Final Notes from Site Visit at Allegheny Energy’s Hatfield’s Ferry Steam Electric Plant on 

February 3, 2010

EPA conducted a site visit at Allegheny Energy’s Hatfield’s Ferry Steam Electric Plant

(Hatfield’s Ferry) located in Masontown, PA on Wednesday, February 3, 2010 to learn about the 

operations at the plant, including the operation of the flue gas desulfurization (FGD) wastewater 

treatment system. Table 2 identifies the site visit participants.

Plant Overview

• Hatfield’s Ferry operates three coal-fired electric generating units. Table 1 below 

contains some general information on the current operation of each steam electric 

generating unit.

Table 1. Hatfield's Ferry Steam Electric Plant Units Operation

Unit

Installation 

Date

Gross Net

Capacity 

(MW)

Particulate 

Control NOx Control SO2 Control

1 1969 570 ESP (cold-side) Overfire air FGD (June 2009)

2 1970 570 ESP (cold-side) Overfire air FGD (October 2009)

3 1971 570 ESP (cold-side) Overfire air, 

SNCR

FGD (October 2009)

• On average, Hatfield’s Ferry burned 3.6 million tons of coal per year from 1993-

2009. All three units burn a blend of approximately 75% bituminous and 25% 

powder river basin (PRB) coals. Currently the coal blend has approximately 2.3% 

sulfur and 0.06-0.15% chlorides. The FGD systems are designed for coals with up 

to 4% sulfur; therefore, depending on coal prices, Hatfield’s Ferry will likely 

switch to burning coal with higher sulfur content in the future. Based on this 

expectation, Hatfield’s Ferry stated that they will probably burn 100% bituminous 

coal in another year or two.

• Hatfield’s Ferry receives coal and limestone shipments via barge.

• Fly ash is handled dry and sent pneumatically to a silo. From the silo, dry fly ash

is either transported by truck to the landfill or by barge to be sold for beneficial 

reuse. Currently, dry fly ash is being used for mine reclamation projects. 

Hatfield’s Ferry has used dry fly ash handling systems since the plant began 

operating.

• Hatfield’s Ferry handles the bottom ash using a wet system. The plant sluices the 

bottom ash to hydrobins for dewatering. Overflow from the hydrobins is 

transferred to the concrete ash settling basins. From the settling basins, the 

wastewater is neutralized with calcium hydroxide to a pH of 6-9 and sent to the 

lagoons. The bottom ash dewatered in the hydrobins is put directly into truck and 

most of it is sold.
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• The plant has two lagoons, which are lined with clay. Only one lagoon is in 

service at a time, while the other lagoon is cleaned out. Hatfield’s Ferry switches 

the operation of the lagoons approximately every two years.

• Hatfield’s Ferry operates an on-site landfill, which is not lined. However, the

plant is expanding the landfill and the new portion will be lined with a synthetic 

liner. The new landfill will hold all FGD waste. All leachate from the new landfill 

will be transported to a five acre leachate storage impoundment (LSI). Leachate 

will be monitored for solids and metals and discharged to the river. The landfill 

was originally designed to last 20-30 years. However, because the plant is adding 

FGD gypsum to the landfill, the plants expects that the landfill will only last 

seven years.

• The landfill is built over a strip mine. Acid mine drainage from this strip mine is 

treated with a passive wetland treatment system. Wastewater is pumped from two 

collection sumps to an equilibration pond. The water flows through the wetland 

where metals such as iron, aluminum, and manganese are removed. Manganese is 

removed by manganese oxidizing bacteria which grows on the limestone bed in 

the treatment system. The wetland discharges to a pond, which then discharges to 

Little Whitney creek via outfall 007.

• Coal pile runoff is sent to the ash settling basins for treatment.

Flue Gas Desulfurization System

• Hatfield’s Ferry uses recycled lagoon water to make up a maximum of 50% of the 

water for the FGD system. The remainder of the make-up comes from the 

Monongahela River. Hatfield’s Ferry can only use up to 50% lagoon water 

because it is hard to control the pH above this percentage. The plant uses lagoon 

water as make-up because Pennsylvania Department of Environmental Protection 

(DEP) requested that the plant limit their discharge flow. All wastewater 

generated at the plant, except for FGD wastewater, is sent to the lagoon. This 

includes ash sluice water, floor drain wastes, and boiler wash water.

