# Allegheny Energy
R. Paul Smith Station Williamsport, MD

Prepared for 

# Lockheed Martin

2890 Woodridge Ave #209 Edison, New Jersey 08837
April 21, 2010

CHA Project No. 20085.1020.1510 

# Assessment of Dam Safety Coal Combustion Surface Impoundments (Task 3) Final Report-iii- Final Report Assessment of Dam Safety of Coal Combustion Surface Impoundments Allegheny Energy R. Paul Smith Station Williamsport, Maryland & Falling Waters, West Virginia TABLE OF CONTENTS SECTION PAGE NUMBER
1.0 INTRODUCTION & PROJECT DESCRIPTION........................................................ 1 1.1 Introduction............................................................................................................. 1 1.2 Project Background................................................................................................. 2 1.2.1 State Issued Permits ................................................................................................ 2 1.3 Site Description and Location................................................................................. 2 1.3.1 Ash Pond #3............................................................................................................ 3 1.3.2 Ash Pond #4............................................................................................................ 4 1.3.3 Other Impoundments .............................................................................................. 4 1.4 Previously Identified Safety Issues......................................................................... 4 1.5 Site Geology............................................................................................................ 5 1.6 Bibliography ........................................................................................................... 5
2.0 FIELD ASSESSMENT................................................................................................... 13 2.1 Visual Observations.............................................................................................. 13 2.2 Visual Observations – Ash Pond #3 ..................................................................... 14 2.2.1 Ash Pond #3 – Embankments and Crest............................................................... 14 2.2.2 Ash Pond #3 – Outlet Control Structure............................................................... 15 2.3 Visual Observations – Ash Pond #4 ..................................................................... 16 2.3.1 Ash Pond #4 – Embankments and Crest............................................................... 16 2.3.2 Ash Pond #4 – Outlet Control Structure............................................................... 18 2.4 Monitoring Instrumentation.................................................................................. 18
3.0 DATA EVALUATION ................................................................................................... 46 3.1 Design Assumptions ............................................................................................. 46 3.2 Hydrologic and Hydraulic Design ........................................................................ 46 3.2.1 Ash Pond #3 – Hydrologic and Hydraulic Design................................................ 46 3.2.2 Ash Pond #4 – Hydrologic and Hydraulic Design................................................ 47 3.2.3 Flooding from the Potomac River......................................................................... 47 3.3 Structural Adequacy & Stability........................................................................... 49 3.3.1 Ash Pond #3 – Structural Adequacy & Stability .................................................. 49 3.3.2 Ash Pond #4 – Structural Adequacy & Stability .................................................. 52 3.3.3 Instrumentation Review Relative to Stability....................................................... 53 3.4 Operations, Maintenance, and Inspections ........................................................... 54 3.4.1 Inspection Procedures ........................................................................................... 54 3.4.2 Inspections by West Virginia Dam Safety............................................................ 55 3.4.3 Maintenance.......................................................................................................... 55 3.5 Foundation Conditions.......................................................................................... 56
4.0 CONCLUSIONS/RECOMMENDATIONS ................................................................. 67 4.1 Acknowledgement of Management Unit Condition............................................. 67 4.2 Upstream Slopes ................................................................................................... 67-iv- Final Report Assessment of Dam Safety of Coal Combustion Surface Impoundments Allegheny Energy R. Paul Smith Station Williamsport, Maryland & Falling Waters, West Virginia TABLE OF CONTENTS - continued SECTION PAGE NUMBER 4.3 Downstream Slopes on Ash Pond #4.................................................................... 68 4.4 Tree Removal on Ash Pond #3 Buttress............................................................... 68 4.5 Monitoring Instrumentation.................................................................................. 69 4.6 Evaluation of Conditions from Potomac River Flooding ..................................... 69
5.0 CLOSING .................................................................................................................... .... 70

TABLES Table 1 - Approximate Precipita tion Prior to Site Visit ............................................................... 13 Table 2 - Ash Pond #3 Soil Parameters Used in Stability Analyses............................................. 50 Table 3 - Ash Pond #3 Engineering Comparison to Design Criteria............................................ 50 Table 4 - Ash Pond #4 Soil Parameters Used in Stability Analyses............................................. 52 Table 5 - Ash Pond #4 Engineering Comparison to Design Criteria............................................ 53

LIST OF FIGURES Figure 1- Project Location Map...................................................................................................... 7 Figure 2 - Photo Site Plan ..................................................................................................... .......... 8 Figure 3 - Critical Infrastructure Map......................................................................................... .... 9 Figure 4A - Typical Cross Sec tion Ash Pond #3 North Dike....................................................... 10 Figure 4B - Typical Cross S ection Ash pond #3 East Dike.......................................................... 11 Figure 5 - Typical Cross Section Ash Pond #4............................................................................. 12 Figure 6A - Photo Location Plan Ash Pond #3............................................................................. 19 Figure 6B - Photo Location Plan Ash Pond #4............................................................................. 20 Figure 7A - Stability Analyses Ash Pond #3................................................................................ 57 Figure 7B - Stability Analyses Ash Pond #3 Dam ....................................................................... 58 Figure 8A - Stability Analyses Ash Pond #4................................................................................ 59 Figure 8B - Stability Analyses Ash Pond #4 ................................................................................ 60 Figure 8C - Stability Analyses Ash Pond #4 ................................................................................ 61 Figure 8D - Stability Analyses Ash Pond #4................................................................................ 62 Figure 8E - Stability Analyses Ash Pond #4 ................................................................................ 63 Figure 8F - Stability Analyses Ash Pond #4................................................................................. 64 Figure 8G - Stability Analyses Ash Pond #4................................................................................ 65 Figure 8H - Stability Analyses Ash Pond #4................................................................................ 66

APPENDIX Appendix A - Completed EPA Co al Combustion Dam Inspection Checklist Forms & Completed EPA Coal Combustion Waste (CCW) Impoundment Inspection Forms-1- Final Report Assessment of Dam Safety of Coal Combustion Surface Impoundments Allegheny Energy R. Paul Smith Station Williamsport, Maryland & Falling Waters, West Virginia 1.0 INTRODUCTION & PROJECT DESCRIPTION

1.1 Introduction

CHA was contracted by Lockheed Martin (a c ontractor to the United States Environmental Protection Agency) to perform site assessments of select ed coal combustion surface impoundments (Project #0-381 Coal Combustion Surface Impound ments/Dam Safety Inspections). As part of this contract, C HA was assigned to perform a site assessment of Allegheny Energy’s Ash Pond #3 and Ash Pond #4 at the R. Paul Smith Power Station. The
Power Station is located in W illiamsport, Maryland, and the ash lagoons are in Falling Waters, West Virginia as shown on Figure 1 – Project Location Map.

CHA made a site visit on October 20, 2009 to inventory coal combustion surface impoundments at the facility, perform visual observations of the containment dikes, and collect relevant information regarding the site assessment.

CHA Engineers Katherine Adnams, P.E., and Khalid Abed, P.E. were accompanied by the following individuals:

Company or Organization Name and Title Allegheny Energy Gary Haag, Environmental Manager Allegheny Energy Erik Johnsson, Engineer Allegheny Energy Mark Vindivich, Manager Production
GAI Consultants Barry Newman, PE, Vice President – Geotechnical and Structural Engineering-2- Final Report Assessment of Dam Safety of Coal Combustion Surface Impoundments Allegheny Energy R. Paul Smith Station Williamsport, Maryland & Falling Waters, West Virginia 1.2 Project Background

Ash Ponds #3 and #4 are under the jurisdiction of the State of West Virginia Department of Environmental Protection (WVDEP). According to the West Virginia Title 47 Legislative Rule, Series 34 Dam Safety Rule, the dikes for thes e impoundments have a Hazard Classification of Class 2 (Significant Hazard) meaning the fail ure of the dam may cause minor damage to dwellings, commercial or industrial buildings, importa nt public utilities, ma in railroads, or cause major damage to unoccupied buildings, or wher e a low risk highway may be affected or damaged. The potential for loss of human life resulting from failure must be unlikely.

1.2.1 State Issued Permits

Ash Ponds #3 and #4 were constructed prior to WVDEP requiring Certif icates of Approval, which became a requirement in 1992. Allegheny Energy received a Certif icate of Approval for
Ash Pond #3 in 1996 and another in 1999 fo r repair to the outlet works.

Allegheny Energy received an initial Certificat e of Approval for work at Ash Pond #4 in 1981, and another in 1997 for repair to the outlet works.

A National Pollutant Discharge Eliminati on System (NPDES) permit, MD0000582 has been issued to Allegheny Energy authorizing discharg e to the Potomac River in accordance with effluent limitations, monitoring requirements and other conditions set forth in the permit. The permit became effective on August 16, 2008 and is set to expire on July 16, 2013.

1.3 Site Description and Location

Ash Ponds #3 and #4 (also referred to in some documents as Lagoons #3 and #4) are located on
the west bank of the Potomac Ri ver in Falling Waters, West Virg inia. Pond #3 is located to the north of Pond #4. Figure 2 shows a site plan, an d Figures 3 and 4 shows a typical cross section-3- Final Report Assessment of Dam Safety of Coal Combustion Surface Impoundments Allegheny Energy R. Paul Smith Station Williamsport, Maryland & Falling Waters, West Virginia of the dams. Allegheny Energy al ternates use of the ponds, pumping to one until it is full, and then switching to the other while the full impou ndment is dewatered an d dredged with the ash taken to a nearby landfill.

A map of the region indicating the location of th e R. Paul Smith Power Station and Ash Ponds #3 and #4 identifying sc hools, hospitals, or other critical infrastructure located within approximately five miles down gradient of the ash pond is provided as Figure 3. The community of Falling Waters, West Virginia is a bout 5 miles downstream from the dam.

