09-17-1985 (City Council) Agenda Packet ', . /6 / ?
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AGENDA
SPECIAL WORK SESSION
CITY COUNCIL, CITY OF WYLIE, TEXAS
TUESDAY , SEPTEMBER 17 , 1985
7 :00 P.M. LIBRARY WORK ROOM
800 THOMAS STREET
CALL TO ORDER
ORDER OF PAGE
BUSINESS REFERENCE BUSINESS
1 Work session with representatives
of the North Texas Municipal Water
District to discuss current and
future sewer plant .
2 ADJOURN
TO : CITY COUNCIL
FROM: CITY MANAGER
DATE: SEPTEMBER 17 , 1985
SUBJECT: NTMW'"' S OPERATIONS CONTRACT FOR WYLIE
WASTEWATER TREATMENT PLANT
It is the considered conclusion of the City staff to
recommend to the City Council that the City of Wylie end
it ' s contract for operations with North Texas Municipal
Water District for the operation of the Wylie wastewater
treatment plant and that we begin in October to search for
an engineering firm to begin preparation of plans and
licensing procedures for the construction of a new plant of
approximately three (3) million plus gallons per day to an
advance secondary treatment level. Further, that we begin
to take the financial steps necessary to issue water and
sewer revenue bonds in the amount necessary to complete the
construction of the new plant. We have come to these
conclusions for the following reasons :
1 . Our investigation into the perceived advantages of
NTMWD bond rates over what the City can get on
it ' s own has proven that no difference in the
rates actually exists. NTMWD does not pledge any
assets or revenue of their own. Bonds for any
project done within a city by NTMWD are issued on
, whatever bond rating that particular city can
generate on it ' s own. This fact has been proven
by recent issues done in Rockwall which is
currently under construction through NTMWD.
2 . While NTMWD' s reputation in water is outstanding
and their sewage treatment solutions where
regional problems exist has been commendable ,
there does not exist a regional solution in
Wylie' s situation . Rowlett and Sachse send their
sewage to Garland . Murphy and probably Lucas will
eventually join into the regional plant built
primarily for Richardson , Plano , McKinney and
Allen. That leaves the City of Wylie in an island
unto itself both by isolation of prior plants
and by topography . Only St . Paul remains
unsettled and obviously , Wylie is trying to do
something about that problem currently .
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3 . Unlike other localities , we already own a plant
and land and have additional land, ideally
located , upon which a new facility can be built .
In addition , we , unlike other cities , have had the
foresight to collect impact fees and begin a lift
station program, all of which places us in an
ideal economic position to solve our own problems .
4 . We either have currently on staff or will have
within the near future , as a result of the demands
of growth, sufficient highly licensed personnel as
well as our own internal engineering and finance
staff . The City currently has among personnel
working as of 9/17/85 the following State of Texas
licensed certified operators : 1"A" water ; 3 "C"
water ; 1 "B" wastewater ; 1 "C" wastewater and 3
"D" wastewater .
5. The site of the proposed plant is within 50 ft . of
the proposed site for the new Public Works
Complex. Therefore , management of the wastewater
plant can be done very efficiently by our existing
public works administration staff . To have
another plant which we do not operate that close
to our supervisors with a chain and lock on it and
with the citizens complaining to us without any
operational control seems , on the very face of it ,
ludicrous .
6., There seems no reason to delay the decision. The
staff considered whether or not we should work
under the current arrangement until the new plant
is built . The recent report we received from the
Texas Department of Water Resources is a clear
indication to us that until we become involved in
the plant , we cannot fully develop our own staff
nor move up to the responsibility implied by
holding the permit to treat wastewater . You
should remember that the permit is in the City of
Wylie ' s name and we are the responsible party . We
are the ones who will be sued and under NTMWD' s
contract we are the ones who will pay directly for
any major repairs . If we go ahead now and break
the tie between us and NTMWD , we will have time to
acquire and train people in the operation and
maintenance of the sewage treatment plant . These
same people will then be involved from the ground
up in the construction of the new plant .