• The FGDs are all limestone forced oxidation systems. They were designed by

Babcock & Wilcox and have two dual flow trays. One tray is located about six

feet above the flue gas inlet. The second tray is located six feet above the first 

tray. The first level of spray headers are located six feet above the second tray. 

The system has five spray headers. The plant typically operates only four of the 

five spray headers at a time. 

• Hatfield’s Ferry operates three ball mills, one per unit, to crush the limestone. The 

limestone preparation process is designed to produce a limestone slurry with 28% 

solids; however, the limestone slurry is typically around 22-25% solids.

• All three FGD systems have a design sulfur dioxide removal efficiency of 95% 

and an actual sulfur dioxide removal efficiency of 97-98%. 
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• Hatfield’s Ferry blows down from the FGD scrubber based primarily on the level 

of solids. Once the solids concentration reaches 21 percent solids, the plant blows 

down to reduce the solid level to approximately 16-17 percent. The plant also 

monitors the chloride level in the absorbers; however, by maintaining the correct 

level of solids, the plant maintains an adequate chlorides level in the absorber at 

around 10,000 ppm without the need for additional blowdown. For all three units, 

blowdown from the absorbers occurs in six hour increments with four to five 

hours in between each blowdown. 

• Blowdown from each absorber is sent directly to a set of primary hydrocyclones

(one for each unit). Underflow from each primary hydrocyclones is sent to one of 

four vacuum filters for dewatering gypsum. Each unit has the ability to transfer 

the gypsum to two vacuum filters, which allows blowdown and dewatering to 

occur even if one of the vacuum filters is undergoing maintenance. Filtrate from 

the vacuum filters is transferred to the reclaim tank. Overflow from the primary 

hydrocyclones is either sent to the secondary hydrocyclones or sent to the reclaim 

water tank, which is recycled back to the absorbers. Secondary hydrocyclone

underflow is transferred to the reclaim tank, while secondary hydrocyclone

overflow goes to the wastewater treatment system.

• The plant is designed to produce commercial grade gypsum, but the plant does not 

have any contracts in place to sell the gypsum. The dewatered gypsum contains

less than 10% moisture. The plant is not washing the gypsum to remove chlorides 

because the plant is not marketing gypsum. Additionally, the plant has a limit on 

the average FGD discharge flow rate for the month, which cannot exceed 160 

gpm. Plant personnel stated that if the plant washed the gypsum, the flow

additional water would cause them to be above the flow rate limit. The gypsum is 

transported to an on-site landfill via truck. Wastewater collected in the sump from 

the gypsum pile is transported to the lagoons.

• There are sample points to collect the secondary hydrocyclone overflow off each 

of the three secondary hydrocyclones. However, there is no sample point in which 

to collect the combined secondary hydrocyclone overflow.

FGD Wastewater Treatment System

• A simplified diagram of the FGD wastewater treatment system at Hatfield’s Ferry 

is included as Attachment 1.

• In June 2009, Hatfield’s Ferry began sending wastewater to the FGD wastewater 

treatment system. The wastewater treatment system first discharged on June 30, 

2009.

• The secondary hydrocyclone overflow is first collected in the equilization (EQ) 

tank. Wastewater entering this tank typically contains 3-5 percent solids. 

Primarily overflow from the secondary hydrocyclones enters into the EQ tank. 

The EQ tank also holds other wastewater, including treated FGD wastewater and 

wastewater from the sumps in the FGD wastewater treatment building. Hatfield’s 
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Ferry recycles treated FGD wastewater back to the EQ tank to keep the EQ tank 

at a sufficiently high level to keep the agitator operating and flow continually 

running through the wastewater treatment system. Sumps in the wastewater 

treatment system include filter backwash and filtrate from the filter presses that 

dewater the sludge from the clarifiers. Sumps from the dewatering area can also 

empty into the EQ tank. Sumps in the limestone preparation area do not empty 

into the EQ tank. 

• From the EQ tank, FGD wastewater flows into the bottom of reaction tank 1.

Hatfield’s Ferry adds lime to the top of the tank to increase the pH from 5.5 S.U.

