Impact of MACT Standards

• Summary & Action Items
Public Perception of Biosolids

Mr. Dominak –

Why don’t you just stop 

manufacturing that stuff 

at your plants?

Ma’am did you...?

Oh! It’s from me?

Yes! God gave us...
History of Biosolids Management

Deuteronomy 23:12-13

You shall have a place outside the 

camp...where you shall dig a hole...

and cover up your Biosolids.

Moses

Who was the first Biosolids Manager?
History of Biosolids Management

• 2100 BC: Egypt

- Waste from Elite 

& Religious sent 

to rivers

• 1600 BC: Crete

- Toilets and Sewer 

System for Royalty

• 300 BC: Athens 

- Waste hauled to landfill

Charged landowners 
History of Biosolids Management

• 300 BC to 400 AD: Rome

- Public Toilets - Waste to Rivers

Fall of Rome

• 500 to 1700s: 

- Open trenches

- Chamber pots

- Outhouses

- Cesspools
History of Biosolids Management

• Late 18th Century

- Sewers 

•1860s: Septic Tanks

•1900s: Wastewater Treatment Plants

Cleveland Easterly - 1908 

Cleveland Westerly - 1914

Cleveland Southerly - 1927
One of the first Biological WWTPs 

in the U.S.

Easterly Wastewater Treatment Plant

1938
History of Biosolids Management

Biosolids Management 1930s + 

• Landfilling

• Incineration

• Land application

• Give it away to residents
Cuyahoga River Fire

June 22, 1969
June 2, 1949

March 14, 1951

Nov 3, 1952

Dec 19, 1961

Cuyahoga River Fires

Nov 4, 1952

Cleveland State 

University Archives
Federal Water Pollution Control 

Amendments of 1972

October 18, 1972

Gives EPA the authority to implement pollution control 

programs such as wastewater treatment standards 

- Secondary Treatment

- Construction Grants up to 75% of Costs for POTWs including 

SSIs + 15% additional funding for Innovative & Alternative 

Technologies
U.S. EPA’s Biosolids Regulations

February 19, 1993

• 40 CFR Part 503

Standards for the Use or Disposal of Biosolids

- Establishes pollutant limits, management practices, 

and operational standards for Biosolids that are:

a. applied to the land, 

b. placed on a surface disposal site, or 

c. fired in an incinerator. 

- Landfilling covered under 40 CFR Part 258
16,500 Publicly Owned 

Treatment Works (POTWs) 

in the United States
Southerly WWTC - 240 acres
Southerly WWTC Process Flow Diagram
Differences in Composition & 

Quality of Biosolids
Difference in Biosolids Due to:

1. Plant Influent 

- % Residential

- % Commercial Businesses

- % Industrial (cadmium, lead, mercury)

- Industrial Pre-Treatment Programs?

- Groundwater contaminants - Infiltration/inflow
Difference in Biosolids Due to:

1. Plant Influent (cont’d) 

- Sanitary & Combined Sewer Systems

- Illegal discharges or dumps down sewers

- Illegal sewer tie-ins

- Mercury from dental amalgams
Difference in Biosolids Due to:

1. Plant Influent (cont’d) 

- Runoff from highways

- Can’t store influent - need to treat when received

- Can’t choose or reject what is coming in

on a real time basis
Difference in Biosolids Due to:

2. Conditioning of primary and waste 

activated solids to improve dewatering

- chemicals 

- alum

- ferric 

- lime

- polymer 

- thermal 
Difference in Biosolids Due to:

3. Dewatering Devices

- vacuum filters 

- plate & frame presses

- belt filter presses

- centrifuges

- screw and rotary presses
Difference in Biosolids Due to:

4. Plant Operations 

- activated sludge process

- trickling filter process

- physical chemical process 

- single or two stages of treatment

- nitrification / de-nitrification process
Difference in Biosolids Due to:

4. Plant Operations (cont’d) 

- ratio of primary solids and 

waste activated solids (sludge)

- solids removal efficiency

- bio-nutrient removal requirements

- recycle flows from unit treatment processes 
Improvements in the 

Quality of Biosolids
Improvements in the 

Quality of Biosolids

Substantial reduction in heavy metals in the 

influent, effluent and biosolids due to:

1. 40 CFR Part 403 – General Pretreatment 

Regulations for Existing & New Sources 

of Pollution

2. 40 CFR Part 503 – Use or Disposal of 

Sewage Sludge
Reduction in Metal Concentrations

City of LA Hyperion WWTP
Average Reductions from 1980 - 2004 at the 

NEORSD’s three WWTPs:

Zinc 87 90

Nickel 89 90

Lead 95 100

Copper 62 90

Chromium 90 97

Cadmium 99 99

% Reduction 

in Effluent

% Reduction in 

Metal Influent

Reduction in Metal Concentrations
Reduction in Metal Concentrations

Southerly WWTC Biosolids - Cadmium

0

200

400

600

800

1000

1200

1980198119821983198419851986198719881989199019911992199319941995199619971998199920002001200220032004

Year

C

o

n

c

e

n

tr

a

ti

o

n, d

r

y

m

g

/kg

AVG

PEAK

NEORSD Pretreatment Program

1 Illegal discharger

1 Illegal discharger
Current Biosolids 

Management Practices 

in the United States
Alkaline Stabilization

Lime added to 

Biosolids

Final Product - soil amendment or agricultural lime
Composting

Organic Matter is decomposed

Final Product - landscaping and 

agricultural purposes
Heat Drying

• Water evaporated

• 50 - 65 % reduction 

in volume

Final Product - Organic Fertilizer (pellets)
Incineration

• Water evaporated

• Combustion of 

volatile content

• 85 - 95% 

reduction in 

volume

Final Product - Ash
Incineration of Biosolids (typ.)

Water 75%

Dry solids 25%

Volatile (burnable) Content

70% 

Inert Ash Content

30% 

100 pounds of Biosolids

75 lbs 25 lbs

17.5 lbs 7.5 lbs

92.5% Reduction in Volume
Biosolids applied to: 

- Farm Land 

- Reclamation Sites 

Land Application

Low Cost Fertilizer
Biosolids applied to dedicated disposal sites 

Surface Disposal

– Limited number of crops 

grown

– Higher application rates 

than allowed at farms

– Access to site restricted

Low Cost Fertilizer
Disposal of biosolids at :

1. Commercially-owned landfills

2. Municipality/District owned landfill

Landfilling
Distributed & 

Marketed 

9%

Landfilled

28%

Incinerated

17% 

Land Applied

45%

Surface 

Disposal 

1%

Biosolids Management Practices 

in the United States (Est.)

