Response to EPA Information Request

Urquhart Station

1

EPA Information Request for Urquhart Station

1. Identify the name, address, telephone number, and location of the current legal owner(s) and

operator(s) of South Carolina Electric and Gas, Urquhart Station, as well as, the name, address,

telephone number, and location of its parent company.

Urquhart Station is owned and operated by the South Carolina Electric and Gas Company, a wholly

owned subsidiary of:  

SCANA Corporation

100 SCANA Parkway

Cayce, SC 29033‐3712

803‐217‐9000

2. On a topographic map, using the most recent USGS 7 1⁄2 minute or 15 minute topographic

quadrangle map, show the location of the facility boundaries, as well as all surface water flows,

including tributaries, streams, rivers, lakes, ponds, and wetlands, within the facility boundaries

that cross into or are adjacent to the facility boundaries.

See attached maps Urquhart – upper.pdf, Urquhart – lower.pdf, and URQUHART Facility Map (8‐12‐

10).pdf.   

3. List and label each area located at the facility that the company uses or has used to collect,

store, treat, or dispose of fly ash, bottom ash, slag, combined fly ash and bottom ash, flue gas

desulfurization sludge, co‐disposed and co‐managed ash and coal refuse, solid waste, hazardous

waste, as well as wastewater, including process wastewater, waste slurry or sludge, cooling

water, storm water runoff, and sanitary wastewater, on an episodic or routine basis

(“management areas”).  For each of these areas include, but are not limited to, underground

mines, underground injection wells, landfills, tanks, ponds, lagoons, basins, storm drains, pipes,

and surface impoundments.

See attached maps Urquhart – upper.pdf, Urquhart – lower.pdf, and URQUHART Facility Map (8‐12‐

10).pdf.   

Ash Pond No. 1 (Primary) & 2 (Secondary):  The primary and secondary ash ponds operate in series and

treat wastewater from the ash handling area sumps.       

Low‐Volume Waste  Ponds No. 1 (Primary) & 2 (Secondary) :  The Low Volume Waste Ponds operate in

series and primarily treat coal pile runoff, cooling tower/boiler blowdown, and the remainder of the

plant process wastewaters.   

There are two additional ponds on site, the no discharge Metals Cleaning Pond and the Ash Landfill

Runoff Pond (Outfall 003).  The Metals Cleaning Pond was last used in December 2001. The last boiler

cleaning was completed in May 2006 using tetra ammonium EDTA which is evaporated in the boiler in

accordance with the air permit requirements.  The drainage from the landfill runoff is by grassed
Response to EPA Information Request

Urquhart Station

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conveyances to the Ash Landfill Runoff Pond that discharges to NPDES Outfall 003. Both of these ponds

are typically dry.  

Landfill ‐ The facility has a SCDHEC permitted landfill onsite that is permitted to receive fly ash and

bottom ash resulting from the electric power generation process.   

Low‐Volume/Landfill Area Stormwater Pond and the Re‐Power Area Stormwater Detention Pond:  The

Re‐Power Area Stormwater Detention Pond can receive runoff from the adjacent switchyard.  This pond

discharges through stormwater Outfall SW‐3.  The Low‐Volume/Landfill Area Stormwater Pond is

adjacent to the road to the low‐volume waste ponds and landfill.  Its purpose is to capture and settle

solids from the road.  This pond typically does not discharge, but could through stormwater Outfall SW‐

4.  Both of these ponds are typically dry.  

Flyash Silos: The flyash storage silos are located near the entrance to the facility. They use overhead

hoppers that transfer ash into trucks for disposal in the on‐site landfill or for sale.  Quantities generated

will vary with on‐going activities.   

Bottom Ash Dewatering Bins:  The bottom ash dewatering bins are located near the entrance to the

facility.  They use overhead hoppers that transfer ash into trucks for disposal in the on‐site landfill or for

sale.  Quantities generated will vary with on‐going activities.   