7 . The question has been asked , will we save money?
The answer is an unqualified yes . First , we will
only pay for one administration . Second , we will
know the exact costs and what they are for rather
than being the victim of NTMWD' s overhead spread
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among it ' s various contracting agencies . We will
be able to control our own costs and will have the
ability to have on our payroll additional
personnel which we can use from time to time on
other projects . You must be aware that the staff
at NTMWD that is considered so outstanding is
made possible by contributions via contracts such
as this that are made to NTMWD. As we retain our
own operation responsibility , we can make the same
distribution of cost work for us internally . For
example , the cost of the engineering staff can be
partially defrayed by the sewer plant operation,
not to mention other equipment , buildings and
personnel . Another example is that in this year ' s
budget from NTMWD , we will be paying the total
cost for a new pick-up and a piece of lab
equipment . We will pay the total cost of these
pieces of equipment , but will receive only part of
their use .
8 . The staff is not supportive of the City retaining
the responsibility for a service in the minds of
the people without having the operational control
of that service . We see on a daily basis the
problems created by contracting away the trash
pick-up in the City of Wylie . In the long term
the benefits of our own operational control are
numerous . Most importantly , we will have the
ability to control our own destiny in terms of
, preparing for growth and taking advantage of cost
saving expenses as they occur . For one example ,
we don ' t pay our people as highly as NTMWD yet we
have the same certification levels. We can also
use slots that are created in the wastewater
department as either retention slots for older
employees or as training slots for new employees .
9 . We are further troubled by what we perceive to be
a dilemma of incentives . If the City operates the
plant , it must do so in a cost effective way and
in a way that , as much as possible , pleases it ' s
neighbors and protects it' s license for operation.
To that end , the City Council will hold the City
Manager responsible , who will in turn hold the
Director of Public Works responsible for the
successful operation of the plant . We believe
these to be clear and unclouded lines of
responsibility with motivational incentives
logically in place . On the other hand , if we
build the plant and indebt our citizens , retain
the legal obligation and yet give the operational
responsibility to North Texas where then are the
lines of responsibility? How can we effectively
make NTMWD do the job that the Council believe
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they should do . Where are the incentives for
constantly improving cost efficiency . The
operators of the plant will be encouraged to
increase their budget in order to insure their
promotability within the NTMWD system whereas City
personnel insure their promotability by decreasing
costs .
10 . When we contemplate spending 3-4 million dollars
to build a plant , we , the debtors , ought to be the
ones who make the decision about what kind of
plant we build . Under North Texas ' agreement , this
type of overview would be done almost exclusively
by them.
11 . The staff would like to point out to you that
while NTMWD' s reputation is well known , your own
City staff is becoming more and more known and
looked at with an ever increasing amount of
respect by sister cities in our area. While it
may have been true in the past that the City of
Wylie was not in a position to even contemplate
such an ambitious undertaking , those facts are no
longer true and will be even less true in the
future. These changes are not occurring simply
because of the wastewater treatment plant , they
are occurring because of the growth and the City ' s
ability to obtain and retain more and more highly
qualified and competent key staff personnel . The
, reputation of NTMWD did not simply occur , it was
created by design . We stand on the threshold of
the same phenomena . The success that NTMWD has
had in wastewater is not relative to a weakness of
other regional cities ' staffs , it is relative to
those cities ' inability to work with each other
and North Texas entering the picture as a mediator
to accomplish a solution where the parties could
not even talk to each other . Thus , we submit that
NTMWD' s ability as a mediator is probably the area
in which they should have the highest regard and
not simply as the operator of a sewage treatment
facility. Your staff would like to have the
opportunity to accept the responsibility . We see
no need for the mediator .
12 . Once the new plant is built , our initial
calculations indicate that operational efficiency
would be greater with the City than with contract
because there would be no overlapping
administrative overhead as well as a constant
monitoring and control of daily operational
expenses .