(5 - 7 million dry metric tons/year)

(850,000 - 1.2 million)
Local Decision Driven By Local 

Factors & Fears (NIMBYs)

Selection of a Biosolids 

Management Option

is a
NEORSD 

Long-Term Residuals 

Management Plan

A Unique Case Study 
• Political subdivision of the State of Ohio (1972)

• Provide wastewater treatment services 

for Cleveland and 60 suburbs

- 1.1 Million residents and businesses

• Process an average of 230 million gallons 

of wastewater per day

• 1972 - 2008: invested over $2.2 billion in projects 

to protect public health & the environment 

• Will invest $8 billion over the next 25 - 30 years

(Plants, CSOs, SSOs, Stormwater)
Southerly

(100 MGD)

Easterly

(100 MGD)

Westerly

(30 MGD)

NEORSD Wastewater Treatment Plants

Biosolids 

Force Main
Five Wastewater Residuals

• Grit 

• Screenings 

• Skimmings

• Biosolids 

• Biosolids

Incinerator Ash 
NEORSD Residuals 

Management Practices

• Grit & Screenings - 100% Landfilled 

• Biosolids - 90% Incinerated / 10% Landfilled

• Biosolids Incinerator Ash - 100% Landfilled

• Skimmings - 100% Incinerated

Full compliance with all applicable 

Rules and Regulations
FACED WITH:

• Potential Regulatory Changes 

(Biosolids, Air Emissions, Landfilling)

+

• Potential Increases in 

Residuals Disposal Costs

Conduct a Residuals Management Study
NEORSD Biosolids 

Management Plan

January 2005
Southerly Biosolids

Replace 4 existing Multiple 

Hearth Incinerators 

(Built in 1964 with major 

upgrades in the 1970s)

with 3 new Fluidized 

Bed Incinerators

Landfilling as a back-up
Southerly Biosolids

• Decommission the existing 

Sludge Thermal Conditioning

(Zimpro) System 

(Mom & Grandma’s old pressure cooker)

• Install a new chemical conditioning system 

and 9-new high solids dewatering centrifuges
Easterly Biosolids

Continue to pump biosolids 

from 

Easterly to Southerly 

Southerly

Easterly

Biosolids 

Force Main
Westerly Biosolids

• Continue to operate the 2 existing MHs

- Totally renovated in mid 1990s

- In compliance with all permit limits

- Make minor renovations on an “as needed” basis

- Landfilling as a back-up
Southerly Biosolids 

Handling & Incineration Facility

Incineration

Dewatering

Truck Loading
Changes at the NEORSD

(2007 – 2008)
Changes at the District 

• New Senior Staff Members

• New Board of Trustees Members

• Major Rate Increases required to fund 

improvements to Collection Systems and 

Plants

Question - Should the District continue with 

the Design and Construction of

Southerly’s Biosolids Handling and 

Incineration Project?
Retain a Workgroup of Independent 

Biosolids Management Experts to:

---------------------------------------------------------------

- Review the Fluidized Bed Incineration 

recommendation 

- Investigate newer biosolids management 

technology 

- Determine the carbon footprint of the various 

biosolids management options 

- Determine if incineration is still the most 

viable and cost-effective option for Southerly
Validation Workshop 

August 11 - 15, 2008

Harder Schafer Welp Logan Lue-Hing Stone Shea
Validation Workgroup’s Findings

The Proposed Incineration project:

- Is the most cost-effective option

- Will significantly reduce regulated air 

emissions and greenhouse gas emissions 

- Has the lowest odor, noise, traffic impacts

Landfill: 180 - 330 truck loads per week
Workgroup’s Recommendations

• Proceed with the proposed Fluidized Bed Incineration 

Project 

• Consider Green energy production

- Boilers supplying steam to a steam-powered turbine 

generator to produce electricity

• Accelerate construction of the new 

Fluidized Bed Incinerators

(Cost Savings ~$7,200/day or $2.6 million/year)

Fluidized Bed Incineration with green energy 

production is Southerly’s most viable, costeffective, and environmentally friendly biosolids 

management option.
Southerly Renewable 

Energy Project

Steam Turbine 

Generator Bldg.

N

Sept. 2008
Southerly Renewable 

Energy Project

• Obtain Permits - Oct. 2008

• Awarded a Fluidized Bed 

Incinerator Equipment 

Procurement Contract - Nov. 2008

• Start Construction - 4th Q 2009

• Complete Project - 4th Q 2012

Total Project Cost = $170 million

More information to follow
Incineration of Biosolids
Incineration of Biosolids

231 Incinerators @ 124 POTWs 

in 25 states + Puerto Rico

• 167 Multiple Hearths

• 63 Fluidized Beds

• 1 Electric Arc

Cincinnati Mill 

Creek WWTP

6 MHs 3 FBs
Multiple Hearth Incinerator
Fluidized Bed Incinerator
Electric Arc Incinerator
Why POTWs Incinerate?

- A 85 - 95% reduction in solids, resulting in 

a non-hazardous, non-toxic, inert ash

- Destruction of pathogens

- Degradation of potentially toxic organic compounds

- Most cost-effective biosolids management option

- Don’t have access to land application sites 

or landfills 
Why POTWs incinerate?

- Can’t land apply during winter months

- Don’t have the unit processes required to produce 

compost or a land applicable product

- Substantially reduced truck traffic

- Low air and odor emissions
Why POTWs incinerate?

- Limited hours of operations at landfills and land 

application sites - additional on-site storage required

- Already have a significant capital investment 

in incineration 

- Greater control over biosolids management costs. 

No need to worry about increases in landfilling 

costs, transportation costs and land application 

costs.
Southerly Biosolids Management 

Unit Costs (2008 Est.) 

Multiple Hearth Incinerators burning thermally 

conditioned, centrifuge dewatered biosolids

$63

Landfilling

($/wet ton)

$25 $80 O&M Costs

Land App. 

($/wet ton)

Incineration

($/wet ton)

Westerly WWTP Incineration O&M Costs 

= $42/wet ton
Southerly Biosolids Management 

Unit Costs (2014 Est.)