1.3.1 Ash Pond #3

Ash Pond #3 is impounded on three sides (north, east, and south) by an earthen embankment dike. The west side is impounded by natura l topography. The Ash Pond #3 dikes have a maximum height of approximately 46 feet resu lting in a maximum storage capacity of 104 acrefeet. The east dike is buttre ssed with rock fill, while the north and south dike sections are armored with rock fill, but not buttressed (i.e., the rock fill was not placed to contribute to the structural stability). The toe of the east dike buttress extends approximate ly to the shoreline of
the Potomac River at normal water level in the river. The water level in Lagoon #3 is controlled by an HDPE spillway riser pipe at the south end of the lagoon. Originally constructed in the 1960s (exact year unknown) this impoundment ha s been modified several times; in 1980 the
crest of the dike was raised after flooding of the Potomac Rive r related to Hurricane Agnes (1972) came near the dam crest elevation, and in 1999 the corrugated metal pipe (CMP) outlet corroded through and caused increas ed flow through the discharge. Repair work was performed
in 1999 without release of CCW. Figures 4A and 4B show typi cal cross sections of the Ash
Pond #3 dikes.-4- Final Report Assessment of Dam Safety of Coal Combustion Surface Impoundments Allegheny Energy R. Paul Smith Station Williamsport, Maryland & Falling Waters, West Virginia 1.3.2 Ash Pond #4

Ash Pond #4 is impounded on three sides (north, east, and south) by an em bankment dike. The west side is impounded by natura l topography. The Potomac River lies approximately 70 to 100 feet east of the lagoon. The Ash Pond #4 dikes have a maximum height of approximately 41 feet resulting in a maximum storage capacity of 218 acre-feet. The dikes have downstream slopes of about 2H:1V, and upstream slopes of about 1.7H to 2H:1V. The ups tream slope is partially lined with a hypalon geosynthetic liner. The downstrea m slope is grasses and weedy vegetation. The water level in Ash Pond #4 is controlled by an HDP E spillway riser pipe at the south end of the spillway. Originally constructed in the early 1960s (exact year unknown) this impoundment had repairs performed in 1997 on the spillway outle t pipe after corrosion through the CMP outlet pipe resulted in increased flows dischargin g from the pond. Figure 5 shows a typical cross
section of the Ash Pond #4 dikes.

1.3.3 Other Impoundments

There were no other impoundments observed at th e R. Paul Smith Power Station Site. CHA inquired as to whether Ponds #1 and #2 existed, and Allegheny Energy responded that these were formerly in Maryland at the physical plant site and that they were retired in the 1960s. Pond #1 was removed and Pond #2 was filled with soil and grass covered.

1.4 Previously Identified Safety Issues

In 1997 and 1999, failures of the original CMP ou tlet pipes occurred in Ash Pond #4 and Ash Pond #3, respectively. Routine obs ervations by plant personnel found increased flows from the outlet pipes, which suggested failure within the outlet structure. During each situation, Allegheny Energy hired an outside consultant to investigate where the failure had occurred and develop repairs to be implemented. In both cases, the riser struct ure was replaced with a 42-inch-5- Final Report Assessment of Dam Safety of Coal Combustion Surface Impoundments Allegheny Energy R. Paul Smith Station Williamsport, Maryland & Falling Waters, West Virginia diameter HDPE riser, and the 18-inch CMP pipes were slip lined with 14-inch HDPE pipes with the annulus between CMP and HDPE grouted.

Based on our review of the information provide d to CHA and as reported by Allegheny Energy,
there have been no additional safe ty issues identified at Ponds #3 and #4 in the last 10 years.

1.5 Site Geology

According to U.S. Geological Survey Open-File Report 01-188 , Geology of the Chesapeake and
Ohio Canal National Historical Park and Poto mac River Corridor, District of Columbia, Maryland, West Virg inia, and Virginia, the geology of the area of Ponds #3 and #4 is likely shale, siltstone and sandstone bedrock with possibl e layers of limestone within the Great Valley geologic region. This region is likely part of the Martinsburg formation which is surrounded by other geologic formations of limestone and dolom ite formations that include abundant caves and sinkholes. The bedrock is overlain by Holocene a nd Pleistocene era terraces of sand, gravel and boulders, and Holocene era alluvium consisting of unconsolidated clay, silt, sand and gravel underlying modern era floodplains.

CHA observed road signs in Falling Waters, West Virginia indicating that sinkholes due to karst topography were common, but did not see evidence of such features at the Ash Pond sites.

1.6 Bibliography

CHA reviewed the following documents pr ovided by WVDEP and Allegheny Energy in preparing this report:

 R. Paul Smith Power Station, Lagoon/Dam No. 3, letter from GAI Consultants, March 13, 2009.-6- Final Report Assessment of Dam Safety of Coal Combustion Surface Impoundments Allegheny Energy R. Paul Smith Station Williamsport, Maryland & Falling Waters, West Virginia  Results of Supplemental Stability Analys es, Wastewater Treatment/Ash Storage Lagoon/Dam No. 4 , GAI Consultants, October 2009.

 Order of Compliance, issued by West Virginia Departme nt of Environmental Protection, January 30, 2009.

 Modification to Certificate of Approval – Outlet Works Reconstruction, Lagoon No. 4, SE Technologies, September 1997.

 Outlet Works Reconstruction Wast ewater/Ash Storage Lagoon No. 3, GAI Consultants, January 1999.

 WVDEP Inspection Reports for R. Paul Smith Power Station Lagoons #3 and #4, WVDEP 2009, 2006.

 Biannual Independent Consultant Inspection Report – R. Paul Smith Power Station Lagoons #3 and #4, Various consultants
, 2004, 2006, 2008, 2009.

 Dam Safety Maintenance Plans for Wastew ater/Ash Storage Lagoons No. 3 and No.4, Allegheny Energy, May 2006.

### Figure 1 Project Location Map

Allegheny Energy R. Paul Smith Station

Williamsport, MD Scale: 1" = 1 mile Project No.: 20085.1020.1510 

### R. Paul Smith Station

IMAGE DATE: 07/01/1981ASH POND #3 R. PAUL SMITH STATION

ALLEGHENY ENERGY LANDFILL ASH POND #4 POTOMAC RIVER SMALTZ DRR. PAUL SMITH STATION
ASH POND #3

ASH POND #4 POTOMAC RIVER

FLOWORIGINAL DOWNSTREAM SLOPE-13- Final Report Assessment of Dam Safety of Coal Combustion Surface Impoundments Allegheny Energy R. Paul Smith Station Williamsport, Maryland & Falling Waters, West Virginia 2.0 FIELD ASSESSMENT

2.1 Visual Observations

CHA performed visual observations of Ash Pond s #3 and #4 following the general procedures
and considerations containe d in Federal Emergency Mana gement Agency’s (FEMA’s) Federal Guidelines for Dam Safety (April 2004), and Federal Ener gy Regulatory Commission (FERC) Part 12 Subpart D to make observations concer ning settlement, movement, erosion, seepage, leakage, cracking, and deteriora tion. A Coal Combustion Dam Inspection Checklist and Coal Combustion Waste (CCW) Impoundment Inspection Form, prepared by the US Environmental Protection Agency, were completed on-site during the site visit. Copies of the completed forms
were submitted via email to a Lockheed Mart in representative approximately three days following the site visit to the R. Paul Smith Powe r Station. Copies of these completed forms are included in Appendix A. Photo lo gs and Site Photo Location Plan (Figures 6A and 6B) for Ash
Ponds #3 and #4 are located at the end of Section 2.4.

CHA’s visual observations were made on October 20, 2009. The weather was sunny with temperatures between 40 and 70 degrees Fahrenhe it. Prior to the days we made our visual observations, the following approximate rainfall amounts occurred (as reported by
www.weather.com ).

Table 1– Approximate Precipita tion Prior to Site Visit Date of Site Visit – October 20, 2009 Day Date Precipitation (inches) Monday October 13, 2009 Trace Tuesday October 14, 2009 0.00 Wednesday October 15, 2009 0.56

Thursday October 16, 2009 0.15

Friday October 17, 2009 0.45 Saturday October 18, 2009 0.06 Sunday October 19, 2009 0.00

Total Week Prior to Site Visit 1.22 Total 30 Days Prior to Site Visit 1.80-14- Final Report Assessment of Dam Safety of Coal Combustion Surface Impoundments Allegheny Energy R. Paul Smith Station Williamsport, Maryland & Falling Waters, West Virginia 2.2 Visual Observations – Ash Pond #3

CHA performed visual observations of Ash Pond #3. Ash Pond #3 is about 1,700 feet long with a maximum height of 46 feet. The pond is impounded by dikes on the north, east and south sides, and by natural ground on the west side.

2.2.1 Ash Pond #3 – Embankments and Crest

In general, the alignments of the crest of As h Pond #3 dikes do not show signs of change in horizontal alignment. The crest is typically about 12 feet wide and is grass covered as shown in Photos 2, 6, and 15. The cr est is slightly wider at the west e nd of the north dike because of ash left against the upstream slope during past dredging operations.