Hazardous Waste Storage:  Hazardous waste generation at the Urquhart Station is minimal. The facility

maintains a Conditionally Exempt Small Quantity (CESQ) generator status.  Storage amounts vary but

typically 1‐2 drums are stored temporarily in the accumulation area, if applicable.  The area is covered

and fenced to minimize personnel entrance. The waste remains on‐site until removed by licensed

transporters for disposal at the TSDF.

Groundwater Monitoring Wells:  Various ground water monitoring wells are located adjacent to the

pond and landfill as depicted on the attached topographical map. These wells are part of the NPDES and

ISWF requirements.

4. For each management area, identify its location and boundaries on the map provided in

response to question #2.

See attached maps Urquhart – upper.pdf , Urquhart – lower.pdf, and URQUHART Facility Map (8‐12‐

10).pdf.pdf.   

5. For each management area, describe the area’s approximate storage capacity, the volume of

waste or wastewater currently stored, and the approximate proportion of free liquid and settled

solids within the stored wastewater.  Explain how the company calculated these volumes.

Please see attached spreadsheet (Mgmt Area Volumes ‐ Urquhart.xls) for the requested information.  

Further information is included in the attached document (Urquhart Pond Volumes (8‐12‐10).pdf).

6. Provide the name of any entity with whom you have contracted for the disposal, sale, or

reuse/recycling of coal combustion waste generated from your facility for the past five (5) years.  
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Urquhart Station

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Identify the type and amount of coal combustion waste that the company disposed of through

such contracts each year for the past five (5) years.

Coal

Combustion

Product

Use 2009

(tons)  

2008

(tons)

2007

(tons)

2006

(tons)

2005

(tons)

SEFA Group Carbon burnout

& STAR

beneficiated fly

ash

Concrete Mfg. 9,973   5,152 3,831 2,719 6,298

Bricko

Farms Inc.

bottom ash   Bottom ash mixed with

cement & sand used as

structural fill in walkways

& parking lot

improvements

0 0 0 727 1,400

7. Identify all the waste streams generated at the facility for the past five (5) years.  Referring to

the labels provided for each management area provide a flow diagram showing each waste

stream from the source of generation to its final disposition.  In the flow diagram, include the

following information: (a) description of the waste streams (including, but not limited to, fly ash,

bottom ash and slag, combined fly and bottom ash, flue gas desulfurization sludge, co‐disposed

and co‐managed ash and coal refuse) and their chemical characterizations; (b) the daily and

annual volume of each waste stream flow; and (c) the final disposition of the waste streams,

including materials recycled or otherwise destined for beneficial use.   

Waste streams generated during the past 5 years include: (a) process water, (b) fly ash, (c) bottom ash.  

See attached Urquhart water/wastewater flow diagram (20100621093908246.pdf) and DMRs in

question #8 for process water flow quantities. See attached flow diagram of fly and bottom ash

production to disposal site (Urquhart Ash Storage.doc). Wastewater discharges from this facility are

permitted under NPDES Permit No. SC0000574 and consist of:

• Outfall 001 – the discharge point for the plant’s once‐through cooling system.  Roof drains

and some storm water drains also are discharged at Outfall 001.   

• Outfall 002 – the discharge point for the combined effluent from the low volume waste

ponds and the ash ponds.  See below for further description of pond effluents.

• Outfall 003 – the discharge point for water collected in the ash landfill runoff retention

pond.   
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Urquhart Station

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River water is used to power an ejector to produce the vacuum needed to pneumatically transport

fly ash from the collection hoppers to a storage silo.  A mechanical separator on top of the silo

separates most of the fly ash from the conveying air and deposits it in the silo in a dry state.  Some

amount of the fly ash carries over and mixes with the motive water.  The motive water is discharged

to the primary ash pond, and then to the secondary ash pond for settlement of ash carried over with

the water.  Fly ash stored in the silo is either transported to the on‐site landfill or sold for beneficial

use.