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13. If the City retains operational control of the
sewage treatment plant , we will know without any
intermediary agency , what the plant is doing on a
day to day basis . We will be better informed
about equipment that is beginning to function
marginally and thus will have a long lead time to
prepare for necessary expenditures . When
complaints arise , we will be better prepared to
explain what happened and to make operational
adjustments to control these problems .
14. Let us also make you aware of some small but
interesting facts . The wastewater permit is
issued in the name of the City of Wylie and the
City of Wylie is legally responsible for the
plant , it ' s operation , and the discharge which it
produces . We are also legally responsible for
insuring compliance with the requirements of the
permit. The licensed operator, held responsible
by the State of Texas for the wastewater
treatment plant for the City of Wylie is one Bill
Windham our Director of Public Works. Bill has a
"B" wastewater license and will soon acquire his
"A" license . In addition, your City Manager signs
the reports that go to the State about the quality
of effluent discharged from the plant . This
report is generated at NTMWD but cannot be signed
by anyone at that location because it is legally
our plant . These facts , it seems to the staff
highlight the facts that we conclude are most
illuminating to the problem. We have retained the
full responsibility for the plant , the legal
ramifications , financing , debt , repair and every
other logical responsibility of ownership and yet
have given up operational control . Our fate , that
may someday be called to task lies in the hands of
others .
15 . If we contract away the Wylie sewage treatment
plant , we would have a future concern about who
would control the ultimate disposition of the
sludge and treated effluent that is produced by
the plant . These two commodities have a future
potential of being a valuable resource .
Technology could make these two by-products of the
wastewater treatment process potentially large
scale revenue sources . We would certainly want
that income to return to the City of Wylie . Under
some forms of the possible agreements with NTMWD ,
we might lose the control of this resource .
All of the above comments have been discussed at length with
the major department heads of the City of Wylie . These
comments represent our basis for formulating the
5
recommendation that we no longer continue to contract
operations of the sewage treatment facility with NTMWD.
Further , we believe that we are perfectly capable of hiring
an engineering firm and bonding for the debt in exactly the
same method and means that NTMWD would use . They will rely
primarily on contract engineers for the design with their
people providing overview. We can do the same . In
addition , they will bond the debt probably through First
Southwest and we can certainly use the same process with
that firm. It is First Southwest , not NTMWD that gets the
bonds to the market and sold .
I trust that it is apparent that this recommendation is not
made lightly and that the staff has given a great deal of
thought as to the reasons for that recommendation. I
suggest that the fifteen ( 15) explanations of that position
that you see listed above fully explain our reasons for
reaching that conclusion . While we feel strongly that this
recommendation is in the best interest of the City of Wylie ,
we do not wish to imply that NTMWD was not the best choice
in past years . It is simply that we have matured as a
government and are now capable of shouldering the
operational aspects of the plant along with the legal
responsibility which we have always had . NTMWD can be proud
of it ' s record in the area of both water supply and
production . I and the rest of the staff are delighted that
the City of Wylie is a charter member of NTMWD ' s water
program. In addition , we could support a regional solution
to the sanitary landfill problem. However , while all of
these things might be true , they should not imply that it is
beyond the conceptual possibility that there might be some
things that are best done by the local government . We
believe that Wylie ' s short and long range interests with
regard to sewage treatment are best served at the local
government level by individuals who are directly responsible
to the City Council and to the citizens whom they serve .