The upstream slope is grass c overed to the elevation corres ponding to maximum storage, and exposed ash below that elevation due to recent 2008 dredging operations. The upstream slope of
the north dike is shown in Phot o 4, the upstream slope of the east dike is shown in Photo 7, and the upstream slope of the south dike is shown in Photos 16 and 17. The north end of the east dike was over excavated to an overly steep slop e during recent dredging operations. This over excavation during dredging operations appears, from reports review ed, to occur frequently. The 2009 GAI report notes that this condition was di scussed in a 1978 and 1995 stability reports. Non-disturbed slopes are about 3H:1V. A benc h remains in the south east corner of the pond adjacent to the outlet structure. This bench is a remnant of access ramps constructed to perform upgrades to the outlet structure in 1999. The upstream slope between the top of the ramp and the crest of the dike is qu ite steep, with contours on a May 2009 survey showing the slope at about
1.3 to 1.4 horizontal to 1 vertic al. The remaining portions of th e south dike upstream slope are
about 2.5H:1V.-15- Final Report Assessment of Dam Safety of Coal Combustion Surface Impoundments Allegheny Energy R. Paul Smith Station Williamsport, Maryland & Falling Waters, West Virginia The downstream slope is armored with rip rap gene rally about 6 to 8 inches in diameter. The east dike is buttressed with an approximately 20- to 25-foot wide stone bench which then slopes
to the shore of the Potomac River. Access to th e downstream slope of the buttress is hindered by tree growth and the proximity to the river, with some sections of the buttress extending to the water line, while in other areas there was a na rrow strip of shoreline beyond the toe of slope. Photo 5 shows the downstream slope of the north dike, Photos 8, 11 and 12 show the downstream slope of the east dike, Photos 9, 10 a nd 14 show the east dike buttress, and Photos 18, 19 and 20 show the downstream slope of the south dike. In general the dike slope was free of vegetation, although areas of grass had established along the south dike.

An area of possible seepage has been noted and obs erved in past inspection reports about 35 feet from the toe of the south dike near the outlet pipe discharge point. This area is shown in Photos 21 and 22. CHA did not observe flow or depos ition of sediment in the seepage area, and Allegheny Energy indicated that it is likely related to natural drainage betw een Ponds #3 and #4, but that they had not definitively determined this so they continue to make observations as if it were seepage. The ground surface in this seepage ar ea is about 4 feet be low the elevation of standing water in the recently dredged pond that was observed in the pond during CHA’s visit.

2.2.2 Ash Pond #3 – Outlet Control Structure

Ash Pond #3 discharges through an HDPE decant st ructure with multiple ports in the riser as
shown in Photo 16. As the water/ash level rises when the pond is in service, Allegheny Energy personnel install blind flanges when they are ready to raise the level to the next port. This riser discharges below the south dike via a 14-inch HDPE which was sliplined into the original 18- inch CMP pipe. The discharge e nd of the pipe is shown in Photo 23. It discharges into a
Fabriform® lined channel which discharges to the Potomac River as shown in Photo 24.-16- Final Report Assessment of Dam Safety of Coal Combustion Surface Impoundments Allegheny Energy R. Paul Smith Station Williamsport, Maryland & Falling Waters, West Virginia 2.3 Visual Observations – Ash Pond #4

Ash Pond #4 is about 2,020 feet long with a ma ximum height of 41 feet. The pond is impounded by dikes on the north, east and south sides, and by natural ground on the west side.

2.3.1 Ash Pond #4 – Embankments and Crest

In general, the alignments of the crest of As h Pond #4 dikes do not show signs of change in horizontal alignment. The crest is about 10 feet wide and is grass covered as shown in Photos 27, 33, 34 and 42. The surface has moderate rutting from vehicle traffic on the crest. An approximately 14-inch diameter, 2-inch deep de pression was observed on the crest in the area where the discharge pipe passes beneath the east dike. The discharge pi pe was slip-lined in 1997, as described in Section 1.3.2.

The upstream slope at the east end of the north a nd south dikes, and the entire length of the east
dike is lined with a hypalon liner as shown in Photos 29, 33, and 43. Reports reviewed by CHA
indicated this liner was installe d in 1981 to control the phreatic surface within the embankment to maintain adequate slope stability. Alleghe ny Energy maintains the li ner, routinely patching small holes made by animals walking on the liner as shown in Photo 30. Th e western ends of the
north and south dike are covered with weedy vegetation, which had been freshly cut prior to our site visit. The surface of vege tated upstream slope on the north di ke was soft to about 18 inches and irregularly graded. Allegheny Energy indicated that some of the soft material was likely ash left after various dredging operations that became weed covered. This slope is shown in Photos 27 and 28. The vegetated portion of the upstream sl ope on the south dike is steep and Allegheny Energy indicated that this slope will be regraded and buttressed as part of upcoming work to be performed when the pond is next taken out of serv ice (i.e., when they switch to sluicing ash into Pond #3).-17- Final Report Assessment of Dam Safety of Coal Combustion Surface Impoundments Allegheny Energy R. Paul Smith Station Williamsport, Maryland & Falling Waters, West Virginia The downstream slopes are weed covered which was freshly cut at the time of our site visit. Photo Nos. 31, 35, and 46 show the general cond ition of the downstream slope. Many features
of deterioration of the downstream slopes were noted as listed below:

• Several areas of surface erosion and sloughing we re observed. Near the northeast corner,
surface erosion has occurred at the fence line as shown in Photo 36. This feature was noted in previous inspection reports and according to Allegheny Energy personnel, has remained unchanged in many years. A sim ilar area of surface erosion was noted near location marking tag #30. Between mark ing tags #56 and #57, a clump of woody vegetation stumps appeared to be inhibiting sheet flow along the slope surface but rather forcing erosion rills to develop around it.

• A bench with a top elevation about 2 feet lowe r than the crest that is located near the middle portion of the east dike appeared to have a surface slump with bulging and steepening of the toe. This feature wa s located near locatio n marking tag #48.

• In general the surface soils on the east downs tream slope were soft, and shifted when walked on. Significant rain had been receive d in the week preceding our site visit and Allegheny Energy personnel indicated that some of the surface sloughing such as that shown in Photo 38 may have occurred while contractor crews were weed-whacking the slope.

• The natural slope between the toe of the Ash Pond #4 dike and the Potomac River is covered with trees. For the most part, these tr ees start at the toe of the dike. However, in a few locations, such as that shown in Photo 37, large trees are actually within the toe of the east dike. Low hanging branches from these trees beyond the to e of the dike are encroaching on the dike as shown in Photo 40. Small shrubs were observed on the south
dike as shown in Photo 47.

• Filled in rodent holes were observed on the downstream slopes as shown in Photo 39. Allegheny Energy described burro wing rodents as an ongoing problem at this site, and that they routinely fill rodent burrows as found, and each spring perform rodent control-18- Final Report Assessment of Dam Safety of Coal Combustion Surface Impoundments Allegheny Energy R. Paul Smith Station Williamsport, Maryland & Falling Waters, West Virginia finding that performing removal of the an imals around mating season has had a positive impact on gaining control on the rodent population.

CHA did not observe seepage and the drainage swale at an appa rent toe drain along the south dike was dry. CHA also took a re ading in a piezometer at about the mid point of the east dike,
which indicated water in the dike was between 28 and 30 feet below the crest surface. The dike in this area is about 22 feet high. Alleghe ny Energy’s consultant, GAI Consultants, indicated that they had found similar piezo meter readings during a 2009 review of the stability of the Ash Pond #4 dike, which is more thorou ghly discussed in Section 3.3.2.

2.3.2 Ash Pond #4 – Outlet Control Structure

Ash Pond #4 discharges through an HDPE riser in the southeast corner of the pond as seen in Photo 48. Allegheny Energy indicate d this structure was the same as the one observed in Ash
Pond #3. At the time of CHA’s site visit the water level in Ash Pond #4 was at the top crest of
the decant structure. The decant structure disc harges beneath the east dike through a 14-inch diameter HDPE sliplined into the original CMP pipe as describe d in Section 1.3.2. The discharge end of the pipe is seen in Photo 49 and discha rges into a rip rap lined channel to the
Potomac River as shown in Photo 50.

2.4 Monitoring Instrumentation

There are a few piezometers on the Ash Pond #4 di kes. These piezometers were installed in 1997 as part of the outlet riser re pair project, and have not been monitored until 2009 when they were used by GAI to determine the phreatic surf ace in the dam for stability analyses to meet requirements of a WVDEP Order of Compliance issu ed in the wake of the TVA Kingston event. There is no monitoring instrume ntation on Ash Pond #3 dikes.1

2

3

7

4 5

6

12 13 14

10 8

9 17 16

11 15 24 23 20 21, 22 19 1846

45

44

47

43 42 41 48

37

49

50 34

35 40 36 33 29 31 32 27 26 25 28Page 21 Pond #3, looking southeast from the north abutment. West side of pond (right side of photo) is in natural ground.

Crest of north dike at Pond #3, looking east.

ALLEGHENY ENERGY R. PAUL SMITH STATION POND #3 WILLIAMSPORT, MD
CHA Project No.: 20085.1020.1510 October 20, 2009 1

2Page 22 Upstream slope of north dike at Pond #3, looking east. Irregularity of slope related to remain ing ash from recent dr edging operations.

Upstream slope of north dike at Pond #3, looking west. Pond was dredged in 2008.

ALLEGHENY ENERGY R. PAUL SMITH STATION POND #3 WILLIAMSPORT, MD
CHA Project No.: 20085.1020.1510 October 20, 2009 3

4Page 23 Downstream slope of north dike at Pond #3, looking west towards north abutment.

Crest of east dike at Pond #3, looking south

ALLEGHENY ENERGY R. PAUL SMITH STATION POND #3 WILLIAMSPORT, MD
CHA Project No.: 20085.1020.1510 October 20, 2009 5

6Page 24 Upstream slope of east dike at Pond #3, looking south. Irregularity in

slope related to over excavation du ring recent dredging operations.

Downstream slope of east dike at Pond #3 looking north.

ALLEGHENY ENERGY R. PAUL SMITH STATION POND #3 WILLIAMSPORT, MD
CHA Project No.: 20085.1020.1510 October 20, 2009 7

8Page 25 Trees growing in stone buttress on east dike of Pond #3, looking north.

Stone buttress on east dike of Pond #3 extends to the edge of the Potomac River.

ALLEGHENY ENERGY R. PAUL SMITH STATION POND #3 WILLIAMSPORT, MD
CHA Project No.: 20085.1020.1510 October 20, 2009 9

10Page 26 Downstream slope of east dike at Pond #3, looking north.