$93

$86

Landfilling

($/wet ton)

$46 $100

Total Costs 

O&M + amortized 

capital costs

$31 $80 O&M Costs

Land App. 

($/wet ton)

Incineration

($/wet ton)

Incineration is Southerly’s most Cost Effective 

Biosolids Management Option
Why Isn’t Land Application 

Cost Effective for Southerly?

• Need to construct a sludge

stabilization process 

(digestion, lime add., etc.)

• Need to construct

Biosolids Storage Facilities

(140 days)

• Long Distances to Land Application Sites
• Fluidized Beds in lieu of Landfilling

180 trucks/week x 52 weeks/year x 130 miles

= 1.2 million vehicle miles/year

(~245,000 gal of fuel oil/year)

• Fluidized Beds in lieu of Land Application

240 trucks/week x 52 weeks/year x 150 miles

= 1.9 million vehicle miles/year (min.)

(~380,000 gal of fuel oil/year)

Reduced Truck Traffic

Southerly WWTC
Low Emissions

Estimated Southerly 2014 Air Emissions (Tons)

Totals 60 56 84

Lead (Pb) 0 0 0

1 3 4

Organic 

Compounds (OC)

6 1 2

Particulate

Matter (PM)

6 4 6

Sulfur

Dioxide (SO2)

44 44 65

Nitrogen 

Oxides (NOx)

3 4 6

Carbon 

Monoxide (CO)

Trucks 

to Land

App. Sites

Trucks 

to

Landfill

Three 

Fluidized Bed

Incinerators

Pollutant
Air Pollution Control Devices 
Air Pollution Control Devices 

• Venturi (196) / Impingement Tray Scrubbers(~200)

• Advanced Venturi Scrubbers (~ 31)

- Venturi Pak or Ring Jet
Air Pollution Control Devices 

• Wet Electrostatic Precipitators (~ 29)

• Afterburners - internal and external (~ 78)

• Activated Carbon Injection for Hg control (3) 
Air Pollution Control Devices 

•Bag House (3)

• Activate Carbon Adsorption (1)

• Chemical Injection for NOx Control (3)
Energy Recovery Methods 
Energy Recovery Methods 

• Center Shaft Air Recirculation

• Recuperator (primary heat exchanger)

• Heat Exchanger

• Regenerative Thermal Oxidizer

• Boiler

• Steam Turbine Generator
Energy Recovery Methods 

• The use of the various energy recovery 

methods is based on the need to further reduce 

emissions and local economic conditions:

- Consent Decrees

- Meeting more stringent emission standards

- Life Cycle Costs

- Cost & Source of Energy

- coal, natural gas, nuclear, hydro, oil, etc.

- Cost-Effectiveness 

- $ per ton of pollutant removed
Exhaust Gas Systems 
Exhaust Gas Systems 
Exhaust Gas Systems 
Exhaust Gas Systems 
Exhaust Gas Systems 
Exhaust Gas Systems 
Exhaust Gas Systems 
Benefits of Energy Recovery at the 

NEORSD Southerly WWTC - MHs

(site-specific)
• 1973 - Decision made to install a new a 

new Sludge Thermal Conditioning (Zimpro) 

System at Southerly

(pressure cooker)

• Thermal Conditioning (Zimpro) 

+ Vacuum Filters 

= Cake @ 40 - 45% solids

• Polymer + Vacuum Filers 

= Cake @ 17 - 21% solids 

Benefits of Energy Recovery at the 

Southerly WWTC - MHs
• Zimpro requires large 

quantities of high 

pressure steam - $$$

• Convert heat in the incinerator exhaust 

gases to high pressure steam using 

boilers

Benefits of Energy Recovery at the 

Southerly WWTC - MHs
Operation of Waste Heat Boilers (1982 – 2007)

- Steam Production = 2.5 billion pounds 

- Natural Gas Saved = 3.1 billion cubic feet 

- Natural Gas Cost Savings = $14 million

Benefits of Energy Recovery at the 

Southerly WWTC - MHs
Reduction in Carbon Footprint (1982 – 2007)

(equivalent metric tons of CO2)

- CO2 = 191,000 tons x 1 = 191,000 metric tons

- CH4 = 3.2 tons x 21 = 70 metric tons 

- N2O = 3.0 tons x 310 = 930 metric tons 

----------------------------------------------------------------------

Total Reduction = 192,000 metric tons

Annual Reduction = 8,000 metric tons/yr

Benefits of Energy Recovery at the 

Southerly WWTC- MHs
Four Multiple 

Hearth Incinerators

Three Fluidized 

Bed Incinerators

Benefits of Energy Recovery at the 

NEORSD Southerly WWTC - FBs

(site-specific)
Decommission Southerly’s Biosolids 

Thermal Conditioning (Zimpro) System

- Reduction in Natural Gas Usage 

~ 100 million CF/yr (Vapor Combustion Units)

~ 150 million CF/yr (Process Steam)

~ 250 million CF/yr ($3.25 million/yr)

- Reduction in Electrical Usage 

~ 5 Million kWh/year ($350,000/yr)

Benefits of Energy Recovery at the 

NEORSD Southerly WWTC - FBs
Energy Savings

Reuse of energy in incinerator exhaust gases

70°F

900°F -

1250°F

1500°F

100°F

300°F

Savings: ~80 Million CF Nat. Gas/yr = ~$1 Million/year

1000°F

650°F
Fluidized Bed Incineration with 

Energy Recovery
Steam Turbine Generator

- Produce 2.6 - 3.6 MW of electricity 

Southerly’s Current & Future usage ~ 13 MW

- Use the electricity in the new 

Renewable Energy Facility
Carbon Footprint Analyses

Annual GHG emissions from biosolids 

processing operation calculated using:

a. Climate Registry General Reporting 

Protocol and 

b. Intergovernmental Panel on Climate 

Change (IPCC) Inventory Methodologies
Carbon Footprint Analyses - Southerly WWTC

(Direct + Electric Power)

* Includes reduced emissions from purchased power 

(i.e., reduced Power Plant Emissions).