Bottom ash is collected in a water‐filled hopper and sluiced by river water to a sump.  River water is

used by centrifugal pumps to transport bottom ash from the sump to dewatering bins.  Ash is

retained in the dewatering bins.  Transport water flows to the primary ash pond, and then to the

secondary ash pond for settlement of solids that might be carried over with the transport water.  

Bottom ash stored in the dewatering bin is either transported to the on‐site landfill or sold for

beneficial use.

The total wastewater flow from the ash ponds to Outfall 002 will vary with on‐going operations.  

Solids collected in the ash ponds are periodically removed from the ponds and transported to the

ash landfill.

The low volume waste pond collects coal pile runoff, other low‐volume and miscellaneous process

wastewaters (boiler blowdown, demineralizer regeneration wastes, water treatment equipment

backwash flows, lab wastes, cooling tower blowdown, gas turbine compressor wash water,

equipment wash water), and runoff from areas of industrial activity.  These wastewater streams

flow by gravity to the primary low volume waste pond, or they are collected in various sumps on the

site and are pumped to the primary low volume waste pond.  Certain waste streams that could

contain oily wastes flow through one of two oil/water separators before being discharged to the low

volume waste pond.  Wastewater flows from the Units 5 & 6 area are treated in a neutralization

sump prior to discharge to the low volume waste pond.  Wastewater entering the primary low

volume waste pond flows through the primary pond and then through the secondary low volume

waste pond for settlement of suspended solids before being discharged to Outfall 002.

The total wastewater flow from the low volume waste ponds to Outfall 002 is approximately 0.57

MGD.  Solids collected in the low volume waste ponds are periodically removed from the ponds and

transported to the ash landfill.  The overall long‐term average flow at Outfall 002 is 1.77 MGD, based

on DMR values.

The chart below summarizes the annual amount of fly and bottom ash produced and the final

disposition of the ash.

Year Fly Ash Produced  

(Dry tons)

Bottom Ash

Produced (tons)

Total Ash for

Beneficial Use

Fly Ash to

Landfill (tons)

Bottom Ash to

Pond (tons)

2009 12,722 3,181 9,973 2,749 3,181

2008 26,291 2,921 5,152 21,139 2,921

2007 24,919 2,769 3,831 21,088 2,769

2006 18,776 2,086 3,446 16,057 1,359
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2005 18,151 2,017 7,698 11,853 617

8. Provide any testing and analyses relied on to determine the characterization of the waste

streams, as well as any sampling results of the waste streams obtained by the facility for the

past five (5) years.  For any sampling results provided, include a description of the sampling

procedures used.

Concerning the characterization of waste streams, attached is an ash characterization study

(sceg03704c‐urquhart‐rpt.pdf) that was conducted per South Carolina Regulation 61‐107.19, Solid

Waste Management. All samples were analyzed per EPA Methods as outlined in the report. Also

attached are the latest 2C applications that analyze all waste streams from the plant and five years

of NPDES Permit Discharge Monitoring Reports. All samples were analyzed per EPA Methods as

required by the NPDES permit /CFR Part 136.  All surface waters samples are monitored per the

SCDHEC Practical Quantitation Limits (PQLs) and performed by a SCDHEC Certified lab per SCDHEC

R.61‐81.   

  Please see attached:

(a) Fly ash, bottom ash, pyrites, ash settling pond, coal pile runoff pond waste characterization

report  (sceg03704c‐urquhart‐rpt.pdf)

(b) 2C Applications for chemical analyses of Water/wastewater streams (20100621093543715.pdf,

20100621093653980.pdf,   20100621093816443.pdf)

(c) Discharge Monitoring Reports (Urquhart 01‐06 DMR.pdf thru Urquhart 12‐09 DMR.pdf)

9. Describe any wastewater discharges, including overflows, diversions, or other releases, that

occur or have occurred within the last ten (10) years from the management areas to surface

waters, including tributaries, streams, rivers, lakes, ponds, and wetlands.  Identify the discharge

points and runoff paths on the map provided in response to request #2.  Provide any analytical

data or monitoring results from the last five (5) years that demonstrate hazard constituents in

the wastewater discharges from the management areas to surface waters.  Identify the

management plans and treatment technologies that the company implements to control

wastewater discharges.  Provide a copy of the National Pollutant Discharge Elimination System

(NPDES) permit that authorizes these wastewater discharges.  If the company has not obtained

permit coverage, provide an explanation for this lack of coverage.  Submit any discharge

monitoring reports in which the company reported any wastewater violations from the last five

(5) years.

