Document ID: EPA-HQ-OW-2006-0771-1482
Agency: epa
Document Type: Supporting & Related Material
Title: 
Posted Date: 2008-09-15T04:00Z

Steam Electric Data Request Follow-Up Questions

Project Name:  Steam Electric Detailed Study

	Project No.:  0172.04.022.041

Company Name:  Georgia Power

	Contact Name:  William R. Evans

Plant Name:  Plant Bowen	Contact Phone Number: 404-506-7031

or Email Address:  wrevans@southernco.com

ERG Staff (or ERG Rep) Name: Sarah Holman

Company Affiliation: ERG	Date: 12/19/07

This document contains CBI:   ___  Yes     x      No

	Type of  Contact:     x      Email       x    Telephone           

General Subject:  Data Request Assistance / Follow-Up 

Follow-Up Question Number	CBI =

Yes (Y)

No (N)	Data Request Question Number	Data Request Page Number	

Question/Answer

1	N	8	B-3	Q: “Total Unit Production in 2006” provided for Unit 1 is
exactly the same as the production provided for Unit 4.  Please confirm
these production values.

A:  The value provided for Unit 4 is correct.  The value for Unit 1
should be 4,905,203 MW-hr.

2	N	11	B-8	Q: Frequency of drainage from coal pile is given as 365 days.
 Does the plant have an estimation of the actual number of days of
drainage from the coal pile, or an estimation of the number of days of
rain in 2006?

A:  The plant does not have a record of the number of days of rain in
2006.  The plant estimated the amount/frequency of drainage from the
coal pile as that pumped out of the coal pile runoff pond.

3	N	16	B-10	Q: “Type of Fly Ash Handling System” is listed as both
wet and dry.  What is the approximate percentage of the time that the
fly ash is handled in a dry fashion?

A:  98% of fly ash is handled dry and sold.  Fly ash is only sluiced
when units are started up or during periods of maintenance.  The tpd of
fly ash produced accounts for fly ash handled wet and dry.  Mr. Evans
will follow up with the plant to determine the frequency of the ash
sluice.

4	N	16	B-10	Q: “Percent Contribution of Source to Sluice Water Flow”
is listed as 100% FAS and 0% IN-Makeup for each of the four units.  Does
this indicate that during some years, IN-Makeup is used to make up for
water loss, but this was not necessary in 2006?  

A: Yes.  In 2006, enough rain water entered the ash pond that the plant
did not need to use makeup water for the fly ash sluice.

5	N	31	B-21	Q: Why was wastewater generated from the Units 2 and 3 air
pre-heaters, but not from the Units 1 and 4 air pre-heaters in 2006?

A: Air pre-heater cleaning was not necessary for Units 1 and 4 in 2006. 
Typically, the air pre-heaters are only washed when the units are
brought down and that typically occurs every three to four years.

 

6	N	35	B-24	Q: The plant responded that each of the cooling systems came
online several months before their respective steam electric units. 
Please confirm these dates.

A:  Confirmed.  The cooling systems came online before the steam
electric units for pre-operational tests.

7	N	43	B-26	Q: Outfalls 01D – 01G, 03A, 03D, 03G, and 04-08 are not
listed in Table 14 or the process diagrams.  Did they discharge in 2006?

A:  See attached table.

8	N	47	B-28	Q: On Diagram 5-1, the flow rate presented for PMRS is 9
gpm, whereas in Question 13, the PMRS flow rate provided is 4 gpm. 
Please explain the difference.  Which flow rate is more accurate?

A:  The flow rate provided in Question 13 (4 gpm) is more accurate.  It
is based on amount of pyrites in the total amount of ash produced in
2006.  The flow rate presented in Diagram 5-1 is a “hybrid” flow
rate calculated to balance the water flow rates.

9	N	47	B-28	Q: On Diagram 5-1, the flow rate presented for FAS is
720,000 gpd, whereas in Question 16, the FAS flow rate provided is
3,240,000 gpd.  Please explain the difference.  Which flow rate is more
accurate?

A:  Mr. Evans will follow up with the plant to resolve the discrepancy
(relates to new information in number 3).

10	N	47	B-28	Q: Each BAS flow rate in Table 6 is roughly equal to the
BAS flow rate listed in the Diagram 5-1. Please confirm the BAS flow
rates for individual units and the total BAS flow rate? 

A:  The BAS flow rates in Table 6 are correct.

11	N	47	B-28	Q: Please confirm that hydrobins are used to remove solids
from the bottom ash and fly ash sluice systems (Diagram 5-1 shows solids
removal hydrobins for the bottom ash and fly ash sluice systems;
however, the plant’s response to Table 7 indicates that there is no
solids removal or solid waste disposal).   How many hydrobins are used
for the bottom ash sluice and fly ash sluice systems?