Landfilling 25,000

(transport fuel + decay)

Multiple Hearth Incineration 11,500

Fluidized Bed Incineration with 5,700

out energy recovery

- 10,500*

Fluidized Bed Incineration with 

Energy Recovery & Steam 

Turbine Generator

GHG Emissions

(Metric Tons CO2)/yr

Biosolids 

Process
Current Incinerator Regulations
Current Incinerator Regulations

40 CFR Part 503 

Use or Disposal of Sewage Sludge

• Site specific emission limits:

- Arsenic

- Cadmium

- Chromium

- Lead

- Nickel

Risk Based – Protective of Public Health

(HEI - 70-years of continuous exposure)
Current Incinerator Regulations

40 CFR Part 503 (Cont’d)

• Demonstrate compliance with NESHAP for:

- Beryllium: 10 grams/24-hours

- Mercury: 3,200 grams/24-hours

• Total Hydrocarbon (THC) 

- surrogate for emissions of potentially toxic organic 

compounds

100 ppm, as propane, corrected to 7% oxygen & 0% 

moisture on a monthly average basis - Technology Based 

- Carbon Monoxide monitoring as an alternative

• Part 503 Regulation’s Risk Assessment Report
Current Incinerator Regulations

40 CFR Part 60, Subpart O: 

Standards of Performance Standards for 

Sewage Treatment Plants 

Impacts SSIs that were built after June 13, 1972

- Monitoring of sludge feed 

- Site specific air pollution control equipment pressure 

drops limits

- Compliance with a PM emission limit of 1.3 lbs/dry ton 

incinerated (99.9% removal)

- Site specific oxygen in incinerator exhaust gases 

concentration limits

- Others
Current Incinerator Regulations

Clean Air Act Amendments of 1990

• Title V

• Synthetic Minor (FESOP)

• Non-Title V (Natural Minor)

• 112(k)
Current Incinerator Regulations

Limited State and Local Regulations

• CO limit of 100 ppm 

• Afterburning

• Limited Hours of Operation

• Continuous Monitoring of Exhaust Gases 

- e.g., NOx, Opacity, CO, SO2

• Lower Emission Limits

• Minimum Temperature & Resident time 

• Best Available Technology

• NOx RACT 
Current Incinerator Regulations

Part 503 - Southerly WWTC

Biosolids Concentrations (mg/dry kg)

* Monthly Basis ** Maximum month 

Nickel 379,429 83

Lead 12,508 132

Chromium 18,071 191

Cadmium 272 16

Arsenic 1,290 16

Actual 2008 

Concentrations**

Risk Based 

Pollutant Limit*
Current Incinerator Regulations

Part 503 - Westerly WWTC

Biosolids Concentrations (mg/dry kg)

* Bi-Monthly Basis ** Maximum 2 month period 

Nickel 168,995 53

Lead 2,678 240

Chromium 50,473 553

Cadmium 450 18

Arsenic 511 18

Actual 2008 

Concentrations**

Risk Based 

Pollutant Limit*
Current Incinerator Regulations

Part 503 - Southerly WWTC

Air Emissions

39

( > 10 normal )

THC 100

(ppm, monthly average)*

Mercury (g/24-hrs) 3,200 80

Beryllium (g/24-hrs) 10 0.07

Actual 2008 

Emissions

Risk Based 

Limit**

Pollutant
Current Incinerator Regulations

Part 503 - Westerly WWTP

Air Emissions

THC 100 7

(ppm, monthly average)*

Mercury (g/24-hrs) 3,200 12

Beryllium (g/24-hrs) 10 < 0.04

Actual 2008 

Emissions

Risk Based 

Limit**

Pollutant
Emissions of the 10 Pollutants 

Regulated under Section 129 from 

Biosolids Incinerators
Factors Impacting Emissions

Emissions will vary from incinerator to incinerator 

due to the:

1. Metal concentrations and control efficiencies

2. Air pollution control equipment

3. Use of afterburners

4. Feed Rates

5. % solids

6. % volatile solids
Factors Impacting Emissions

7. Carbon, Hydrogen, Nitrogen, Oxygen and 

Sulfur concentrations in feed 

8. BTU content 

9. Quantity & type of aux. fuel

10. Excess Oxygen

11. Exhaust gas and freeboard temperatures
Factors Impacting Emissions

12. Need to comply with more stringent 

site-specific regulations

13. Efficiency of the scrubbing system

14. Reported emissions can also vary from site to 

site due to the use of different test methods

Test results from different 

POTWs are not always an 

apples-to-apples comparison
Particulate Matter

(PM & PM2.5)
Particulate Matter

(PM & PM2.5)

National Regulatory Limit:

NSPS = 1.3 lbs/dry ton PM for SSIs 

constructed after June 13, 1972

PM and PM2.5 emissions are a function of the:

- air pollution control trains

- pressure drop across the scrubbing system

- exhaust gas temperatures

- use of an afterburning zone, etc. 
Particulate Matter 

AP-42

Multiple Hearths Fluidized Bed (E rating)
PM2.5 (AP-42)

No certified test methods for PM2.5
Particulate Matter 

Southerly WWTC (June 9 - 12, 1993)

0.64 0.42 0.43 0.50

PM 

(lbs/dry ton)

2 2.1 1.8 2

Feed Rates 

(tons/hr)

1.28 0.88 0.77 0.99

PM 

(lbs/hr)

No. 1 No. 2 No. 3 No. 4

4 Identical MHs with internal afterburners & 

venturi / impingement tray scrubbers
Particulate Matter 

Southerly WWTC

SoutherlyWWTC - PM Emission Rates

(1993 - 2007)

0

0.2

0.4

0.6

0.8

1

1 2 3 4567 8 9 10 11 12 13 14 15 16

lbs/d

ry

ton

4 Identical MHs with internal afterburners & 

venturi / impingement tray scrubbers
Particulate Matter 

Southerly WWTC

3 0.65 9-3-04

2 0.43 10-23-03

2 0.40 12-18-07

3 0.88 12-18-01

4 0.55 12-18-01

2 0.91 11-18-03

3 0.86 4-2-03

1 0.45 5-24-01

4 0.71 11-13-01

Incinerator No. Lbs/dry ton Date
Particulate Matter 

Southerly WWTC

3 0.65 7-27-07

4 0.51 9-11-02

2 0.53 9-10-02

1 0.26 9-9-02

Incinerator No. Lbs/dry ton Date
Particulate Matter 

Newest FBs

• Cincinnati Little Miami (venturi/impingement tray)

= 0.11 lbs/dry ton

• Ypsilanti (advanced venturi + wet ESP)

= 0.047 lbs/dry ton

• St. Paul Metro (bag house, advanced venturi, wet ESP)

