Draft Hatfield’s Ferry Site Visit Notes Draft 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

, Fe bruary 3, 2010 to learn about the operations at the plant

, including the operation of the flue gas desulfurization ( FGD ) wastewater treatment system

. Table 1 identifies the site visit participants.

Plant Overview

**•** Hatfield’s Ferry operates three coal

- fire d electric generating units

. The table below contains some general i nformation on the current operation of each steam electric generating unit.

Unit Installation
Date Gross Net Capacity

(MW) Particulate
Control NOx Control SO 2 Control

1 1969 570 ESP (col d

- 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

, Hatfi eld’s Ferry burned 3.6 million tons of coal per year from 1993

- 2009. All t hree 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 % chloride s

. T he FGD systems are designe d for coal s with up
to 4% sulfur ; therefore, dependi ng on coal prices

, Hatfield’s Ferry will li kely
switch to burning coal with hig her 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 c oal 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 bein g used for mine reclamation projects. Hatfield’s Ferry has used dry fly ash handl ing systems since the plant began operating.

**•** Hatfield’s Ferry handles the b ottom ash using a wet system

. The plant sluices the
bottom ash to h ydro bins for dewatering . Overflo w from the hydro bins is
transferred to the concrete ash settling basins. From the settling basins, t he
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 t ruck and
most of it is sold

.Draft Hatfield’s Ferry Site Visi t Notes **•** The plant has two lagoons , which are lined with clay

. Only one lagoon is in service at a time, while the other lagoon i s cle a n ed out. Hatfield’s Ferry switches the operation of the lagoons approximately every two years

.

**•** Hatfi eld’s Ferry operates an on

- site landfill, which is not lined. However, t he 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 transp orted 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 t wo collection sumps to an eq uilibration pond. The wa ter flows through two wetlands
where m etals 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 two wetlands discharge 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 G as Desulfurization System

**•** Hatfield’s Ferry uses recycled lagoon water to make up 50% of the water for the FGD system. The remainder of the make

- up comes from the Monon gahela River

. Hatfield’s Ferry can only use 50% lagoon water because it is hard to control the pH above this percentage

. The plant uses lagoon water as make

- up because

Penn sylvania 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 FG D s are all limestone forced oxidation system s. They were designed by

B abcock & W ilcox and have two dual flow t rays. 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 s pray 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 dio xide removal efficiency of 97

- 98%

.Draft Hatfield’s Ferry Site Visi t Notes **•** Hatfield’s Ferry blows d own 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 pe rcent . The plant also
monitors the chloride level in the absorber s; h owever, by maintaining the correct
level of solids, the plant maintains an adequate chlorid e s level in the absorber at
around 10,000 ppm without the need for additional blowdown . For all three units,
blow down from the absorbers occurs in six hour increments with four to five
hours i n between each blowdown

.

**•** Blow down from each absorber is sent directly to a set of primary hydro cy clone s (one for each unit). Underflow fr om each primary hy drocyclones is sent to one of four vacuum filters for dewatering gypsum. Each unit has the ab ility to transfer the gypsum to two vacuum filters, which allows blowdown and dewatering to

occur even if one of the vacuum filter s is undergoing maintenance. Over flow from the primary hydrocyclone s is either sent to the secondary hydrocyclone s 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. [QUESTION
FOR HATFIELD’S FERRY: To where is the filtrate from the vacuum filters transferred?]

**•** The plant is designed to produce commercial grade gypsum, but the plant does not have any contracts in place t o sell the gypsum

. The dewatered gypsum contains
less than 1 0% 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 m onth, which cannot exceed 160

gpm. Plant personnel stated that i f the plant washed the gypsum, the flow
additional water would cause them to be above th e 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.

**•** Ther e are sample points to collect the secondary hydrocyclone overflow off each of the three secondary hydrocyclone s. 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 A ttach ment 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 firs t collected in the equilization (EQ) tank. Wastewater entering this tank typically contains 3

- 5 percent solid s

. Primarily overflow from t he secondary hydrocyclone s ent ers into the EQ tank. The EQ tank also holds other wastewater

, including treated FGD wastewater andDraft Hatfield’s Ferry Site Visi t Notes wastewater from the sumps in the FGD waste water treatment building

. Hatfield’s Ferry recycles t reated FGD wastewater back to t he 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 wast ewater treatment system include filter backwash and filtrate from the filter p resses 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 l ime 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 s ervice water is used to create the hydrated lime on site

. The plant also adds o rganosulfide (Nal met 1 689 at the
bottom of reaction tank 1

.

**•** The ove rflow from reaction tank 1 flows to reaction tank 2. The plant adds f erric
chloride t o the top of th e reaction tank.

**•** The overflow from reaction tank 2 enters a box, which splits the flow to two
solids contact clari fiers

. Just prior to split ting 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 be cause the lining was peeling off ; therefore, Hatfield’s Ferry is sending all waste water 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 ex it 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 ho pper 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 recyc led back to reaction tank 1 to act as nucleation sites for the solids entering the system. Th e dewater e d solids are transferred to the landfill with the gypsum. The filtrate from the filter presses is
collected in the filtrate sump, which is transferred t o the EQ tank.

**•** T he 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 b ackwash
from the continuous backwash gravity filters is transferred to the filtrate sum p.

**•** 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.Draft Hatfield’s Ferry Site Visi t Notes **•** 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 discharged and does not include wastewater that will be recirc ulated 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 th e system at all times. The plant attempts to keep the average daily discharge at 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, th e plant may have no flow leaving the FGD wastewater treatment system, while at other time, the discharge flow could be 600 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, TSS, oil and grease, cadmium, thallium, selenium, flow, mercury, and sulfate. Hatfield’s Ferry has limits for cadmium, thallium, selenium, total suspended solids ( TSS ) , and sulfate.Draft Hatfield’s Ferry Site Visi t Notes Tabl e 1 . 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 Lingenfell er 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