Sluice lines from R. Paul Smith Station at northeast corner of Pond #3 service both Pond #3 and Pond #4. Hardened steel lines to dike crest an d they are replaced approximately ever y 15 years as routine maintenance.

ALLEGHENY ENERGY R. PAUL SMITH STATION POND #3 WILLIAMSPORT, MD
CHA Project No.: 20085.1020.1510 October 20, 2009 11

12Page 27 Slice lines from R. Paul Smith Station traverse the Potomac River are hardened steel and protected with rip rap. The sluice lines are replaced approximately every 15 years as routine maintenance.

Stone buttress looking south from northeast corner of Pond #3.

ALLEGHENY ENERGY R. PAUL SMITH STATION POND #3 WILLIAMSPORT, MD
CHA Project No.: 20085.1020.1510 October 20, 2009 13

14Page 28 Crest of south dike at Pond #3, looking west toward south abutment.

Upstream slope of south dike of Pond #3 looking south and decant structure. Bench is remnant of an access road built when the decant structure was replaced in 1997.

ALLEGHENY ENERGY R. PAUL SMITH STATION POND #3 WILLIAMSPORT, MD
CHA Project No.: 20085.1020.1510 October 20, 2009 15

16Page 29 Upstream slope of south dike of Pond #3 looking southwest. South abutment at right of photo.

Downstream slope of south dike of Pond #3, looking east.

ALLEGHENY ENERGY R. PAUL SMITH STATION POND #3 WILLIAMSPORT, MD
CHA Project No.: 20085.1020.1510 October 20, 2009 17

18Page 30 Downstream slope of south dike of Pond #3, looking east.

Typical patchy vegetation on rip rap ar mor of downstream slopes of Pond #3. Mostly grasses, occasional saplings.

ALLEGHENY ENERGY R. PAUL SMITH STATION POND #3 WILLIAMSPORT, MD
CHA Project No.: 20085.1020.1510 October 20, 2009 19

20Page 31 Possible (and previously noted) seepage area south of south dike of Pond #3 looking north. Possibly related to natural drainage between Ponds #3 and #4.

Close up of possible seepage area. No obvious flow and no observed deposition of sediment.

ALLEGHENY ENERGY R. PAUL SMITH STATION POND #3 WILLIAMSPORT, MD
CHA Project No.: 20085.1020.1510 October 20, 2009 21

22Page 32 Outlet pipe from the decant structure. Pond currently dewatered/dredged below the decant elevation.

Fabriform lined discharge channel from Pond #3 to the Potomac River.

ALLEGHENY ENERGY R. PAUL SMITH STATION POND #3 WILLIAMSPORT, MD CHA Project No.: 20085.1020.1510 October 20, 2009 23

24Page 33 West side of Pond #4 is in natural ground, looking south.

Pond #4, looking southeast.

ALLEGHENY ENERGY R. PAUL SMITH STATION POND #4 WILLIAMSPORT, MD
CHA Project No.: 20085.1020.1510 October 20, 2009 25

26Page 34 Crest of the north dike at Pond #4, looking east.

Upstream slope of north dike at Pond #4, looking northeast.

ALLEGHENY ENERGY R. PAUL SMITH STATION POND #4 WILLIAMSPORT, MD
CHA Project No.: 20085.1020.1510 October 20, 2009 27

28Page 35 Hypalon liner on the upstream slope of the north dike at Pond #4.

Routine maintenance includes patching holes on the hypa lon liner created by animals walking on the liner.

ALLEGHENY ENERGY R. PAUL SMITH STATION POND #4 WILLIAMSPORT, MD
CHA Project No.: 20085.1020.1510 October 20, 2009 29

30Page 36 Downstream slope of north dike at Pond #4, looking north.

Sluice lines at north abutment.

ALLEGHENY ENERGY R. PAUL SMITH STATION POND #4 WILLIAMSPORT, MD
CHA Project No.: 20085.1020.1510 October 20, 2009 31

32Page 37 Crest of east dike at Pond #4, looking south.

Crest of east dike at Pond #4, looking south.

ALLEGHENY ENERGY R. PAUL SMITH STATION POND #4 WILLIAMSPORT, MD
CHA Project No.: 20085.1020.1510 October 20, 2009 33

34Page 38 Downstream slope of east dike at Pond #4, looking south.

Surface erosion at downstream slope/c rest on east dike at Pond #4. This erosion has been noted in previous inspection reports and has not changed in many years.

ALLEGHENY ENERGY R. PAUL SMITH STATION POND #4 WILLIAMSPORT, MD
CHA Project No.: 20085.1020.1510 October 20, 2009 35

36Page 39 Large tree at toe of east dike sl ope at Pond #4, looking north.

Erosion/surficial sloughing on east di ke at Pond #4. Surface soil soft.

ALLEGHENY ENERGY R. PAUL SMITH STATION POND #4 WILLIAMSPORT, MD
CHA Project No.: 20085.1020.1510 October 20, 2009 37

38Page 40 Filled in rodent holes on east dike at Pond #4. Rodent control is performed each spring and observed holes are filled as part of routine maintenance of the dikes.

Adjacent tree branches near ea st dike slope at Pond #4.

ALLEGHENY ENERGY R. PAUL SMITH STATION POND #4 WILLIAMSPORT, MD
CHA Project No.: 20085.1020.1510 October 20, 2009 39

40Page 41 Depression about 2 inches deep and 18 inches in diameter on crest of east dike in approximate area of outlet pipe.

Crest at southeast co rner of Pond #4.

ALLEGHENY ENERGY R. PAUL SMITH STATION POND #4 WILLIAMSPORT, MD
CHA Project No.: 20085.1020.1510 October 20, 2009 41

42Page 42 Upstream slope of south dike at Pond #4, looking southwest.

Upstream slope of south dike at Pond #4, looking east.

ALLEGHENY ENERGY R. PAUL SMITH STATION POND #4 WILLIAMSPORT, MD
CHA Project No.: 20085.1020.1510 October 20, 2009 43

44Page 43 Upstream slope of the south dike at Pond #4, looking west toward the south abutment.

Downstream slope of the south dike at Pond #4, looking east.

ALLEGHENY ENERGY R. PAUL SMITH STATION POND #4 WILLIAMSPORT, MD
CHA Project No.: 20085.1020.1510 October 20, 2009 45

46Page 44 Small trees on downstream slope on south dike at Pond #4, looking east.

Decant structure in the sout heast corner of Pond #4.

ALLEGHENY ENERGY R. PAUL SMITH STATION POND #4 WILLIAMSPORT, MD
CHA Project No.: 20085.1020.1510 October 20, 2009 47

48Page 45 Discharge pipe from Pond #4.

Rip rap channel from the Pond #4 outlet to the Potomac River.

ALLEGHENY ENERGY R. PAUL SMITH STATION POND #4 WILLIAMSPORT, MD CHA Project No.: 20085.1020.1510 October 20, 2009 49

50- 46- Final Report Assessment of Dam Safety of Coal Combustion Surface Impoundments Allegheny Energy R. Paul Smith Station Williamsport, Maryland & Falling Waters, West Virginia 3.0 DATA EVALUATION

3.1 Design Assumptions

CHA has reviewed the desi gn assumptions related to the design and analysis of the stability and hydraulic adequacy of the Ash Ponds #3 and #4, wh ich were available at the time of our site visits and provided to us by A llegheny Energy. The design assumptions are listed in the following sections.

3.2 Hydrologic and Hydraulic Design

Dams in West Virginia are governed by West Vi rginia Rule 47CSR34. Under this legislation the
Ash Ponds #3 and #4 are classified as Class 2, significant hazar d, dams. This classification requires the dam to safely pass or store the inflow from 50 percent of the 6-hour duration Probable Maximum Precipitation (PMP), discharg e 90% of the stored storm volume within 10 days after the storm event, and emergency spillw ay operation frequency shall be no more than once in 50 years, if included. Ash Ponds #3 a nd #4 were constructed with only primary drop inlet type spillways and do not have emergency sp illways. In this case the West Virginia regulations require that the impound ment have adequate storage to contain the full inflow from the design storm (i.e., assumes the outlet becomes clogged during a storm event).

3.2.1 Ash Pond #3 – Hydrologic and Hydraulic Design

CHA reviewed hydrologic and hydraulic analyses performed by GAI Consultants in 1999 when the spillway was repaired. These analyses sugg est that 50 percent of the PMP at the R Paul Smith site is 14 inches, and the drainage area is about 64 acres. When accounting for infiltration within the watershed, the resul ting volume of inflow to Ash Pond #3 was determined by GAI to-47- Final Report Assessment of Dam Safety of Coal Combustion Surface Impoundments Allegheny Energy R. Paul Smith Station Williamsport, Maryland & Falling Waters, West Virginia be 37.4 acre-feet. From a maximum operating pool of El. 373, the resulting peak water surface
elevation is 377.5.

3.2.2 Ash Pond #4 – Hydrologic and Hydraulic Design

CHA reviewed hydrologic and hydraulic analyses performed by SE Technologies, Inc. in 1997 when the spillway was repaired. These analyses used 50 percent of the PMP reported to be 13.75 inches, and a drainage area of about 74 acr es. The maximum reported elevation in Ash Pond #4 was determined to be El. 372.9 with discharge through the spillway. The outflow hydrograph ordinates were includ ed in the report, so CHA evaluated the volume which this analysis assumed would discharge from the pond and determined that during the storm event, approximately 6.1 acre-feet had been estimated to drain from the pond. From the elevationvolume rating curve included in th e SE Technologies report, CHA de termined that even without outflow from the outlet structure, the design stor m will be stored within the pond. With outflow the peak water surface eleva tion will be about El. 372.9, and w ithout outflow the peak water surface elevation will be slightly below El . 375 with the top of the dikes at El. 378.

