Information to the EPA: 

Proposed New Wastewater Incinerator Regulations 

Recommendation: 

For Modern Process Controls 
BACKGROUND:

Subject: Stakeholders meeting of EPA, AMSA (now NACWA), WEF 

September 17 1997: 

The purpose of the meeting was to inform the stakeholders of the status of the proposed 

emissions legislation, where the project was headed, and to address issues of concern. 

Dr. Falgout, of Pacific Environmental Services, who is managing the investigation for the EPA, 

stated during the course of the meeting: 

" Dr. Falgout noted that the number one factor in determine the performance of a sewage sludge 

incinerator is the quality and the consistency of the feed rate of the sewage sludge to the 

incinerator. " 

Feed rate of sludge cake to the incinerator can be controlled by the use of Mass Flow Control 

algorithms, and sensors which enable the mass balance of the dewatering unit process to be 

dynamically determined. 

From EPA Office of Air Quality Control (OAQC): 

From: Crumpler.Gene@epamail.epa.gov

Sent: Thursday, March 27, 2003 9:03 AM 

To: Peter Brady 

Subject: Re: Mass Flow Control 

Peter; 

 I would agree with Dr. Falgout's statement. I have been working 

with incineration of sewage sludge and earlier with RCRA and PCB 

incineration for 27 years. With any type of incineration of waste 

materials, consistent feed of the waste materials is extremely important 

to maintain stable operation and meet continuous monitoring permit 

requirements. 

 As Dr. Falgout stated, in the investigation of MACT for Sewage 

Sludge Incinerators, we considered specifying some type of requirement 

for maintenance of consistent feed rates. However, as you are aware, 

OAQPS/ESD finally concluded that a MACT Standard under both Section 129 

and 112 of the CAA was not justified. In part this decision was made 

based on the existing requirements already being enforced under Part 

503. 

 As to my specific experience with multiple hearth incinerators 
over the last 19 years, the maintenance of consistent feed conditions is 

critical for stable operation of these type of sewage sludge 

incinerator. Sludge feed needs to be consistent in both moisture 

content, dry solids mass feed rate and total thermal input. Swings in 

the sludge feed will cause large changes in heath-to-hearth temperatures 

and the load going to the air pollution control systems. This has been 

observed in the numerous tests that have been conducted over the time 

period from 1986 to 1999. These swings immediately effect the monitoring 

of THC/CO, the main continuous monitoring requirement for sewage sludge 

incinerators in Part 503. 

 I hope this is of some help in summarizing my experience on this 

subject. 

Sincerely 

Eugene Crumpler 

Environmental Engineer 

Office of Air Quality Planning and Standards 

USEPA, RTP, NC 
RECOMMENDATIONS:

From: Tim.Shea@CH2M.com [mailto:Tim.Shea@CH2M.com] 

Sent: Wednesday, December 10, 2008 6:53 AM 

To: pbrady@alpinetechnology.com

Cc: Smith.James@epamail.epa.gov

Subject: Process control sections - Chapter 18

Dr. Jim Smith and I would like to request that you forward the message below to Mr. Dominak 

for his consideration in the preparation of the second draft of Chapter 18.

Thanks,

Tim

Timothy G. Shea, Ph.D, PE, BCEE

Board Certified Environmental Engineer

Senior Principal Technologist

CH2M HILL

15010 Conference Center Drive, Suite 200

Chantilly, VA 20151

Tel 703-376-5245

Fax 703-376-5745

Cell 703-887-7283

tshea1@ch2m.com

CHAPTER 18 - THERMAL OXIDATION AND ENERGY RECOVERY 

We appreciate the tremendous effort to get this chapter together. This first draft includes a great 

deal of information and demonstrates the hard work of the Chapter Lead Author and his 

team. We do wish to know who the co-authors were for each section, as it will assist us 

in expediting the peer review process.

We also have a technical concern regarding the text on process optimization. We live in the age 

of solids sensors yielding real time information for process control, but this is not evident in the 

draft for Section 11. There are now accurate and reliable sensors for measuring the percent 

solids going through the process train, with in a slurry form or as cake. These instruments 

include cake solids sensors for measuring dewatered cake solids in pipeline. 

The section on I&C in the draft text is not commensurate with where modern optimization 

practice is going. At page 246 et seq, the main requirements of a modern process control system 

are not addressed. The automation definition is 35 years old from a company no longer in the 

business (Babcock). 

 The main issues today are better integration of the dewatering and incineration process- that is 

mass flow control to the incinerator. This is possible today because of the above-noted advances 

in solids sensors. 
We have seen where the implementation of control systems with these types of instrumentation 

resulting in increased system capacity while lowering the consumption of fuels and reducing 

emissions of air pollutants, ultimately yielding a performance that is more efficient, less costly 

and safer.

We would like to thank you in advance for your attention to these points in the second draft.

J. E. Smith, Jr., DSc., BCEEM (MS-190)

Senior Environmental Engineer & Chair

USEPA's Pathogen Equivalency Committee

National Risk Management Research Laboratory

26 West Martin Luther King Drive

Cincinnati, Ohio 45268

Tel: 513-569-7355

Fax: 513-569-7105

Email: smith.james@epa.gov