There have been no unpermitted NPDES wastewater discharges or by‐passes from the wastewater

system within the past 10 years.  Three wastewater outfalls discharge from this facility to the

Savannah River and are permitted under National Pollutant Discharge Elimination System (NPDES)

Permit No. SC0000574.  These outfalls consist of:
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Urquhart Station

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Outfall 001

A 112 MGD (long‐term average) discharge of once‐through cooling water, house service cooling water

Outfall 002

A 1.77 MGD (long‐term average) discharge of several wastewater sources treated through multiple

treatment units (oil/water separators, neutralization, settling ponds, etc.) including but not limited to:

• storm water runoff from the coal pile, containments, area drains, etc.

• water treatment system discharges

• cooling tower and boiler blowdown

• ash handling sumps

• other low volume wastes

Outfall 003

An outfall from the settling pond for the ash landfill runoff.

The Urquhart Station treatment system is primarily comprised of a collection/transmission system,

oil/water separation units, a neutralization basin, and two series of settling/treatment ponds (Ash Pile

Ponds 1 & 2 and Low Volume Waste Ponds 1 & 2) prior to discharge through the primary NPDES outfall,

Outfall 002.  Outfall 001 consists primarily of untreated once‐through cooling water, and Outfall 003 is

for the discharge of ash landfill runoff from a settling basin, though it has not discharged to date.

The series of ponds that make up the site wastewater treatment system are designed such that all

wastewater discharged to the Savannah River meets the applicable state water quality standards,

the applicable Federal Effluent Limitations Guidelines established by EPA for Steam and Electric

Generating facilities, and the associated discharge limitations of permit SC0002038.  Please see

attached Urquhart Station NPDES permit (Urquhart Aug. 1, 2005 – Sep. 30, 2008.pdf).  Please see

attached oil spill report for an oil spill that occurred in May 2009 that was subsequently reported to

the NRC and DHEC (URQ oil spill 5 09.doc) attributed to contactor activities.

10. For all stormwater discharges associated with industrial activity from the facility, as defined at

40 CFR Sect. 122.26(a)(14), identify the industrial activity (including the appropriate NAICS and

SIC codes) that require coverage under an NPDES permit.  In addition to the information

provided about these discharges in response #9, provide a copy of the facility’s current

Stormwater Pollution Prevention Plan (SWPPP) as well as copies of its comprehensive site

evaluations, inspection records, and monitoring results for the last five (5) years.  If the company

has not developed a SWPPP, provide an explanation for this decision.

The SIC and NAICS codes for Urquhart Station (Electric Power Generation) are 4911 and 221112,

respectively.  Most storm water associated with industrial activities that has a high potential of

contamination of runoff is treated in the facility’s NPDES treatment system to remove most

suspended solids, oil and grease, and high or low pH prior to discharge.  Runoff treated in this

system includes that from the coal pile and coal handling areas, ash handling area, fuel oil unloading

area, and all runoff in the immediate vicinity or the boiler and associated equipment areas.

Storm water that is not treated in the NPDES treatment system is generally from grassy or wooded

areas, plant roads, parking lots, and surrounding grassed.  Storm water from nine discharge outfalls
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(SW‐1, SW‐1A, SW‐1B, SW‐2, SW‐3, and SW‐4, SW‐5, SW‐6, and SW‐7) are covered under South

Carolina General NPDES Permit (SCR000000) for Storm Water Discharges Associated with Industrial

Activities.  This permit requires the development and maintenance of a Storm Water Pollution

Prevention Plan (SWPPP).  