= 0.013 lbs/dry ton

• St. Paul Metro PM10 = 0.16 lbs/dry ton (range 0.0093 – 0.98) 

(filterable + condensable)

No increases in PM or PM10 without the bag house and the 

wet ESP in service - Requesting change in permit!
Opacity

(as applicable)
Opacity 

(as applicable)

National Regulatory Limit:

20% on a six-minute average
Sulfur Dioxide 

(SO2)
Sulfur Dioxide

No National Regulatory Limits

SO2 emissions are a function of the:

- sulfur content of the biosolids,

- quantity and type of auxiliary fuel used
Sulfur Dioxide

Southerly WWTC (June 9 - 12, 1993)

3.7 1.2 0.36 1.3

SO2

(lbs/dry ton)

2 2.1 1.8 2

Feed Rates 

(tons/hr)

7.47 2.6 0.65 2.5

SO2

(lbs/hr)

No. 1 No. 2 No. 3 No. 4

4 Identical MHs with internal afterburners & 

venturi / impingement tray scrubbers
Sulfur Dioxide 

Southerly WWTC

SoutherlyWWTP - SO2 Emission Rates 

(1993 & 2002)

0

0.5

1

1.5

2

2.5

3

3.5

4

1 2 3 4 5 6 7

lbs/d

ry

ton

4 Identical MHs with internal afterburners & 

venturi / impingement tray scrubbers
Sulfur Dioxide 

Southerly WWTC

4 0.26 9-11-02

2 0.98 9-10-02

1 0.26 9-9-02

Incinerator No. Lbs/dry ton Date
Sulfur Dioxide

Newest FBs

• Cincinnati Little Miami (venturi/impingement tray)

= 0.11 lbs/dry ton

• Ypsilanti (advanced venturi + wet ESP)

= Didn’t test

• St. Paul Metro (bag house, advanced venturi, wet ESP)

= Didn’t test
Hydrogen Chloride 

(HCl)
Hydrogen Chloride

No National Regulatory Limits

HCl emissions are a function of the 

chloride content of the biosolids
Hydrogen Chloride 

Southerly WWTC (June 9 - 12, 1993)

0.027 0.008 0.007 0.003

HCl

(lbs/dry ton)

2 2.1 1.8 2

Feed Rates 

(tons/hr)

0.055 0.017 0.0132 0.007

HCl 

(lbs/hr)

No. 1 No. 2 No. 3 No. 4

4 Identical MHs with internal afterburners & 

venturi / impingement tray scrubbers
Hydrogen Chloride 

Southerly WWTC (June 9 - 12, 1993)

4 Identical MHs with internal afterburners & 

venturi / impingement tray scrubbers

SoutherlyWWTC - HCl Emission Rates

1993

0

0.005

0.01

0.015

0.02

0.025

0.03

1 2 3 4

lb

s/

d

r

y

ton
Hydrogen Chloride

Newest FBs

• Cincinnati Little Miami (venturi/impingement tray)

= Didn’t test 

• Ypsilanti (advanced venturi + wet ESP)

= 0.007 lbs/dry ton

• St. Paul Metro (bag house, advanced venturi, wet ESP)

= 0.006 lbs/dry ton
Oxides of Nitrogen 

(NOx)
Oxides of Nitrogen

No National Regulatory Limits

NOx emissions are a function of the:

- nitrogen content of the sludge 

- amount of auxiliary fuel utilized

- % solids of the feed 

- localized temperature within the 

burning zone.
Oxides of Nitrogen 

Southerly WWTC (June 9 - 12, 1993)

10.1 7.8 5.7 7.6

NOx

(lbs/dry ton)

2 2.1 1.8 2

Feed Rates 

(tons/hr)

20.2 16.4 10.2 15.1

NOx 

(lbs/hr)

No. 1 No. 2 No. 3 No. 4

4 Identical MHs with internal afterburners & 

venturi / impingement tray scrubbers
Oxides of Nitrogen 

Southerly WWTC

SoutherlyWWTC - NOx Emission Rates 

(1993 - 2004)

0

2

4

6

8

10

12

1 2 3 4 5 6 7 8

lb

s/

d

ry

ton

4 Identical MHs with internal afterburners & 

venturi / impingement tray scrubbers
Oxides of Nitrogen 

Southerly WWTC

3 7.15 7-27-04

4 4.54 9-11-02

2 9.62 9-10-02

1 3.37 9-9-02

Incinerator No. Lbs/dry ton Date
Oxides of Nitrogen

Newest FBs

• Cincinnati Little Miami (venturi/impingement tray)

= 0.85 lbs/dry ton 

• Ypsilanti (advanced venturi + wet ESP)

= Didn’t test

• St. Paul Metro (bag house, advanced venturi, wet ESP)

= Didn’t test
Oxides of Nitrogen

WERF Study

• NOx emissions from multiple hearth 

incinerators located in St. Louis, Cincinnati, 

Indianapolis varied from 2 - 20 lbs/dry ton

• NOx and CO emissions are 

inversely proportional

NOx CO
Carbon Monoxide 

(CO)
Carbon Monoxide 

No National Regulatory Limits

CO emissions are a function of the 

temperature, resident time and oxygen in 

incinerator
Carbon Monoxide 

Southerly WWTC (June 9 - 12, 1993)

0.12 0.20 0.73 0.02

CO

(lbs/dry ton)

2 2.1 1.8 2

Feed Rates 

(tons/hr)

0.23 0.43 1.32 0.035

CO

(lbs/hr)

No. 1 No. 2 No. 3 No. 4

4 Identical MHs with internal afterburners & 

venturi / impingement tray scrubbers
Carbon Monoxide 

Southerly WWTC 

4 Identical MHs with internal afterburners & 

venturi / impingement tray scrubbers

SoutherlyWWTP - CO Emission Rates

(1993 - 2009)

0

0.5

1

1.5

2

2.5

3

1 2 3 4 5 6 7 8

lbs/d

ry

ton
Carbon Monoxide 

Southerly WWTC

3 0.95 7-27-09

4 2.75 9-11-02

2 0.105 9-10-02

1 0.051 9-9-02

Incinerator No. Lbs/dry ton Date
Carbon Monoxide

Newest FBs

• Cincinnati Little Miami (venturi/impingement tray)

= 0.046 lbs/dry ton 

• Ypsilanti (advanced venturi + wet ESP)

= 0.88 lbs/dry ton

• St. Paul Metro (bag house, advanced venturi, wet ESP)