What is the amount of wastewater overflow from solids removal?  For the
fly ash sluice system, how are solid wastes disposed?  For the bottom
ash sluice system, please confirm that the solid waste is sold without
further treatment (550 tpd).

A:  What the plant refers to as “hydrobins” are actually areas of
the ash pond (“burmed areas”) in which the ash is dewatered.  Water
from these dewatering areas flows into the “recycle pond area” of
the pond for removal of the ash fines.  Approximately 99% of the solids
removal occurs in the dewatering areas.  The plant uses tractors to
remove the ash from the dewatering areas.  Dredging is not necessary.

12	N	47	B-28	Q: The CTB flow rates on Diagram 5-1, in Table 16, and in
Table 12 are significantly different.  Please explain the difference. 
Which flow rate is more accurate?

A: The flow rates provided in Table 12 are most accurate and are based
on generation-weighted allocations.  The flow rates provided in Diagram
5-1 and Table 16 were calculated to balance the flow rates.  The CTB
duration should be 18 hpd in Table 12 because the CTB is shut off for
about ¼ of the time.  

13	N	47	B-28	Q: Regarding Diagram 5-1, please confirm that no wastewater
treatment occurs in the Mixing Basin or the Low Volume Waste Basin.

 

A:  Confirmed.

14	N	47	B-28	Q: For WWT-1 (Diagram 5-1), please confirm that pH
adjustment occurs within (as part of) the ash pond and not within a
separate tank/pond as indicated in the diagram.  

A:  Confirmed.  pH is adjusted within the “recycle pond area” of the
ash pond.

15	N	47	B-28	Q: For WWT-1 (Diagram 5-1), please provide the flow rate
breakout for “RECYC – FAS/BAS” (7,000 gpm) for the following: BAS,
FAS, PMRS, and miscellaneous process recycle. 

A:  These recycle flow rates are essentially the same as the individual
flows entering the ash pond.  

16	N	47	B-28	Q: Please clarify whether the WWT-2 unit is a settling pond
(as shown on Diagram 5-2) or a settling tank (as listed in Table 17). 
Please confirm that pH adjustment and chemical precipitation occur
within the WWT-2 unit and not within separate vessels as shown on the
diagram?   

What chemicals are typically added to the WWT-2 unit for chemical
precipitation?  Were any of these chemicals added in 2006 (none are
listed in Question 51)? 

A:  WWT-2 was a settling pond, but was dug up/removed in either late
2005 or early 2006.  WWT-2 was not in operation in 2006.  The plant
listed a settling tank in Table 17 to indicate the plans for future,
temporary settling if necessary.  

17	N	47	B-28	Q: Why does the plant send effluent from the sewage
treatment plant to the WWT-4 settling pond?

A:  The sewage treatment plant is a package-type plant that could
discharge directly to the river, but the Georgia Power plants prefer to
send wastewaters through a “buffer”, such as a settling pond, to
ensure that permit limits are met.  The WWT-4 settling pond effluent is
limited for BOD because it receives sewage treatment plant effluent.  

18	N	47	B-28	Q: Diagram 5-3 shows an effluent flow rate from WWT-4 of
~7,000 gallons (10 dpy), whereas Table 19 lists an effluent flow rate of
10 gpm, 12 hpd, 12 dpy.  Please explain the difference.  Which flow rate
is more accurate?

A:  Table 19 is more accurate for 2006.

19	N	48	B-31	Q: The reverse osmosis concentrate shown on Diagram 5-1 is
not listed as an untreated wastewater in Table 16.  Please confirm that
the reverse osmosis concentrate is not treated and should be included in
Table 16.

A:  Confirmed.  The flow of reverse osmosis concentrate is continuous.

20	N	51	B-33	Q: For WWT-1, the “Average Dose Concentration” of lime
is listed as “As required to maintain pH in discharge above 6.0”. 
As requested in EPA’s email to UWAG on 7/11/07, please provide the
concentration of the active ingredient added (i.e., the amount of active
ingredient contained in the chemical product).

A:  100% calcium carbonate.

21	N	52	B-34	Q: For WWT-1, did FAS, BAS, and PMRS enter the ash pond 24
hpd and 365 dpy?  Was the recycle from the ash pond used for RECYC-FAS,
RECYC-BAS, RECYC-PMRS, and miscellaneous recycle 24 hpd and 365 dpy?

A:  Yes, 24 hpd and 365 dpy for BAS and PMRS.

22	N	53	B-35	This information has been removed because it contains
confidential business information (CBI) per 40 CFR Part 2, Subpart B. 
This information can be found in the confidential record.

23	N	53	B-35	Q: Question 53 is marked as CBI for WWT-1, but is not
marked as CBI for WWT-2, WWT-3, or WWT-4.  We have treated all WWT costs
as CBI.  Please confirm that we should continue to do so.

A:  Confirmed.