Please see attached:

(a) Stormwater Pollution Prevention Plan (SWPPP) (Stormwater Pollution Prevention Plan Revision

6 May 2009 (SWPPP).pdf)

(b) Stormwater monitoring reports (Stormwater Monitoring Results 062606 Part A.pdf,  Stormwater

Monitoring Results 062606 Part B.pdf,  Stormwater Monitoring Results 061218 Part A.pdf,

Stormwater Monitoring Results 061218 Part B.pdf, Stormwater Monitoring Results 071215 .pdf,

Stormwater Monitoring Results 080726.pdf, Stormwater Monitoring Results 050420.pdf,

Stormwater Monitoring Results 050729.pdf, Stormwater Monitoring Results 051220 Part A.pdf,

Stormwater Monitoring Results 051220 Part B.pdf, Stormwater Monitoring Results 051228 Part

A.pdf, Stormwater Monitoring Results 051228 Part B.pdf)

(c) Quarterly Inspection reports (Stormwater Quarterly Inspection 2005.pdf,  Stormwater Quarterly

Inspection 2006.pdf,  Stormwater Quarterly Inspection 2007.pdf,  Stormwater Quarterly

Inspection 2008.pdf, Stormwater Quarterly Inspection 2009.pdf)

(d) Annual comprehensive site evaluations (Stormwater Comprehensive Eval Summary 2005.pdf,  

Stormwater Comprehensive Eval Summary 2006.pdf, Stormwater Comprehensive Eval Summary

2007.pdf, Stormwater Comprehensive Eval Summary 2008.pdf, Stormwater Comprehensive Eval

Summary 2009.pdf)

11. Describe any groundwater monitoring system in place at the facility.  Provide any groundwater

sampling and analysis plans, groundwater monitoring results that detected releases of

hazardous constituents, and corrective actions taken in response to groundwater contamination.  

Identify the location of groundwater monitoring wells, both active and inactive, on the map

provided in response to request #2.

The Urquhart Stations NPDES Permit contains requirements for five groundwater wells located

adjacent to the two low volume waste ponds and the coal pile runoff pond that treat and store coal

combustion by‐products. These wells are sampled semi‐annually. The plant also has eleven wells

associated with its ash landfill that are sampled semi‐annually. The wells are sampled per the

attached Groundwater Sampling and Analysis Plans. Also attached are groundwater sampling

results that have exceeded groundwater limits and a ground water monitoring well location map.

Corrective actions to minimize arsenic contamination have included the sale of fly ash to cement

manufacturers in lieu of ash pond disposal.

Please see attached:
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Urquhart Station

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(a) Groundwater Sampling and Analysis Plan (20100618103115652.pdf)

(b) Groundwater Monitoring Plan (20100618102944248.pdf)

(c) Groundwater monitoring well locations (20100618101711972.pdf)

(d) Groundwater monitoring well limit exceptions (20100618102745708.pdf)

(e) Groundwater quality and hydrogeological assessment (Urquhart Assessment Report

0610_FINAL1.pdf)

(f) Certification of adequacy of groundwater monitoring system (Urw Surf Aq Char 0809 Final.pdf)

12. Describe any known spills or releases to groundwater from each management area within the

last ten (10) years.

There have been no known spills or releases to groundwater from Urquhart Station.  

13. For each management area, identify any seepage flows, as well as their origins, flow paths, and

destinations.  Indicate the location of these flows on the map provided in response to request #2.  

Provide any reports or documentation with sampling results and/or information about the

volumes of these seepage flows from the last five (5) years.

No seeps have been detected on the ash pond dike.  Please see attached ash pond dike assessments

(Dike Landfill Pond Inspections 2005.pdf, Dike Landfill Pond Inspections 2006.pdf, Dike Landfill Pond

Inspections 2007.pdf, Dike Landfill Pond Inspections 2008.pdf, Dike Landfill Pond Inspections 2009.pdf)

14. Provide any hydrological studies conducted at the facility within the last five (5) years.

Please see Urquhart Groundwater Quality and Hydrogeological Assessment in response 11(e) and 11(f)

above.