= Didn’t test
Lead 

(Pb)
Lead 

No National Regulatory Limit 

Pb emissions are a function of the:

- concentration of lead in feed, 

- burning zone temperatures, and

- the control efficiency of the air pollution 

control train.
Lead

Southerly WWTC (June 9 - 12, 1993)

0.068 0.002 0.0006 0.001

Pb

(lbs/dry ton)

2 2.1 1.8 2

Feed Rates 

(tons/hr)

0.136 0.005 0.001 0.003

Pb

(lbs/hr)

No. 1 No. 2 No. 3 No. 4

4 Identical MHs with internal afterburners & 

venturi / impingement tray scrubbers
Lead

Southerly WWTC

4 Identical MHs with internal afterburners & 

venturi / impingement tray scrubbers

SoutherlyWWTC - Lead Emission Rates 

(1993 - 2009)

0.0001

0.001

0.01

0.1

1

1 2 3 4 5 6 7 8

lb

s/d

ry

ton
Lead

Southerly WWTC

3 0.0083 7-27-09

4 0.0032 9-11-02

2 0.0025 9-10-02

1 0.00025 9-9-02

Incinerator No. Lbs/dry ton Date
Lead (Pb)

Southerly WWTC Biosolids - Lead

0

500

1000

1500

2000

1980198119821983198419851986198719881989199019911992199319941995199619971998199920002001200220032004

Year

C

o

n

c

e

n

t

r

a

tio

n, m

g

/kg

AVG

PEAK

NEORSD Pretreatment Program
Lead (Pb)

NACWA - 16 POTWs

NACWA 2002 Survey - Lead in Biosolids

0

100

200

300

400

500

600

0 20 40 60 80 100 120 140

m

g/d

r

y kg
Lead (Pb)

NACWA - 16 POTWs

Lead Control Efficiencies

86.0

88.0

90.0

92.0

94.0

96.0

98.0

100.0

102.0

0 2 4 6 8 10 12 14

%

87.9

92.5

96.3

97.0

97.4

97.6

98.5

98.7

99.2

99.3

99.6

99.8

4 participants did not report their control efficiencies
Lead (Pb)

NACWA - 16 POTWs

NACWA2002 Survey- Lead Emission Rates

1.00E-04

1.00E-03

1.00E-02

1.00E-01

1.00E+00

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

lb

s/

d

ry

ton
Cadmium 

(Cd)
Cadmium 

No National Regulatory Limit 

Cd emissions are a function of the:

- concentration of cadmium in feed, 

- burning zone temperatures, and

- the cadmium control efficiency of the 

air pollution control train
Cadmium

Southerly WWTC (June 9 - 12, 1993)

0.023 0.005 0.002 0.004

Cd

(lbs/dry ton)

2 2.1 1.8 2

Feed Rates 

(tons/hr)

0.045 0.010 0.004 0.008

Cd

(lbs/hr)

No. 1 No. 2 No. 3 No. 4

4 Identical MHs with internal afterburners & 

venturi / impingement tray scrubbers
Cadmium

Southerly WWTC

Southerly WWTC - Cadmium in Biosolids

0

20

40

60

80

100

120

140

160

1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2005 2005 2006 2007 2008

Year

m

g

/

dry kg

Average

Peak
Cadmium Emissions

Southerly WWTC - Calculated

Southerly WWTC - Cadmium Emission 

0.0000

0.0020

0.0040

0.0060

0.0080

0.0100

0.0120

1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2005 2005 2006 2007 2008

Year

lb

s

/d

r

y

t

o

n in

cin

e

r

a

ted
Cadmium 

NACWA - 21 POTWs

Cadmium Concentrations in Biosolids 

1994 - 2000

0.0

20.0

40.0

60.0

80.0

100.0

120.0

140.0

0 20 40 60 80 100 120 140 160

mg/d

ry kg
Cadmium Control Efficiencies

NACWA - 21 POTWs

91.8%

92.3%

92.6%

92.8%

92.9%

94.0%

94.1%

94.6%

95.5%

97.0%

99.9%

65.6%

72.7%

76.7%

81.5%

83.5%

84.7%

85.8%

88.0%

90.4%

91.1%

CadmiumControl Efficiencies

0

20

40

60

80

100

120

0 5 10 15 20 25

%
Cadmium Emissions 

NACWA - 21 POTWs

425,000 dry metric tons incinerated in 2000

NACWACadmiumEmissions Survey

1.00E-05

1.00E-04

1.00E-03

1.00E-02

1.00E-01

1.00E+00

1994 1995 1996 1997 1998 1999 2000

lb

s/

d

r

y

ton

Max

Avg

Min
Cadmium Emissions (lbs/dt)

NACWA - 21 POTWs

Average 4.79E-03 1.64E-03 8.29E-05

2000 2.83E-03 1.18E-03 2.94E-05

1999 3.22E-03 1.31E-03 2.25E-05

1998 3.32E-03 1.36E-03 1.78E-05

1997 3.56E-03 1.29E-03 1.81E-05

1996 4.96E-03 1.57E-03 2.03E-04

1995 4.63E-03 1.76E-03 1.63E-04

1994 1.25E-02 2.99E-03 1.71E-04

Year Maximum Average Minimum

425,000 dry metric tons incinerated in 2000
Cadmium 

NACWA - 21 POTWs

CadmiumEmission Rates 

1994 - 2000

0

0.002

0.004

0.006

0.008

0.01

0.012

0.014

0 50 100 150

lb

s

/d

ry

ton
Mercury 

(Hg)
Mercury 

National Regulatory Limit 

NESHAPs = 3,200 grams/24-hours from all 

sources located at a site

Mercury emissions are a function of the 

mercury concentration in the feed 
Mercury

Southerly WWTC (June 9 - 12, 1993)

0.0008 0.00008 0.00001 0.00003

Hg

(lbs/dry ton)

2 2.1 1.8 2

Feed Rates 

(tons/hr)

0.0016 0.0002 0.00002 0.00007

Hg

(lbs/hr)