3.2.3 Flooding from the Potomac River

The Potomac River is suscepti ble to flooding. The highest r ecorded flooding occurred in 1936
when the River rose to El. 377.6 at the ash ponds. In 1972, runoff from Hurricane Agnes reportedly resulted in peak river flows in the area of Ash Ponds #3 and #4 of approximately El. 365. Having been inactive for several years, prio r to return to service, in 1980, the rock buttress
was added to the Pond #3 east dike and the crest of the dikes were raised to El. 380. The crest of
Pond #4 is at El. 378.-48- Final Report Assessment of Dam Safety of Coal Combustion Surface Impoundments Allegheny Energy R. Paul Smith Station Williamsport, Maryland & Falling Waters, West Virginia CHA reviewed data readily available on the intern et on historic flooding in the Potomac River at Williamsport, Maryland and Falling Waters, West Virginia. Available references from USGS
and FEMA indicate:

• 100-yr flood elevation is estimated on FIRM ma ps to be El. 371 adjacent to the upstream end of Pond #4 and at El. 372 at the power plant dam, slightly upstream from the upstream end of Pond #3.

• Top five historic crests on Potomac betw een 1936 and present do not include Hurricane Agnes in 1972. These five events ranged fr om crest stage 34.8 to 48.6. Flood stage is reportedly at 23 feet (or approximately El. 329 based on the peak stage and elevation associated with the 1936 event). No sp ecific correlation between River stage and
elevation was found for this section of the Potomac River.

• Top five historic crests reported in Williamsport were also listed as the top five in Hancock the nearest upstream USGS gauging station. Four of the top five in Williamsport were in the top five at Shepherdstown, the nearest downstream USGS gauging station. Data available suggested th at it was possible that during a 1996 event the gage in Shepherdstown was not in servi ce. At Shepherdstown a 1985 event had about the same river stage level as Hurricane A gnes; the 1985 event at Hancock was about 5 feet lower than the rise at Hancock as a result of Hurricane Agnes.

Hurricane Agnes dropped 6.3 inches of rain on Hagerstow n, Maryland (about 6 miles to the northeast from Williamsport) between June 20 a nd 23, 1972. Reportedly, despite the rain, flood levels on the Potomac did not come close to the record floods of 1936, which resulted from a combination of heavy rain on top of heavy snow p acks. A similar rain on snow event occurred in 1996, which produced one of the top five flood ev ents in this area of the Potomac River.

Reports about the impact of Hurricane Agnes in dicated that above Hanc ock, no unusual flooding was observed and that most of the flooding o ccurred in tributaries of the Potomac River-49- Final Report Assessment of Dam Safety of Coal Combustion Surface Impoundments Allegheny Energy R. Paul Smith Station Williamsport, Maryland & Falling Waters, West Virginia downstream of the confluence with the Shena ndoah River. On tributaries between the Conococheague Creek at Fairview, Maryland, whic h joins the Potomac River in Williamsport, and the Rock Creek at Washington, DC, flooding exceeded the 100-year frequency elevations. Peak flows in some of the larger streams range d from 2 to 6 times greater than previously
recorded maximums.

Given the relatively frequent number of flooding events between 1936 and the present at Williamsport, CHA recommends quantifying the risk to Ash Ponds #3 and #4 from high waters
on the Potomac River.

3.3 Structural Adequacy & Stability

CHA has reviewed engineering reports for sl ope stability in comparison to the criteria established by West Virginia Rule 47CSR34 for Ash Ponds #3 and #4 as indicated in the following subsections.

3.3.1 Ash Pond #3 – Structural Adequacy & Stability

GAI reviewed the structural stab ility of Ash Pond #3 as part of Allegheny Energy’s response to WVDEP’s Order of Compliance foll owing the TVA Kingston incident . This review was largely performed by reviewing previous engineering reports by GAI and others dating back to 1978. The analyses were performed looking at dow nstream slopes of 2H:1V, and “as designed” upstream slopes of 3H:1V. The upstream slope was much steeper below the maximum ash disposal line during CHA’s site visit due to over excavation during 2008 dredging operations, and this type of condition was described by GAI as being noted in 1978 and 1995 as well.

The general soil profile at Ash Pond #3 consists of the homogeneous silt y clay fill embankment founded on natural silty clay overlying sand and gr avel overlying bedrock. Table 2 summarizes-50- Final Report Assessment of Dam Safety of Coal Combustion Surface Impoundments Allegheny Energy R. Paul Smith Station Williamsport, Maryland & Falling Waters, West Virginia the soil properties used in the stability analyses . The year in parentheses indicates properties used in the respective reviews of stability.

Table 2 – Ash Pond #3 Soil Parameters Used in Stability Analyses
Soil Stratum Unit Weight (pcf) Friction Angle (degrees) Cohesion (psf)
Embankment Fill 130 (‘95) 125 (‘99) 32 (’95) 28 (’99) 100 (’95) 200 (’99)
Ash 95 (’95,’99) 31 (’95,’99) 0 (’95,’99)
Proposed Shale Fill 125 (’99) 34 (’99) 400 (’99)
Rip Rap 140 (’95,’99) 40 (’95,’99) 0 (’95,’99)
Natural Silty Clay 130 (’95) 125 (‘99) 35 (’95,’99) 0 (’95,’99)

Natural Sand and Gravel 1 135 (’95) 39 (’95) 0 (’95) 1. Sand and gravel layer not included in 1999 analyses
Cross sections of the north, south and buttressed east dikes were evaluated for stability. The results of these analyses are presented in Table 3 below and graphical inte rpretation is presented in Figures 4B (Section 2), 7A and 7B.

Table 3 – Ash Pond #3 Engineering Comparison to Design Criteria Design Consideration Criteria Engineering Results North Dike East Dike South Dike Downstream Slope Steady State Conditions (1995): Pond surface @ El. 378 Potomac River @ Normal Pool 1.5 SS 1 1.2 EQ 2 1.8 SS 1.5 EQ 1.5 SS 1.3 EQ 2.0 SS 1.7 EQ
Downstream Slope Steady State Conditions (1995): Pond surface @ El. 378 Potomac River @ El. 376 -- 1.9 SS 1.5 EQ 1.9 SS 1.5 EQ 2.0 SS 1.5 EQ-51- Final Report Assessment of Dam Safety of Coal Combustion Surface Impoundments Allegheny Energy R. Paul Smith Station Williamsport, Maryland & Falling Waters, West Virginia Table 3 – Ash Pond #3 Engineering Compar ison to Design Criteria - continued Design Consideration Criteria Engineering Results North Dike East Dike South Dike Upstream Slope Steady State Conditions (1999): Pond surface @El. 372 Potomac River @ Normal Pool 1.5 2.2 2.2 2.2

Upstream Slope Steady State Conditions (1995): Pond surface @ El. 360 Potomac River @El. 376 -- 1.5 SS 1.3 EQ 1.5 SS 1.3 EQ 1.5 SS 1.3 EQ
Upstream Slope Steady State Conditions (1999): Pond surface @ El. 360 Potomac River @El. 376 -- 1.6 1.6 1.6

Upstream Slope Rapid Drawdown Conditions (1999): Pond drawdown to El. 360 (Approx. discharge pipe elev.) Pond drawdown to El. 347 1.2 1.4

1.1 1.4

1.1 1.4

1.1 Analyze liquefaction potential and safeguard against if needed No conclusion provided to CHA.

1. SS = Steady State loading conditions 2. EQ = Earthquake loading conditions

The upstream slope stability analyses performe d in 1999 indicate that the upstream slopes would be regraded with shale fill to return the slope s to a 3H:1V slope angle following over excavation during dredging operations. CHA did not observe shale fill along slopes still apparently at approximate 3H:1V slopes although deposited as h from successive years of pond use may have buried this fill. However, the northeast corner of the impoundment was severely over excavated during 2008 dredging operations resulting in an upst ream slope between 1.6H:1V to steeper than 1:1 based on a May 2009 survey and field obs ervations by CHA. Based on the May 2009 survey, slopes not over excavated during the la st dredging operation were between 2.5H:1V and
3H:1V.-52- Final Report Assessment of Dam Safety of Coal Combustion Surface Impoundments Allegheny Energy R. Paul Smith Station Williamsport, Maryland & Falling Waters, West Virginia An evaluation of liquefaction was not provided to CHA. However, subsurface information provided does not appear to s uggest liquefaction susceptible f oundation soils are found at this
site.

3.3.2 Ash Pond #4 – Structural Adequacy & Stability

GAI reviewed the structural stab ility of Ash Pond #4 as part of Allegheny Energy’s response to WVDEP’s Order of Compliance following the TVA Ki ngston incident. To evaluate the stability of the Ash Pond #4 dikes, GAI began by reviewing past reports by SRW in 1980 and SE Technologies in 1997. From soil borings performed by SRW in 1980, the st rata and associated engineering properties were identified at the site as shown in Table 4.

