Clean Air  

BREDL's Comments on Duke Energy's Riverbend and Dan River Title V power plant permits

These are the first two NC Title V power plant permits to be offered for public comment:

Riverbend Steam Station
Facility ID: 3600040
Mount Holly, Gaston County, NC
Draft Permit No. 03788T21

Dan River Steam Station
Facility ID: 790015
Eden, Rockingham County, NC
Draft Permit No. 03455T15

Below is an outline of our comments on these two plants.  Duke Energy's Riverbend and Dan River plants reported criteria pollutants emissions over 31 thousand tons per year from the burning of coal, oil, and natural gas.

NOx 4,361 tons/year 2,687 tons/year
PM-10  152 tons/year 106 tons/year
SO2 16,475 tons/year 7,877 tons/year
source: EPA TRI 1996

Some specifics on the draft permits

1) Current Trimming

On April 3rd we submitted documents which prove that Duke is using and has used for an unknown period of time software which ramps down the voltage on the electrostatic precipitators (ESPs) at their fossil-fueled plants.  This practice known as "current trimming" keys voltage levels to opacity levels.  This practice is dangerous and must be prohibited.  The reasons are a) the plants should be considered in violation of particulate emission standards with ESPs used at less efficiency than in stack testing; b) opacity is unrelated to particulate emissions; c) current trimming violates the general duty clause to use pollution control devices at peak efficiency; d) current trimming software should trigger NSPS; e) current trimming has enormous impacts on PSD; and f) DAQ cannot permit a continuing violation.  Current trimming is a fatal flaw in these draft permits.  This practice alone should yield to permit denial.

2) Sulfur Dioxide

The 24-hour health-based NAAQS (National Ambient Air Quality Standard) for sulfur dioxide is 140 ppb but poor atmospheric mixing and air inversions can increase concentrations in populated areas to dangerous levels in a matter of hours. The risk to the very young, the elderly, and to people with heart or lung disease is especially serious.  Our file searches at the DAQ reveal continuous violations of existing NAAQS at both plants.

The Dan River plant exceeded the 24-hour SO2 NAAQS in 1998 and 1999:
3/10/98--178 ppb
3/11/99--158 ppb
4/12/99--302 ppb
4/12/99--524, 569, 613 ppb (3 hour standard)

The Riverbend plant also violated SO2 NAAQS:
5/2/94--165 ppb
10/4/96--160 ppb
11/15/96--152 ppb

Tests for ambient levels of SO2 at Riverbend were conducted by the company from 10/1/93 to 12/1/96.  Similar tests at Dan River commenced on 1/30/98 and will continue until 36 months of data is collected.  No assurances to do better by Duke Power can outweigh the facts of monitored
excess emissions throughout the 3-year testing period and which continue to the present time.

3) Nitrogen Oxides

The draft permits contain the NOx limit of 1.8 lb/MMBtu for 4 Riverbend and 3 Dan River coal-fired units.  We can assume that these plants operate for 8760 hours per year, which would result in annual NOx emissions of 90,192,960 pounds (45,096 tons) for Riverbend and 62,914,320 pounds (31,457 tons) for Dan River's coal-fired boilers. These totals are roughly ten times the EPA Toxic Release Inventory annual plantwide NOx emissions. Duke's  Riverbend application itself lists annual NOx emissions from Units 4,5,6,7 (ES-1,-2,-3,-4) at  28,640,400 (14,320.2 tons/year). The Riverbend draft permit contains higher limits than the application estimates.  Both  application's estimates of  criteria emissions from coal-burning  may be incorrect.  They must be revised.

4) Visible Emissions

Duke Energy is out of compliance with state and federal visible emission regulations.  The 1999 Special Order by Consent allows Duke Energy Corporation to delay until 2002 compliance  with existing visible emission regulations at coal-fired facilities including Riverbend and Dan River. The references to the SOC in the Title V draft permits fail to justify Duke's non-compliance. The regulations which the company sought relief from include 15A NCAC 2D .0521 "Control of Visible Emissions,"  which became effective on February 1, 1976.  For 56 days a year, each plant may exceed the six-minute visible emission standard at up to 100% opacity under the formula prescribed in the Duke Energy SOC.  For nearly one-sixth of total operation time most of the coal-fired plants in the state could emit pollutants which would blacken the sky.

Duke Energy stipulates in their SOC that the company is in violation of 15A NCAC 2D .0521 Control of Visible Emissions.  "The COMPANY has discharged and continues to have the potential to discharge visible emissions to the excess of the Visible Emissions Standard."  (SOC paragraph 1.D)

5) Toxic Air Pollutant Procedures

The permit allows the burning of mineral oil containing polychlorinated biphenyls (PCB).  The draft permit states that total PCB content shall not exceed 500 ppm and that,  "b. Total maximum boiler injection rate shall not exceed 10 percent (on a volume basis) of the total fuel feed rate." Although mineral oil may be burned at only one unit at a time, under this permit the total fuel feed rate volume will determine PCB concentration, i.e. PCB's could amount to 50 ppm of the total fuel volume, oil, coal, and natural gas combined.  In the permit application for Riverbend, Duke calculates the potential fuel use at 26,294,848 MCF of natural gas,  3,977,842,414 pounds of coal, and 229,094,604 gallons on fuel oil.  Also, the application states that, "PCBs have their chlorine-carbon bonds destroyed in the boilers and generate HCl emissions."  This is incorrect because it is only partly true.  The bonds are temporarily destroyed but dioxins and furans are formed after these elements are emitted from the boiler in the stack when temperatures fall below 800 degrees.

A Toxics Release Inventory (TRI) is now required annually by the Environmental Protection Agency for all coal-fired electric generating stations.  In 1998 Duke Energy's seven coal fired steam stations emitted approximately 22 million pounds of toxic compounds.  These emissions result from the burning of thousands of tons of coal.  The releases include hydrochloric acid, sulfuric acid, hydrofluoric acid, barium, manganese, copper, chromium, zinc, arsenic, nickel, ammonia, beryllium, chlorine, cobalt, lead, selenium, mercury, and dioxin.  Airborne particulates consist of 1) solids which adsorb hazardous air pollutants, and 2) droplets of liquid pollutants including volatile organic compounds.  Approximately 80% of the TRI compounds listed by Duke is airborne pollution.  Visible or invisible, it is a toxic whirlwind which must be reduced. Our initial review of Duke's permit application indicates the draft permit fails to adequately control hazardous air pollutants.

Janet and Lou Zeller
April 5, 2000

Title V Fact Sheet
BREDL comments on other Title V permits