No. 1 No. 2 No. 3 No. 4

4 Identical MHs with internal afterburners & 

venturi / impingement tray scrubbers
Mercury

Southerly WWTC

SoutherlyWWTC - MercuryEmission Rates

0.00001

0.0001

0.001

0.01

0.1

1

1 2 3 4 5 6 7 8

lb

s/

d

ry

ton
Mercury

Southerly WWTC

3 0.0029 7-27-04

4 0.0018 9-11-02

2 0.0026 9-10-02

1 0.0025 9-9-02

Incinerator No. Lbs/dry ton Date
Mercury

Southerly WWTC

Southerly Biosolids Mercury Concentration

0.0

2.0

4.0

6.0

8.0

10.0

1/1/2000 1/1/2002 1/1/2004 1/1/2006 1/1/2008 1/1/2010

mg

/kg
Calculated Mercury Emissions 

NACWA 2002 Survey - 11 POTWs 

(Assumes 0% control efficiency)

NACWAStudy - MercuryEmission Rates

1.00E-06

1.00E-05

1.00E-04

1.00E-03

1.00E-02

1.00E-01

1.00E+00

1 2 3 4 5 6 7 8 9 10 11

lb

s/

d

r

y

ton
Actual Mercury Emissions from SSIs 

• 2003 EPA requests actual mercury emissions from SSIs

• NACWA asked for mercury control efficiencies from its 

members that incinerate and air emissions test data.

• Reported Control Efficiencies: 0 - 80% ???

• Limited amount of reliable test data

• Given the lack of reliable CEs and actual air emissions test 

data, NACWA could not determine actual emissions. 
WERF Mercury Study

• In 2006, WERF retained Frontier Geosciences to conduct a 

study to determine ways to minimize mercury emissions 

from biosolids incinerators.

Findings:

• No confidence in the reported CEs or reported air 

emissions due to differing test methods. 

• Different test methods used to determine mercury in the 

plant’s influent, effluent, biosolids, scrubber water 

influent & effluent, exhaust stack gases and ash. 
WERF Mercury Study

• Final Report to be released this Fall. 

- Will included recommended test methods 

- Will state that the most effective methods for minimizing 

mercury emissions from biosolids incinerator is 

through source control.

- Dental Amalgam Separators at Dentist Offices
Dioxins 
Dioxins 

No National Regulatory Limit 

Function of concentration in feed of 

a. Dioxin 

b. Dibenzofurans 

c. Co-Planer PCBs 

Dioxins = Dioxin + Dioxin-like Compounds
Dioxins

• 1994 EPA Estimated Dioxins Emissions

Total = 9,200 grams (TEQ) 

SSIs = 23 grams (TEQ) (0.25% of total)

• EPA Testing of SSI in 1987 

Emission Rate = 0.027 μg (TEQ) /dry kg

using 1989 International TEF System

Biosolids Incinerated = 0.865 million m. tons

= 23 grams (TEQ)
Municipal Waste 

and Medial Waste 

incinerators are 

responsible for 

~ 90% of the 

Dioxin emissions
Dioxins

• EPA announces that it will investigate the 

possibility of regulating Dioxins emissions 

from SSIs & Dioxin in land applied sewage 

sludge under Round II of the Part 503 

Regulation

• NACWA conducts survey of dioxins in sewage 

sludge and emitted from SSIs
Dioxins - SSIs

• NACWA 1994 SSI Survey (Cost ~ $35,000/test)

– 11 SSIs 
Dioxins - SSIs

• NACWA 1994 SSI Survey

NACWASurvey - Dioxins Emissions (1995)

1.00E-04

1.00E-03

1.00E-02

1.00E-01

1.00E+00

1 2 3 4 5 6 7 8 9 10 11

lb

s/

d

ry

ton
Dioxins - SSI

1995 NACWA Data from 11 SSIs

Emission Rate = 0.00536 μg (TEQ) /dry kg

using 1989 International TEF System

NACWA + EPA Data from 14 SSIs

Emission Rate = 0.00873 μg (TEQ) /dry kg

using 1989 International TEF System
Dioxins - SSIs

Gene Riley of U.S. EPA conducted additional 

Dioxins testing of SSIs in 1999

Source Characterization for SSI Emissions

Contract No. 68-D-99-009 (Battelle)

NACWA + EPA Data from 14 SSIs

Emissions from SSIs 

= 0.00873 μg (TEQ) /dry kg x 0.865 metric tons

= 8 grams (TEQ)/year (0.087% of total)
Dioxins - SSIs 

December 21, 2001 Federal Register:

EPA announced that:

“... numeric standards or management practices are not 

warranted for dioxin and dioxin-like compounds in 

sewage sludge that is incinerated in a sewage sludge 

incinerator."

Cancer Risk to the HEI < 2.1 x 10-6
Dioxins - Sewage Sludge 

December 23, 1999 Federal Register:

EPA Proposes a Dioxins limit of 300 ppt (TEQ) for 

sewage sludge that is land applied

NACWA conducts another survey of Dioxins 

in Biosolids to complement EPA’s survey
Dioxins - Sewage Sludge 

• 1994 - 1995 NACWA Survey

- 104 Biosolids Samples from 75 POTWs 

• 2000 EPA Survey

- 112 Biosolids Samples from 99 POTWs 

• 2001 EPA Survey

- 200 Biosolids Samples from 171 POTWs 
Dioxins - Sewage Sludge 

NACWA 1994 - 1995 Survey

Dioxins Concentrations = 5.7 - 368 ppt-TEQ

Non-Detects

@ Det. Limits @ Zero

Average 113 ppt-TEQ 95 ppt-TEQ

Median 78 ppt-TEQ 57 ppt-TEQ 
Dioxins - Sewage Sludge 

NACWA 2001 Survey

Dioxins Concentrations = 7.1 - 256 ppt-TEQ 

plus one outlier 

of 

3,590 ppt-TEQ

*****************************************************

Average = 48.5 ppt-TEQ 

Median = 21.7 ppt-TEQ 
Dioxins - Sewage Sludge 

EPA 2000 NACWA 2001

Average 49.3 48.5

Median 24.2 21.7

(ppt-TEQ) 

12 POTWs participated in both surveys
Dioxins - Sewage Sludge 

0

10

20

30

40

50

60

0-10 10-30 30-

100

100-

200

200-

300

>300

Dioxins Concentrations (ppt-TEQ)

P

e

r

c

e

n

t

o

f

S

a

m

ples

EPA

AMSA
Di

oxins -Sewage Sludge 

112

75

37

0

20

40

60

80

100 120

1994 1998 2000 Year

Dioxins Concentrations

(ppt-TEQ)

124

56 48

0

50

100 150

1994 19982000

Year

Dioxins Concentrations

(ppt-TEQ)