Table 4 – Ash Pond #4 Soil Parameters Used in Stability Analyses
Soil Stratum Unit Weight (pcf) Friction Angle (degrees) Cohesion (psf)
Shale Fill 135 38 0
Clay (Embankment Fill) 135 35 0 Soft to Medium Stiff Clay, some silt and sand 130 32 0 Medium Stiff to Stiff Clay, some silt and sand 135 35 0 Medium Stiff to Very Stiff Clay and Silt, some sand 135 31 0 Stiff to Very Stiff Clay and Silt, some sand 135 35 0

Sand and Gravel 140 38 0
Fly Ash 75 30 0 Note: not all strata were represented in each cross section analyzed.
GAI reproduced cross sections of the Ash Pond #4 dikes based on strata boundaries and soil propertied from the SRW cross section with th e exception of including a friction angle of 30 degrees for the fly ash, whereas SRW did not assume strength within the fly ash and a peak-53- Final Report Assessment of Dam Safety of Coal Combustion Surface Impoundments Allegheny Energy R. Paul Smith Station Williamsport, Maryland & Falling Waters, West Virginia ground acceleration of 0.08g was used as compared to SRW 0.05g. Cross sections of the north, east, and south dikes were evaluated for stability. The results of these analyses are presented in Table 5 below and graphical re presentation is presented in Figures 8A through 8H. The proposed bench listed in the ta ble is a proposed modification by GAI to meet upstream slope required factors of safety. The bench is proposed to be “left in place” fly ash. This bench will be created each time the pond is dr edged through a modification to the cleanout procedures and field survey indicating the lim its of dredging to occur.
Table 5 – Ash Pond #4 Engineering Comparison to Design Criteria

Design Consideration Criteria Nort h Dike East Dike South Dike

Steady State Normal Pool 1.5 1.5 1.5 1.5

Earthquake and

Normal Pool 1.2 1.3 1.2 1.2

Upstream Steady State Normal Pool with Proposed Bench 1.5 2.2 (deep) 1.4 (shallow) 2.6 (deep) 1.5 (shallow) Not Performed
Upstream Earthquake

Normal Pool with Proposed Bench 1.2 1.6 (deep) 1.2 (shallow) 1.8 (deep) 1.2 (shallow) Not Performed
Upstream Slope Rapid Drawdown with Proposed Bench 1.2 2.4 2.4 Not Performed

3.3.3 Instrumentation Review Relative to Stability

There are inactive pi ezometers on the Ash Pond #4 dikes that were installed in 1997. GAI found several of these piezometers and found water levels to be 30 or more fe et below the dam crest,
which is consistent with th e hypalon liner effectively preventing seepage through the
embankment.

There are no monitoring instru ments on the Ash Pond #3 dikes.-54- Final Report Assessment of Dam Safety of Coal Combustion Surface Impoundments Allegheny Energy R. Paul Smith Station Williamsport, Maryland & Falling Waters, West Virginia 3.4 Operations, Maintenance, and Inspections

West Virginia Rule 47CSR34 15.4 requires periodic safety inspections of dams as follows for Class 2, significant hazard dams:

• Monthly or more frequently by the Owner;

• At least every three years by the Owner’s engineer; and

• At any time as desired by the State.

According to our conversations w ith WVDEP, these inspections are only required to be visual inspections. Inspection reports for those inspections performed by the Owner’s engineer are to be submitted to WVDEP and are to include descript ions of maintenance work to be performed as a result of the inspection fi ndings. These reports ar e to be certified by an engineer to verify that the dam and its appurtenances are functioning as designed. Special insp ections are required following a storm event equal to or greater than a 50-year, 6 hour rainfall following the same reporting criteria, which at Ash Ponds #3 and #4 is about 4.5 inches according to National Weather Service’s Technical Paper No. 40 - Rainfall Frequency Atlas of the Eastern United States for Duration from 30 minutes to 24 hours and Return Periods from 1 to 100 years (TP40).

3.4.1 Inspection Procedures

Allegheny Energy hires an outside consultant to inspect the dams every two years. CHA was provided with copies of inspection reports for 2004, 2006, 2008 and 2009. Although earlier than usual, an additional inspection was performed in 2009 as a proactive measure following the TVA Kingston incident. These inspections are typica lly performed following vegetation clearing in the spring. These inspection repor ts are submitted to WVDEP.-55- Final Report Assessment of Dam Safety of Coal Combustion Surface Impoundments Allegheny Energy R. Paul Smith Station Williamsport, Maryland & Falling Waters, West Virginia Typical items of note during these inspections included small saplings taking root on the embankments, animal burrows, over excavation of upstream slopes during dredging, small holes in the hypalon liner at Ash Pond #4, sparse vege tation in some areas, minor surface sloughing
from runoff.

3.4.2 Inspections by West Virginia Dam Safety

WVDEP dam safety personnel make periodic inspec tions of Ash Ponds #3 and #4. Over the last five years, West Virginia Dam Safety personn el have made inspections in 2009, and 2006. The most recent inspection in 2009 wa s performed in follow-up to the TVA incident, and was part of a West Virginia Dam Safety initiative to have current site visits to each of the coal waste impoundments at power plants in the State.

Typical items of note during these inspections included removing animals and filling burrows, repair holes in the upstream liner at Ash Pond #4, monitor movement of the downstream slope where fence post foundations are exposed from surficial sloughing, and over excavation during dredging of the upstream slopes.

Brian Long, PE (WVDEP) indicated to CHA that the recommendations are of maintenance needs only. They do not use the inspection report as a medium for transmitting more serious concerns or needs at the dam. More serious issues, not addressed in a timely manner by the Owner on
their own accord would be addres sed via the Civil Administrative Penalties section of 47CSR34.

3.4.3 Maintenance

Allegheny Energy provided CHA w ith a copy of their Dam Safety Maintenance Plans for Ash Ponds #3 and #4 which were approved by WVDEP in May 2006. These maintenance plans-56- Final Report Assessment of Dam Safety of Coal Combustion Surface Impoundments Allegheny Energy R. Paul Smith Station Williamsport, Maryland & Falling Waters, West Virginia provide a matrix of maintenance activities and th e month in which these maintenance tasks are to be performed. The maintenance matrices ar e attached at the e nd of this section.

3.5 Foundation Conditions

Data reviewed by CHA indicates that Ash Ponds #3 and #4 were c onstructed on natural clay, silt and sand alluvial deposits. Constructed in the 1960s, no foundation preparation plans were
available for CHA’s review.- 67- Final Report Assessment of Dam Safety of Coal Combustion Surface Impoundments Allegheny Energy R. Paul Smith Station Williamsport, Maryland & Falling Waters, West Virginia 4.0 CONCLUSIONS/RECOMMENDATIONS

4.1 Acknowledgement of Management Unit Condition

I acknowledge that the management unit referenc ed herein was personally inspected by me and was found to be in the following condition: Satisfactory.

A management unit found to be in satisfactory c ondition is defined as one in which no existing or potential management unit safety deficien cies are recognized. A cceptable performance is expected under all applicable lo ading conditions in accordance w ith the applicab le criteria. Minor maintenance items may be required.

CHA presents the following recommendations fo r maintenance and updating of analyses in Sections 4.2 through 4.6.

4.2 Upstream Slopes

In reviewing historic documents for Ash Ponds #3 and #4, there were several mentions of portions of the upstream slopes of the dikes being over excavated during pond dredging operations. CHA observed this type of situa tion on the north end of the Ash Pond #3 dike. Proposed improvements to the Ash Pond #4 upstr eam slopes include leaving a buttress of deposited fly ash in place after each dredging. Careful survey control and monitoring of
contractor activities is needed to ensure that dredging operations do not alter th e slope angles needed to meet the required factors of safety with regard to slope stability.

In addition, before Ash Pond #3 is put back into service, the upstream slope in the northeast corner of the pond should be repa ired with compacted soil having similar characteristics to the design properties of the dam and pl aced to the designed slope angle.-68- Final Report Assessment of Dam Safety of Coal Combustion Surface Impoundments Allegheny Energy R. Paul Smith Station Williamsport, Maryland & Falling Waters, West Virginia 4.3 Downstream Slopes on Ash Pond #4

Surface soils were quite soft on the downstrea m slope of Ash Pond #4 and were subject to sloughing underfoot while walking on the slopes. Irre gularity in the slope surface and review of previous reports suggested that surface sloughing is an ongoing situation on the Ash Pond #4 dikes. In addition to general softness and grad ing irregularities, CHA observed erosion rills, and possible bulge areas as discussed in Section 2.3.1. CHA recommends quantitative monitoring of the downstream slope surfaces to provide better information regarding the nature of slope movements and changes.

Continued removal of brush and small shrubs is required. Trees between Ash Pond #4 and the Potomac River for the most part start just beyond the toe of the east dike. However, in a few locations, there are large trees wi thin the toe of the dike. CHA recommends at least a 10-foot
buffer zone between the toe of the dike and tree growth.

Some of the trees from beyond the toe of the east dike have branches nearing contact with upper portions of the slope. CHA recommends these bran ches be cut to facilitate access on the slope, and to prevent branches from r ooting on the slope of the dike.

4.4 Tree Removal on Ash Pond #3 Buttress

The stone fill buttress on the east dike of Ash P ond #3 is heavily covered in trees. Trees on embankments can compromise the integrity of the slope by creating scarps if trees fall over from age or during a storm, and roots penetrating into the embankment can provide preferential paths for seepage. In addition, these trees make in spection of the toe of the buttress difficult. Therefore, CHA recommends the tree s along the buttress be removed.-69- Final Report Assessment of Dam Safety of Coal Combustion Surface Impoundments Allegheny Energy R. Paul Smith Station Williamsport, Maryland & Falling Waters, West Virginia 4.5 Monitoring Instrumentation

CHA recommends piezometers be installed on th e Ash Pond #3 dikes to evaluate the phreatic surface with relation to the phreatic surfaced a ssumed for the stability analyses. Routine monitoring of the phreatic surface should be established with corresponding elevations of the water and ash levels within the pond at th e time of measurement for a comprehensive understanding of the embankment behavior.