15. Identify any known drinking water wells within a five (5) mile radius of the facility’s outer

boundaries.  Provide any monitoring or sampling results that demonstrate hazardous

constituents present within these wells.

There are no known hazardous constituents in the drinking water wells within a five mile radius of

the plant.  There is no known monitoring or sampling of the wells within a five mile radius of the

plant.  Attached are a map (URQUHART 5 MILE MAP.pdf) and a spreadsheet (Coastal_Plain_wells‐

1.xls) with water well information.  The information is from two different sources and does not

match.  The local Department of Health and Environmental Control (DHEC) has the following

disclaimer on its information:

“Disclaimer: The SCDNR does not guarantee the accuracy of this well information. In many cases,

our well information comes from old records, and as a result, some of the information, such as the
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Urquhart Station

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well owner or the well use, may no longer be accurate. This is in no way a complete inventory of all

the water wells in the South Carolina Coastal Plain.”

16. Describe the cooling system at the facility.  If applicable, submit the source of water withdrawn

and the amount of water withdrawn in gallons per day.  If applicable, describe the cooling water

intake backwash system and identify the individual backwash flows, the volume and the

discharge points for each flow.  Submit any sampling results of the backwash.

Except for the “other cooling systems” listed below, Urquhart Station utilizes a once‐through cooling

system.  Cooling water is withdrawn from the Savannah River and discharged to the Savannah River.  

The usage depends upon the number of generating units in service, and could range from 0 gallons per

day to about 190,000,000 gallons per day.

The intake system includes a mechanically raked trash rack at the river intake structure, and further

inland, another set of mechanically raked trash racks followed by traveling water screens.  Large debris

raked from the trash racks is loaded into trucks and disposed of on site.  Small debris raked from the

trash racks is sluiced to the cooling system discharge tunnel and returned to the river.  Debris collected

on the traveling water screens is flushed from the screens by fixed spray nozzles, sluiced to the cooling

system discharge tunnel, and returned to the river.  The backwash flow which includes sluice water and

traveling screen spray water is approximately 1050 gallons per minute.  The volume depends on the

amount of debris in the river, and could range from about 15,000 gallons per day to perhaps 125,000

gallons per day.

Sampling of the backwash was performed 16 times between September 1976 and June 1977 in order to

evaluate intake screen impingement of aquatic organisms.  A copy of the 316(b) Demonstration report is

attached.  

Other cooling systems:

• Simple cycle gas turbines designated as GT1, GT2 and GT3 utilize air cooling.

• Simple cycle gas turbine designated as GT4 utilizes a cooling tower for component cooling and

for inlet air cooling.  Cooling tower makeup is from the main plant’s once‐through cooling

system.

Combined cycle gas turbines designated as GT5 and GT6 utilize a cooling tower for component cooling

and a separate cooling tower for inlet air cooling.  Cooling tower makeup is from the main plant’s once

through cooling system.

See attached:

   

a) 316(b) Demonstration report (fish impingement) (Urquhart 316b Demo June 1977.pdf)

b) Urquhart water usage reports (20100617074007985.pdf)  
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17. Provide analyses performed on slope stability, inflow design floods, or dam breaks for any of the

management areas within the last five (5) years.

There have been no analyses performed on slope stability, inflow design floods, or dam breaks

for any of the management areas.

Sources of Responses

Name Position Title Questions Answered

Mark Ferguson Corporate Environmental

Services

Environmental Specialist 5, 9, 10   

Jean Claude Younan Corporate Environmental

Services

Associate Engineer 2, 3, 4, 5, 14, 15, 17

Ralph M. Webb Fossil/Hydro Compliance Senior Engineer 2, 7, 8, 9, 11, 12, 16

Suzette Mangan Corporate Fossil/Hydro Engineer 5, 6, 7

David Jerome   Urquhart Station   Plant Manager 3, 5, 7, 8, 9, 10,13,16