One Set of MACT Standards for all 231 Biosolids Incinerators 

(Potential Impact on the 167 Multiple Hearth Incinerators) 

If a decision is made develop a single MACT Standards for both multiple hearth 

incinerators and fluidized bed incinerators instead of separate MACT Standards for the 

two different types of biosolids incinerator, the MACT Standards for all biosolids 

incinerators would be based on emissions from the newest fluidized bed incinerators. 

In general, emissions of pollutants that would be subject to MACT Standards 

from fluidized bed incineration systems for carbon monoxide, oxides of nitrogen and 

particulate matter, at a minimum, are lower than those from multiple hearth incineration 

systems, for the following reasons: 

1. Higher turbulences in the fluidized bed results in increased combustion efficiencies, 

thereby reducing particulate matter emissions. 

2. Fluidized beds are designed with an internal afterburning zone which substantially 

 increases the residence time, thereby reducing carbon monoxide, total hydrocarbons 

(i.e., the surrogate for all potentially toxic emissions, including dioxins), and particulate 

 matter emissions. 

3. The vast majority of fluidized bed incinerators are designed to be operated 

autogenously, where auxiliary fuel is only required to bring the incinerator up to 

 operating temperatures. Autogenous operations results in substantially lower carbon 

dioxide and nitrogen oxide emissions. 

4. Some of the newer fluidized bed systems are equipped with pollution control systems 

 that include high efficiency multi-venturi scrubbers and wet electrostatic precipitators 

 that also results in lower particulate matter emissions. 

 While these air pollution control devices further reduce metal emissions at the 

specific sites, it should be noted that metal emissions are also a function of the 

concentration of metals in the biosolids feed to the incinerator. 

 As a result, the vast majority, and possibly all of the existing multiple hearth 

incinerators would not be able to simultaneously meet MACT Standards for carbon 

monoxide and nitrogen oxides, or comply with a particulate matter MACT Standard 

based on the average emissions from the best operating (12 percentile) of the existing 

fluidized bed incinerators. In addition, metal concentrations in biosolids can vary greatly 

from plant to plant and are based on industrial loadings and industrial pre-treatment 

programs. 
Publicly Owned Treatment Works (POTWs) with multiple hearth incinerators 

wishing to continue to manage their biosolids through incineration would most likely 

have to replace their existing units with new fluidized bed incinerators. The replacement 

costs would be substantial. 

The total Bid Price to purchase and install three new 96 dry ton per day fluidized 

bed incinerators in a new incineration complex at the Cincinnati Mill Creek WWTP in 

2007 was roughly $58 million. Engineering costs associated with the design and 

construction of the new incineration complex were roughly $7 million. 

In November 2008, the Northeast Ohio Regional Sewer District (Cleveland, Ohio) 

opened bids on the procurement of three new 100 dry ton per day fluidized bed 

incineration systems at the Southerly WWTC. The cost to procure the incinerators, air 

pollution control train and ancillary equipment was approximately $ 36 million. Bid to 

construct a new dewatering/incineration/turbine generator complex and the installation of 

the fluidized bed incinerators in the new incineration complex will be opened on October 

30, 2009. 

 Based on recent bids, the total capital cost to replace an existing multiple hearth 

incinerator with a new fluidized bed incinerator would be in the range of $18 Million to 

$25 Million. Since fluidized bed incinerators have a higher feed capacity than multiple 

hearth incinerators, we are assuming that 130 new fluidized beds would be required to 

replace the existing 167 existing multiple hearth incinerators. As a result, the total capital 

cost to replace the 167 multiple hearth incinerators with new fluidized bed incinerators 

could be in the range of $ 2.3 - $ 3.3 billion. 

The cost to abandon the multiple hearth incinerators and initiate a land 

application, distribution & marketing, or a landfilling program will be addressed in a 

future MACT Standards cost impact report, along with impacts of a single MACT 

Standards on fluidized bed incinerators who emissions are higher than the average of the 

top 12 percentile. 

RPD 

10-30-09