4.6 Evaluation of Conditions from Potomac River Flooding

CHA understands that the Ash Pond #3 dikes were raised in 1980 to be 3.4 feet higher than the
water surface elevation attained by the Potomac River at Williamsport during Hurricane Agnes
in 1972. A brief review of hi storical flood records suggests that Hurricane Agnes has crested in the vicinity of Williamsport higher than the flows from Hurricane Agnes at least five times since 1936. CHA recommends that a comprehensive, proba bilistic analysis of fl ood elevations in the Potomac River at Williamsport be performed. This analysis should include estimated river
velocities at the stream banks to evaluate the adequacy of the rip rap protection on Ash Pond #3 and whether bank armoring is needed on Ash Pond #4.-70- Final Report Assessment of Dam Safety of Coal Combustion Surface Impoundments Allegheny Energy R. Paul Smith Station Williamsport, Maryland & Falling Waters, West Virginia 5.0 CLOSING

The information presented in this report is base d on visual field observati ons, review of reports by others and this limited knowledge of the hist ory of the R. Paul Smith Station surface impoundments. The recommendations presented are based, in part, on project information
available at the time of this report. No other warranty, expre ssed or implied is made. Should additional information or changes in fiel d conditions occur, the conclusions and recommendations provided in this report should be re-evaluated by an experienced engineer.Final Report Assessment of Dam Safety of Coal Combustion Surface Impoundments Allegheny Energy R. Paul Smith Station Williamsport, Maryland & Falling Waters, West Virginia 

## APPENDIX A

Completed EPA Coal Combustion Dam Inspection Checklist Forms
& Completed EPA Coal Co mbustion Waste (CCW) Impoundment Inspection FormsSite Name: Date: Unit Name: Operator's Name: Unit I.D.: Hazard Potential Classification : High Significant Low Inspector's Name: Coal Combustion Dam Inspection Checklist Form US Environmental Protection Agency

Check the appropriate box below. Provide comments when appropriate. If not applicable or not available, record "N/A". Any unusua l conditions or construction practices that should be noted in the comments section. For large diked embankments, separate checklists may be use d for different embankment areas. If separate forms are used, identify approximate area that the form applies to in comments. Yes No Yes No

1. Frequency of Company's Dam Inspections? 18. Sloughing or bulging on slopes? 2. Pool elevation (operator records)? 19. Major erosion or slope deterioration? 3. Decant inlet elevation (operator records)? 20. Decant Pipes: 4. Open channel spillway elevation (operator records)? Is water entering inlet, but not exiting outlet? 5. Lowest dam crest elevation (operator records)? Is water exiting outlet, but not entering inlet? 6. If instrumentation is present, are readings recorded (operator records)? Is water exiting outlet flowing clear?

7. Is the embankment currently under construction? 21. Seepage (specify location, if seepage carries fines, and approximate seepage rate below): 8. Foundation preparation (remove vegetation,stumps, topsoil in area where embankment fill will be placed)? From underdrain? 9. Trees growing on embankment? (If so, indicate largest diameter below) At isolated points on embankment slopes?
10. Cracks or scarps on crest? At natural hillside in the embankment area? 11. Is there significant settlement along the crest? Over widespread areas? 12. Are decant trashracks clear and in place? From downstream foundation area? 13. Depressions or sinkholes in tailings surface or whirlpool in the pool area? "Boils" beneath stream or ponded water?
14. Clogged spillways, groin or diversion ditches? Around the outside of the decant pipe? 15. Are spillway or ditch linings deteriorated? 22. Surface movements in valley bottom or on hillside?

16. Are outlets of decant or underdrains blocked? 23. Water against downstream toe?
17. Cracks or scarps on slopes? 24. Were Photos taken during the dam inspection? Major adverse changes in these items could cause instability and should be reported for further evaluation. Adverse conditions noted in these items should normally be described (extent, location, volume, etc.) in the space below and on the back of this sheet.

Inspection Issue # Comments

EPA FORM -XXXX R . Paul Smith Power Station 1 0-20-09 A sh Pond #3 Allegheny Energy A sh Pond #3

A nnually K atherine Adnams & Khalid Abed, P.E.

S ee Note

3 68

N A S ee Note 2 3 79.4 N A X X

X X N A

N A N A

See Note X

X

X
X X

X

X X

X X

X
X X

X X X X
X

N/A = Not Applicable/Available

P ond #3 is currently in the dredged state and is not in operation. Remaining water is below the lowest decant elevation. Pond #3

w ill return to service when Pond #4 is full. Highest decant elevation at 368.0

T rees were noted on the stone buttress not the original dike slope.

R outine maintenance item for Allegheny Energy includes clearing debris deposited at discharge channel/Potomac River confluenc e.

D ebris gets deposited during recession of high flows on the Potomac River. 2

.

14.

2 1

. A seepage area is monitored to the south of Ash Basin #3. No flow was observed in standing water. Allegheny Energy believes the 9

.

wet area is related to stormwater drainage from hillside through adjacent wetland, but continue to monitor. No fines observed.

23. T he toe of the stone buttress is approximately at the waters edge of the Potomac River. Flooding on the Potomac will rise against the dik e.U. S. Environmental Protection Agency

Coal Combustion Waste (CCW) Impoundment Inspection

Impoundment NPDES Permit # _____________________ INSPECTOR______________________ 

### Date ____________________________________
Impoundment Name ________________________________________________________ Impoundment Company ____________________________________________________ EPA Region ___________________ State Agency (Field Office) Addresss __________________________________________

__________________________________________ Name of Impoundment _____________________________________________________ (Report each impoundment on a separate form under the same Impoundment NPDES Permit number)
New ________ Update _________

Yes No Is impoundment currently under construction? ______ ______ Is water or ccw currently being pumped into the impoundment? ______ ______

IMPOUNDMENT FUNCTION :

_____________________________________________

Nearest Downstream Town : Name ____________________________________ Distance from the impoundment __________________________ Impoundment Location: Longitude ______ Degrees ______ Minutes ______ Seconds Latitude ______ Degrees ______ Minutes ______ Seconds State _________ County ___________________________
Does a state agency regulate this impoundment? YES ______ NO ______
If So Which State Agency?___________________________________________

EPA Form XXXX-XXX, Jan 09 1 M D0000582 Adnams/Abed
O ctober 20, 2009

Ash Pond #3 Allegheny Energy 3 1800 Washington Boulevard Baltimore, MD 21230 A sh Pond #3

X

X

X

Receives all CCW related waste water from the plant. Alternates use with Ash Pond #4

F alling Water, WV Approx. 4.5 miles

7 7 49 5 1 3 9 35 5 1 W V Berkeley

X

M D Department of the Environment - NPDES W V Department of Environmental Protection - Dam Safety

### HAZARD POTENTIAL (In the event the impoundment should fail, the following would occur):

______ LESS THAN LOW HAZARD POTENTIAL: Failure or misoperation of the dam results in no probable loss of human life or economic or environmental losses.

______ LOW HAZARD POTENTIAL: Dams assigned the low hazard potential classification are those where failure or misoperation results in no probable loss of human life and low economic and/or environmental losses. Losses are principally limited to the owner’s property.

______ SIGNIFICANT HAZARD POTENTIAL: Dams assigned the significant hazard potential classification are those dams where failure or misoperation results in no probable loss of human life but can cause economic loss, environmental damage, disruption of lifeline facilities, or can impact other concerns. Significant hazard potential classification dams are often located in predominantly rural or agricultural areas but could be located in areas with population and significant infrastructure.

______ HIGH HAZARD POTENTIAL: Dams assigned the high hazard potential classification are those where failure or misoperation will probably cause loss of human life.

DESCRIBE REASONING FOR HAZARD RATING CHOSEN:

_________________________________________________________________

_________________________________________________________________

_________________________________________________________________

_________________________________________________________________

_________________________________________________________________

_________________________________________________________________

_________________________________________________________________

_________________________________________________________________

_________________________________________________________________

_________________________________________________________________

_________________________________________________________________

_________________________________________________________________

_________________________________________________________________

_________________________________________________________________

_________________________________________________________________

EPA Form XXXX-XXX, Jan 09 2 X

R elatively small impoundments compared to volume of the Potomac River and elevation of

r iverfront homes suggest loss of life is not a concern. However, environmental impacts to th e P otomac River if a breach were to occur would cause environmental damage.

### CONFIGURATION :

Height original ground

CROSS-VALLEY

Height original ground

SIDE-HILL

Water or ccw DIKED

original ground Height Height original ground

CROSS-VALLEY Water or ccw

original ground

SIDE-HILL Height original ground

CROSS-VALLEY

original ground

SIDE-HILL Height original ground

SIDE-HILL Water or ccw

INCISED

Water or ccw

original ground 

### _____ Cross-Valley _____ Side-Hill _____ Diked _____ Incised (form completion optional) 

### _____ Combination Incised/Diked Embankment Height __________ feet Embankment Material_______________ Pool Area __________________ acres Liner ____________________________ Current Freeboard ___________ feet Liner Permeability _________________

EPA Form XXXX-XXX, Jan 09 3 X

46 H omogeneous compacted fi ll ~6 at maximum decant None
14 at max. decant NA

### TYPE OF OUTLET (Mark all that apply)

TRAPEZOIDAL

Avg Depth Bottom Width Depth TRIANGULAR



### _____ Open Channel Spillway _____ Trapezoidal Top Width Top Width 

### _____ Triangular

RECTANGULAR IRREGULAR Depth 

### _____ Rectangular _____ Irregular
_____ depth _____ bottom (or average) width

Width Depth Average Width 

### _____ top width

_____ Outlet
_____ inside diameter

Material Inside Diameter 

### _____ corrugated metal _____ welded steel _____ concrete _____ plastic (hdpe, pvc, etc.) _____ other (specify) ____________________

Is water flowing through the outlet? YES _______ NO _______

_____ No Outlet

_____ Other Type of Outlet (specify) ________________________________

The Impoundment was Designed By ____________________________________

__________________________________________________________________

EPA Form XXXX-XXX, Jan 09 4 X

14-in.