(pH in the absorber) to 8.5-9.0 S.U. The plant uses service water is used to create 

the hydrated lime on site. The plant also adds organosulfide (Nalmet 1689 at the 

bottom of reaction tank 1.

• The overflow from reaction tank 1 flows to reaction tank 2. The plant adds ferric 

chloride to the top of the reaction tank. 

• The overflow from reaction tank 2 enters a box, which splits the flow to two 

solids contact clarifiers. Just prior to splitting the stream, Hatfield’s Ferry adds a 

polymer to the wastewater. At the time of the site visit, one clarifier was out of 

service and being repaired because the lining was peeling off; therefore,

Hatfield’s Ferry is sending all wastewater to the other clarifier. The solids contact

clarifier contains a large cone in the center, which is open at the bottom. 

Wastewater is pumped into the center of this cone. Solids settle down to the 

bottom of the clarifier. In order for wastewater to exit the clarifier, it must go out 

the bottom of the center cone and then return back to the surface. This process 

encourages solids to remain at the bottom of the clarifier. Sludge scraper arms at 

the bottom of the clarifier move the solids to the center hopper where it can be 

removed from the clarifier. 

• Hatfield’s Ferry the majority of the clarifier solids is sent to the dewatering tank 

and then pumped to filter presses to create sludge cake with 75% solids. The 

remainder of the clarifier solids are recycled back to reaction tank 1 to act as 

nucleation sites for the solids entering the system. The dewatered solids are 

transferred to the landfill with the gypsum. The filtrate from the filter presses is 

collected in the filtrate sump, which is transferred to the EQ tank.

• The overflow from the clarifier is transferred to continuous backwash gravity 

filters, which use sand as the filtration media. Hatfield’s Ferry adds hydrochloric 

acid to the wastewater prior to the filters to raise the pH to 7.0 S.U. The backwash 

from the continuous backwash gravity filters is transferred to the filtrate sump.

• After passing through the gravity filters, the treated wastewater is sent to the

treated wastewater storage tank. Wastewater in this tank is either recirculated 

back to the EQ tank or discharged.

• The plant takes composite and grab samples at a sample tap off of the treated 

wastewater storage tank. This sample point only collects wastewater that is being 
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discharged and does not include wastewater that will be recirculated back to the 

EQ tank. 

• Discharge from the wastewater treatment system is not continuous; this is largely 

because treated wastewater is sent back to the beginning of the treatment system 

in order to make sure that wastewater is circulating through the system at all 

times. The plant attempts to keep the average daily discharge lower than 160 gpm 

because the average monthly discharge flow rate cannot exceed 160 gpm (a limit 

set by the plant’s NPDES permit). Plant personnel stated that at any individual 

time, the plant may have no flow leaving the FGD wastewater treatment system, 

while at other times, the discharge flow could be 600 gpm. The average daily 

discharge flow from the FGD wastewater treatment system (IMP-306) is typically 

about 120 gpm.

• Treated FGD wastewater (internal outfall 306) and lagoon wastewater (internal 

outfall 206) are combined and discharged via the final outfall 006. The plant 

monitors outfall 006 for pH, total dissolved solids (TDS), total suspended solids 

(TSS), oil and grease, cadmium, thallium, selenium, flow, mercury, and sulfate. 

Hatfield’s Ferry has limits for oil and grease, mercury, cadmium, thallium, 

selenium, TDS, TSS, and sulfate.
Table 2. Site Visit Attendees

Name Organization (Representing) Telephone E-mail

Bill Cannon Allegheny Energy 724-838-6018 wcannon@allegheneyenergy.com

Randy Jones Allegheny Energy, Hatfield’s Ferry 724-966-3016 rjones4@alleghenyenergy.com

Wayne Lingenfeller Allegheny Energy 724-838-6457 wlingen@alleghenyenergy.com

Donna Hill Southern Company/UWAG 205-257-5234 dbhill@southernco.com

Josh Hall EPA 202-566-1002 hall.josh@epa.gov

TJ Finseth Eastern Research Group 703-633-1698 thomas.finseth@erg.com

Becky Schwantes Eastern Research Group 703-633-1715 becky.schwantes@erg.com