Water Pollution Control Facility_Van Drie LetterJune 27, 2008
Mr. Kevin S. Firnstahl
Assistant city Clerk
City of Dubuque
City Hall
50 West 13~' Street
Dubuque, IA 52001-4864
Deaz Mr. Kevin S. Firnstahl:
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i!$ JUt~ 30 P~ 2~ 45
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D~;~u ~.~e, IA
Included in this mailing are 8 CDs for distribution to Mayor Roy Buol, City Council, and
City Manager Michael Van Milligen. Please provide these CDs to them plus copies of the
enclosed 3-page letter of date June 26, 2008 and copies of the email of Jonathan Brown
to me of date 9-OS-2000, and a copy of page 175 of the Water Pollution Control Plant that
refers to Plant Operations and Maintenance.
Many thanks for your courtesies,
~~~~
Gerhazdt Van Drie, R.C.E.
June 26, 2008
Oa JU~~ 30 Pik 2~ 45
The Honorable Mayor Roy D. Buol and members of the City Council City' CI~i+~:~S ~ffiCe
City of Dubuque
City Hall Dt~bu~~~' I~
50 West 13~` Street
Dubuque, IA 52001-4864
Dear Mayor Roy Buol and City Council Members:
I have sent to Mr. Kevin Firmstahl, Assistant City Clerk various documents to forward to
all of you for information purposes pertaining to the decision making that you will need
to make pertaining to the operation of the Water Pollution Control Plant (WPCP) and
sludge disposal, and to the need for raising sewage fees for payment of capital
improvements and increased operational costs of as much as 50 to 55 percent as
presented in the new Facilities Plan (FP). Also included is a CD showing in operation a
portable test tank with Van Drie mixers and a full sized 30-foot long mixer beam with
attached mixer plates in operation exactly of the size that can be used in the reactor tanks
at the WPCP.
Included herewith are 2 documents that are very important to you. One shows the results
of 2 excellent test runs of the Van Drie technology at the WPCP and the second
document a copy from a WPCP annual budget report showing the weight of sludge
incinerated every day and the weight of added polymer chemical used for dewatering that
sludge every day.
It is important that you have the following information items clearly in mind:
1. The existing 3 reactor tank trains at the WPCP each have 9 openings where 9
electric mixers are installed in deck openings that are 30 feet apart. 4 Van Drie
mixer pairs with 30-foot long beams can be installed in each train in the same
deck openings.
2. The existing decks do not have to be removed in order to install the Van Drie
mixers in the existing reactor trains.
3. The Van Drie sewage treatment objective is to reduce the amount of organic
solids of sludge at the WPCP with aerobic microbes in the workhorses of the
activated sludge process, which are the reactors, within hours instead of 15 to 30
days as with anaerobic microbe digesters.
4. In order to place as much organic solids into the reactors as possible, mechanical
removal of settleable solids with primary clarifiers should be eliminated from the
process. Eliminating the operation of primary clarifiers is a huge cost savings.
5. Chemical companys have favored the use of what is known as "Advanced
Primary" treatment. This innovation consists merely of dumping more chemicals
into the primary clarifier influent in order to settle out more solids.
6. The drafters of the new Facilities Plan (FP) take issue with the amount of primary
sludge reportedly settled out with the primary clarifiers at the WPCP. The
question then is, how much chemical is presently being induced into the primary
clarifier influent at the WPCP? If so, the questions now are, how much and what
is the cost? The FP is silent about inducing chemicals into the primary clarifier
influent.
7. The FP is also silent on the amount of high purity oxygen (HPO) that has been
actually used in the operation of the existing reactors. They cite design criteria for
future operation projections instead. Also the FP is silent on the amount of HPO
that is vented out of the head space at the end of each train and is lost to the air
instead of being used by the microbes. If HPO is induced under pressure then a
vent has to be included at the end to keep from blowing off the decks of the
reactors.
8. Aerobic microbes breathe in oxygen and expel CO2 as humans do. From the first
of 9 stages to the last, CO2 collects in the headspace above the sewage being
treated and below the deck, which dilutes the HPO so it does not transfer into the
liquid sewage as efficiently in each succeeding stage. Thorough mixing becomes
very important in order to make use of the entire volume of the reactor tanks for
bringing a large amount of microbes, HPO, and organic matter together. With the
Van Drie mixers installed in deck openings, the problem of getting rid of the CO2
is assisted and with it the problem with ph. Also, nutrient removal can be
implemented herewith.
9. Reducing the amount of final sludge quantities to be removed from the WPCP to
the largest degree at a reasonable cost can be best accomplished with use of the
Van Drie mixers and HPO input with diffusers or spargers. With this technology
the longest possible exposure time for oxygen transfer to the liquid sewage is
accomplished.
10. The WPCP permit with the Iowa Department of Natural Resources (DNR) has
been expired for several years. The time frame for completion of the
recommended capital improvements according to the FP is January 2013.
11. The installation of the Van Drie mixers in the unused reactor train can be
completed in 6 months without interference to plant operation. When viewing the
CD it is obvious that installing 30-foot mixer pairs can be easy to do at the
WPCP.