X HDPE Sliplined CMP

X

Unknown

### Has there ever been a failure at this site? YES __________ NO ___________
If So When? ___________________________
If So Please Describe : _____________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

EPA Form XXXX-XXX, Jan 09 5 X

December 1998

I n December 1998 a breach of the outlet pipe occurred. According to Allegheny Energy no release of impounded material occurred. This failure occured after a decant structure/outlet slip lining project had been
p erformed at Pond #4 in 1997 under maintenance operations.

### Has there ever been significant seepages at this site? YES _______ NO _______
If So When? ___________________________
IF So Please Describe: _______________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

EPA Form XXXX-XXX, Jan 09 6 X

### Has there ever been any measures undertaken to monitor/lower Phreatic water table levels based on past seepages or breaches at this site? YES ________NO ________
If so, which method (e.g., piezometers, gw pumping,...)? ____________________
If so Please Describe : ____________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

EPA Form XXXX-XXX, Jan 09 7 XSite Name: Date: Unit Name: Operator's Name: Unit I.D.: Hazard Potential Classification : High Significant Low Inspector's Name: Coal Combustion Dam Inspection Checklist Form US Environmental Protection Agency

Check the appropriate box below. Provide comments when appropriate. If not applicable or not available, record "N/A". Any unusua l conditions or construction practices that should be noted in the comments section. For large diked embankments, separate checklists may be use d for different embankment areas. If separate forms are used, identify approximate area that the form applies to in comments. Yes No Yes No

1. Frequency of Company's Dam Inspections? 18. Sloughing or bulging on slopes? 2. Pool elevation (operator records)? 19. Major erosion or slope deterioration? 3. Decant inlet elevation (operator records)? 20. Decant Pipes: 4. Open channel spillway elevation (operator records)? Is water entering inlet, but not exiting outlet? 5. Lowest dam crest elevation (operator records)? Is water exiting outlet, but not entering inlet? 6. If instrumentation is present, are readings recorded (operator records)? Is water exiting outlet flowing clear?

7. Is the embankment currently under construction? 21. Seepage (specify location, if seepage carries fines, and approximate seepage rate below): 8. Foundation preparation (remove vegetation,stumps, topsoil in area where embankment fill will be placed)? From underdrain? 9. Trees growing on embankment? (If so, indicate largest diameter below) At isolated points on embankment slopes?
10. Cracks or scarps on crest? At natural hillside in the embankment area? 11. Is there significant settlement along the crest? Over widespread areas? 12. Are decant trashracks clear and in place? From downstream foundation area? 13. Depressions or sinkholes in tailings surface or whirlpool in the pool area? "Boils" beneath stream or ponded water?
14. Clogged spillways, groin or diversion ditches? Around the outside of the decant pipe? 15. Are spillway or ditch linings deteriorated? 22. Surface movements in valley bottom or on hillside?

16. Are outlets of decant or underdrains blocked? 23. Water against downstream toe?
17. Cracks or scarps on slopes? 24. Were Photos taken during the dam inspection? Major adverse changes in these items could cause instability and should be reported for further evaluation. Adverse conditions noted in these items should normally be described (extent, location, volume, etc.) in the space below and on the back of this sheet.

Inspection Issue # Comments

EPA FORM -XXXX R . Paul Smith Power Station 1 0-20-09 A sh Pond #4 Allegheny Energy A sh Pond #4

B iennially K atherine Adnams & Khalid Abed, P.E.

X 3 67.7

3 67.7

N A 3 78 X X

X X X

N A N A

X

X

X X

X
X X X

X X

X
X X

X X

X X X
X

N/A = Not Applicable/Available.

O ccasional small shrubs were noted on the south dike.

S urface soils on dike slopes are soft and prone to erosion. No serious areas of concern were noted.

. Small surface sloughs occur when walking on particularly soft surface soils. A few areas of possible bulges were noted, but were

r eported by Allegheny Energy to be observed during routine inspections and changes had not been observed in many years. 9.

1 8. 19.U. S. Environmental Protection Agency

Coal Combustion Waste (CCW) Impoundment Inspection

Impoundment NPDES Permit # _____________________ INSPECTOR______________________ 

### Date ____________________________________
Impoundment Name ________________________________________________________ Impoundment Company ____________________________________________________ EPA Region ___________________ State Agency (Field Office) Addresss __________________________________________

__________________________________________ Name of Impoundment _____________________________________________________ (Report each impoundment on a separate form under the same Impoundment NPDES Permit number)
New ________ Update _________

Yes No Is impoundment currently under construction? ______ ______ Is water or ccw currently being pumped into the impoundment? ______ ______

IMPOUNDMENT FUNCTION :

_____________________________________________

Nearest Downstream Town : Name ____________________________________ Distance from the impoundment __________________________ Impoundment Location: Longitude ______ Degrees ______ Minutes ______ Seconds Latitude ______ Degrees ______ Minutes ______ Seconds State _________ County ___________________________
Does a state agency regulate this impoundment? YES ______ NO ______
If So Which State Agency?___________________________________________

EPA Form XXXX-XXX, Jan 09 1 M D0000582 Adnams/Abed
O ctober 20, 2009

Ash Pond #4 Allegheny Energy 3 1800 Washington Boulevard Baltimore, MD 21230 A sh Pond #4

X

X

X

Receives all CCW related waste water from the plant. Alternates use with Ash Pond #3

F alling Water, WV Approx. 4.5 miles

7 7 49 5 1 3 9 35 5 1 W V Berkeley

X

M D Department of the Environment - NPDES W V Department of Environmental Protection - Dam Safety

### HAZARD POTENTIAL (In the event the impoundment should fail, the following would occur):

______ LESS THAN LOW HAZARD POTENTIAL: Failure or misoperation of the dam results in no probable loss of human life or economic or environmental losses.

______ LOW HAZARD POTENTIAL: Dams assigned the low hazard potential classification are those where failure or misoperation results in no probable loss of human life and low economic and/or environmental losses. Losses are principally limited to the owner’s property.

______ SIGNIFICANT HAZARD POTENTIAL: Dams assigned the significant hazard potential classification are those dams where failure or misoperation results in no probable loss of human life but can cause economic loss, environmental damage, disruption of lifeline facilities, or can impact other concerns. Significant hazard potential classification dams are often located in predominantly rural or agricultural areas but could be located in areas with population and significant infrastructure.

______ HIGH HAZARD POTENTIAL: Dams assigned the high hazard potential classification are those where failure or misoperation will probably cause loss of human life.

DESCRIBE REASONING FOR HAZARD RATING CHOSEN:

_________________________________________________________________

_________________________________________________________________

_________________________________________________________________

_________________________________________________________________

_________________________________________________________________

_________________________________________________________________

_________________________________________________________________

_________________________________________________________________

_________________________________________________________________

_________________________________________________________________

_________________________________________________________________

_________________________________________________________________

_________________________________________________________________

_________________________________________________________________

_________________________________________________________________

EPA Form XXXX-XXX, Jan 09 2 X

R elatively small impoundment compared to volume of the Potomac River and elevation of

r iverfront homes suggest loss of life is not a concern. However, environmental impacts to th e P otomac River if a breach were to occur would cause environmental damage.

### CONFIGURATION :

Height original ground

CROSS-VALLEY

Height original ground

SIDE-HILL

Water or ccw DIKED

original ground Height Height original ground

CROSS-VALLEY Water or ccw

original ground

SIDE-HILL Height original ground

CROSS-VALLEY

original ground

SIDE-HILL Height original ground

SIDE-HILL Water or ccw

INCISED

Water or ccw

original ground 

### _____ Cross-Valley _____ Side-Hill _____ Diked _____ Incised (form completion optional) 

### _____ Combination Incised/Diked Embankment Height __________ feet Embankment Material_______________ Pool Area __________________ acres Liner ____________________________ Current Freeboard ___________ feet Liner Permeability _________________

EPA Form XXXX-XXX, Jan 09 3 X

41 H omogeneous compacted fi ll ~11 at maximum decant Hypalon
10 at max. decant impermeable

### TYPE OF OUTLET (Mark all that apply)

TRAPEZOIDAL

Avg Depth Bottom Width Depth TRIANGULAR



### _____ Open Channel Spillway _____ Trapezoidal Top Width Top Width 

### _____ Triangular

RECTANGULAR IRREGULAR Depth 

### _____ Rectangular _____ Irregular
_____ depth _____ bottom (or average) width

Width Depth Average Width 

### _____ top width

_____ Outlet
_____ inside diameter

Material Inside Diameter 

### _____ corrugated metal _____ welded steel _____ concrete _____ plastic (hdpe, pvc, etc.) _____ other (specify) ____________________

Is water flowing through the outlet? YES _______ NO _______

_____ No Outlet

_____ Other Type of Outlet (specify) ________________________________

The Impoundment was Designed By ____________________________________

__________________________________________________________________

EPA Form XXXX-XXX, Jan 09 4 X

14-in.

X HDPE Sliplined CMP

X

Unknown

### Has there ever been a failure at this site? YES __________ NO ___________
If So When? ___________________________
If So Please Describe : _____________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

EPA Form XXXX-XXX, Jan 09 5 X

### Has there ever been significant seepages at this site? YES _______ NO _______
If So When? ___________________________
IF So Please Describe: _______________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

EPA Form XXXX-XXX, Jan 09 6 A Hypalon liner has been installed. Current employees of Allegheny Energy were
u ncertain the exact reasons the liner was installed, but suspect it was to reduce
s eepage and/or lower the phreatic water surface through the embankment. (Unknown)

### Has there ever been any measures undertaken to monitor/lower Phreatic water table levels based on past seepages or breaches at this site? YES ________NO ________
If so, which method (e.g., piezometers, gw pumping,...)? ____________________
If so Please Describe : ____________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

EPA Form XXXX-XXX, Jan 09 7 X

A Hypalon liner has been installed. Current employees of Allegheny Energy were uncertain th e
e xact reasons the liner was installed, but suspect it was to reduce seepage and/or lower the p hreatic water surface through the embankment.