NEORSD 

Southerly 

WWTC

NEORSD 

Westerly 

WWTP
Dioxins 

May 6, 2005 Federal Register: 

EPA reconfirms 12-21-2001 announcement and states 

that there would not be numerical standards for sewage 

sludge that is land applied.
Possible Impact of Potential MACT 

Standards on POTWs that Incinerate
• Install additional and separate systems to 

reduce NOx, particulate and CO emissions

• Expansion of existing facilities

- no room to add equipment

• Curtail or abandonment of incineration

- substantial increases in biosolids management costs

• Obtain new Permits if biosolids is reclassified 

as a solid waste 

Possible Impact of MACT Standards 
Possible Impact MACT Standards

• Southerly WWTC 

– Annual Projected Biosolids O&M Costs (2014)

210,000 $80 $16.8 million

Land 

Application

Landfilling 210,000 $86 $18.1 million

Incineration 210,000 $31 $6.5 million

Total 

Cost

Cost

per wet ton

Wet U.S. tons 

Biosolids
Cost of Reducing Southerly’s 

Air Emissions

Possible Impact MACT Standards
Cost of Reducing Southerly’s 

Air Emissions after 2013

Incinerators:

Particulate Matter - 6 Tons/yr 

Wet Electrostatic Precipitators

Capital Cost: ~ $10 million

O&M Costs: ~ $0.25 million/yr

PM Reduction: ~ 3 tons/yr
Cost of Reducing Southerly’s 

Air Emissions after 2013

Incinerators: SO2- 6 tpy

NOx - 44 tpy

Sodium Hydroxide added to 

Scrubbers

Capital Costs: $0.5 million 

O&M Costs: $ 0.7 million/yr

Reductions: 

~ 3 tpy SO2; ~ 4 tpy NOx ?
Cost of Reducing Southerly’s 

Air Emissions after 2013?

Incinerators:

Nitrogen Oxides - 44 Tons/yr

Urea added to 

Exhaust Gases

Capital Costs: $ 5 Million 

O&M Costs: $500,000/yr

NOx Reduction: 

4 - 12 tons/year 

Urea converts NOx to N20
Cost Effectiveness of the Additional Controls

($ per ton of pollutant removed ) 

Urea - - > $60,000

- $120,000* $90,000*

Sodium

Hydroxide

$250,000 - -

Wet

ESP

PM SO2 NOx

* Capital and O&M Costs split between the two

Cost of reducing Southerly’s 

Air Emissions after 2013?
$20.7 million 8 - 16 18 - 36%

Oxides of 

Nitrogen

$5.7 million 3 50%

Sulfur

Dioxide

$ 15 million 3 50%

Particulate

Matter

%

Reduction

Emissions

Reduction

(ton/yr)

Total Cost

(cap + O&M)

Further reducing Southerly’s 

Air Emissions 

2014 - 2033
Environmental Impacts of 

MACT Standards for SSIs
Environmental Impact of 

MACT Standards

• Insignificant Reduction in Air Emissions

- SSIs are already adequately regulated under: 

- 40 CFR Part 503 

- 40 CFR Part 60 - Subpart 0 

- Clean Air Act (Title V, FESOP, etc) 

- various State & Local Regulations 

• Elimination of numerous SSIs

- Increase in landfilling

- Increase in trucking

- Increase in Greenhouse Gas Emissions
Summary
Summary

1. Incineration is an technically sound, environmentally 

responsible, and cost-effective biosolids 

management option utilized by 124 POTWs

2. 850,000 - 1.2 million dry tons ( 3 - 5 million wet tons) 

of biosolids are incinerated annually in the 

United States 

3. POTWs must treat what they receive

4. Part 403 and 503 Regulations drove POTWs to 

control upstream sources to the extent feasible
Summary 

5. There is significant variability in sewage 

received by different POTWs that results 

in the site-specific composition and 

quality of biosolids.

6. There is variability in emissions from 

identical incinerators located at the same 

POTW.

Air emission test results can substantially 

vary from test to test on the same 

incinerator.
Summary 

7. Biosolids are totally different from medical 

waste, municipal solid waste and hazardous 

waste

- SSIs should not be regulated with medical waste, 

municipal solid waste and hazardous waste 

incinerators.

8. Separate SSI Subcategories are necessary for

- Multiple Hearths

- Fluidized Beds

- Electric Arc 

Due to different emission profiles
Summary

9. Control Measures:

- Congress allows POTWs to meet MACT using 

control measures that include pretreatment 

- Limited ability to control upstream dischargers 

is more effective for targeted HAP 

compounds (less effective for nitrogen, 

sulfur, carbon)
Next Steps
Next Steps

1. EPA to review NACWA information and 

identify data gaps

NACWA will assist in filling data gaps

2. Others
Contact Information

Bob Dominak

Residuals & Air Emissions Manager

Northeast Ohio Regional Sewer District

3900 Euclid Avenue

Cleveland, OH 44115

Phone: 216-881-6600 ext. 6405

E-Mail: dominakr@neorsd.org
Sewage Sludge Incinerator Information Meeting With 

The National Association of Clean Water Agencies 

August 25, 2009 

8:30 am to 12:30 pm (Room: E301, Phone: 919-541-4332) 

Attendance

EPA

Amy Hambrick 

Ketan Patel 

Martha Smith 

Charlene Spells 

Larry Elmore 

Susmita Dubey 

Ron Myers 

Brian Shrager 

Rick Stevens 

Robin Dunkins 

Lyn Luben 

ERG

Amber Allen 

NACWA

Robert Dominak 

Chris Hornbeck 

Mark Filnert 

Doug McWilliams 

8:30 am-8:45 am Welcome & Introductions 

• Meeting purpose 

• Who’s who 

• Agenda 

• Logistics – bathrooms, cafeteria 

8:45 am – 11:30 am SSI presentation by Bob Dominak 

• History and background information on the management of 

Biosolids (sewage sludge) 

• Incineration of Biosolids 

• Air pollution control devices 

• Energy recovery methods and benefits 

• Current incinerator regulations 

(10:00 am-10:15 am) BREAK 

• CAA section 129 pollutants 

• Potential impact of MACT Standards 

• Environmental Impact of MACT Standards 

• Summary 

(11:30 am – 11:45 pm) BREAK 

11:45 am- 12:30 pm Open Discussions 

12:30 pm Meeting Adjourned