12. Reducing the final sludge quantities at the WPCP reduces the amount needed to
be disposed of off-site.
13. The operating problems of sludge hauling to land sites are identical for the land
spreading options that the staff is proposing as to what the Van Drie Trenching
Process proposes. The difference is that with the Van Drie technology the sludge
is placed in an excavated trench with the excavated soil immediately available for
daily cover which thereby making it inaccessible to vectors, people, and rainfall
runoff. The staff proposes spreading it on land where the sludge is accessible to
all vectors, animals, and rainfall runoff that contaminates streams and the
Mississippi River. Land spreading also is known to contaminate food crops which
can lead to lawsuit claims from consumers. Odor complaints from neighbors are a
common problem with land spreading.
14. The cost estimates by the staff for land spreading are very high as compared with
trenching. Spending $7000 per month for land spreading rights amounts to
$84,000 dollars per year and $1,680,000 fora 20-year time frame.160 acres of
land can be purchased for about $750,000 dollars and could provide enough
sludge disposal trench volume for 40 years. Choosing trench disposal vs. land
spreading of sludge is an easy decision for the City Council to make. Trench
disposal is ayear-round, all-weather possible operation. No storage of sludge is
necessary as when scheduling around planting and harvesting of crops as with the
option of spreading sludge on crop land.
The Final Report shows a considerable amount of uncertainty pertaining to the siting and
performance of anaerobic digesters at the WPCP. Since the Van Drie technology can
reduce the amount of fmal sludge quantities at the WPCP and is appropriate for all
disposal options, it makes sense to immediately install this technology into one of the
unused aerobic reactor trains for a cost estimated at $600,000.
Today's news reports that the cost of gasoline will be $7 dollars a gallon 3 years from
now. The Van Drie HPO Activated sludge Process uses the forces of buoyancy and
gravity for mixing liquid and slurries. This is GREEN POWER. Each 30-foot long
beam and mixer pair is controlled with a 3/ HP electric motor. 4 miter pairs = 3 HP.
This can be supplied with solar when the power is off to the plant. You can see a full
size unit in operation on the CD.
Respectfully,
c~~/~~
Gerhardt Van Drie, R.C.E.
FY 2001
PERFORMANCE MEASURES ACTUAL
!Tons of sludge incinerated/day ,
FY 2002 ': FY 2003
ACTUAL BUDGET
FY 2003 FY 2004
REVISED RECOM'D
5.72 6.40 5.72
4.88 5.17 4.88
1 ~ ' ~~ ' ~ ' ~~ ,
9,760 10,340 9,760
Pnmary 10.00
;.. Secondary 8.00
"hounds of secondary
~
sludge processed per day 16,500
~ Average electrical demand
,
(~M 900
Average fuel
usage(gailons/day) 250
`, Average power factor (plant) 80%
.Average polymer usage ~~ .
-~ pounds/day of operation) ~
-- 5,703
Average chlorine usage
(pounds per day) April 1 to
October 31 250
Average percent BOD"
removal 95
Average percent SS''* removal 90
850 , 900
540 250
83% 80%
4,821 ~` ~ ,300
250 250
96 , ~ 95
90 92
850
250
83%
5,300
250
96
90
5.72
_}
9, 760 , ,
850 '
250 '
83%
5,276 '
250
96
90 ,
BOD -Biochemical Oxygen Demand is a measure of the oxygen consumed as
pollutants in a sample are broken down through natural biological processes '
over the course of five days.
'"* SS -Suspended Solids is the residue retained on a glass fibre filter after a known ,
sample is filtered across the glass fibre.
'** Polymer for Fiscal Year 2001, Fiscal Year 2002, Fiscal Year 2003, and proposed ,
Fiscal Year 2004 are based on liquid mannich polymer ;~
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Water Pollution Control Plant Plant Operations and Maintenance '
-175-
Subj: Data
Date: 09/05/2000 9:22:33 AM Pacific Daylight Time
From: BROWDAHL
To: GVanDrie
Tried fa~ang but it wouldn't go through so I am sending this email with data.
8/23/2000 CBOD TSS NH3 N MLSS
9:30 110 64 35.2 4410
10:30 9 20 22.1
11:30 12 21.1
12:30 5 10 18.8
13:30 18.5
8/24
primary 124 96
10:00 39 59 33.8 6500
11:00 9 16 30.0
12:00 28.0
13:00 3 5 25.6
14:00 24.8
all results in mg/L
We had some problems with TP, hopefuly we should be able to complete these this week. 1 included data for primary for the
second run for your information. The initial BOD far that run seemed tow, perhaps there was additional treatment being
completed while sampling and testing was in progress. Something that could be looked art is th stop all biological activity at the
time of sampling, especially initial sample grabs. I found the ammonia results interesting in that the ammonia reduction and
BOD reduction are going on simultaneously. I wiA send you this report by mail also.
Best Regards,
Jonathan R. Brown
Chemist, City of Dubuque WPCP
Class of '72'
2 ~ac~lw4na-