Gus Papp s
GHP: bl
6
1985-86 ANNUAL BUDGET
SEWER SYSTEM
EXPENDITURE SUMMARY
13 WYLIE SEWER TREATMENT PLANT
1982-83 1983-84 1984-85 1985-86
ACTUAL ACTUAL AMENDED PROPOSED
PERSONAL SERVICES $ 9,600 $ 8,695 $ 9,687 $10,561
SUPPLIES 1,669 1,810 1,873 2,811
CONTRACTUAL SERVICES 27,569 26,812 27, 922 30,648
TOTAL EXPENSE: $38,838 $37,317 $39,482 $44,020
CAPITAL OUTLAY $ 664 $ 598 $ 3, 165 $ 1,051
TOTAL OPERATING
EXPENDITURES : $39,502 $37,915 $42,647 $45,071
DEBT SERVICE $ 9,609 $11, 163 $11,240 $10, 978
TOTAL DEBT SERVICE : $ 9,609 $11, 163 $11,240 $10,978
GRAND TOTAL: $49, 111 $49,078 $53,887 $56,049
FUNCTION
The City of Wylie owns a Wastewater Treatment Plant which is operated by contract by
the NTMWD. The plant has the capacity of 800, 000 gallons per day and is designed as an
oxidation ditch plant with sludge drying beds. The City of Wylie has a permit from the
TDWR #10384 which requires a basic 20 BOD and 20 TSS discharge into Muddy Creek
thence into Lake Ray Hubbard.
PROGRAM
The contractual agreement between the NTMWD and the City of Wylie requires the
NTMWD to provide total operation and maintenance of the plant including personnel,
supplies, and laboratory service. The plant is operated and inspected on a daily basis
with maintenance service personnel of the NTMWD available to back up the plant
operators. Also, the NTMWD has issued a series of revenue bonds to provide facilities for
the City of Wylie. During the coming year normal operation would be anticipated at this
plant.
- 36 - •
1985-86 ANNUAL BUDGET
SEWER SYSTEM
EXPENDITURE DETAIL
a3 WYLIE SEWER TREATMENT PLANT
1982-83 1983-84 1984-85 1985-86
ACTUAL ACTUAL AMENDED PROPOSED
PERSONAL SE::.‘ I . ES
02-t 3-OO -1010 ;Sup::"- r^vision $ 0 $ 2,319 $ 2,486 $ 2, 577
02-13-00-1030 Skilled 9,290 6, 171 6,827 7,595
02-13- 00-1050 Dye: 1 ime 310 205 374 389
TOTAL PERSONAL. SERVICES : $ 9,600 $ 8,695 $ 9,687 $10,561
SUPPLIES:
02-13-00-2030 Clothing Supplies $ 92 $ 23 , $ 11 $ 20
02-13-00-2060 Fuel, Oil & Lub. 196 404 363 562
02-13-00-2070 Machine Oil & Lub. 61 71 59 117
02-13-00-2080 Small Tools & Equip. 18 8 20 25
02-13-00-2081 Fire Extinguishers 0 21 0 0
02-13-00-2120 Chemical Supplies 1,276 1, 187 1, 100 2,000
02-13-00-2190 Vehicle Supplies 26 96 67 70
' 02-13-00-2300 Other Supplies 0 0 253 17
TOTAL SUPPLIES: $ 1,669 $ 1,810 $ 1,873 $ 2,811
CONTRACTUAL SERVICES :
02-13-00-3020 Worker's Comp. Ins. $ 290 $ 155 $ 379 $ 372
02-13-00-3030 Automotive Ins. 0 89 56 95
02-13-00-3060 Hospitalization 373 415 497 540
02-13-00-3070 Life Ins. 27 31 32 22
•
02-13-00-3071 Retirement 602 447 473 219
02-13-00-3080 Social Security 643 597 699 573
02-13-00-3090 General Liability 72 95 452 100
02-13-00-3110 Electric Power 14,010 15,080 15,789 17,50 1
02-13-00-3210 Vehicle Maint. 2 3 13 25
02-13-00-3280 Grounds Maint. 720 720 750 825
02-13-00-3300 Other Contractual Serv. 340 440 600 600
02-13-00-3310 Administration 2,233 1,661 1,996 2,277
02-13-00-3320 Supervision Serv. 0 0 0 0
02-13-00-3330 Maint. Serv. 7,057 4,953 3,971 5,000
02-13-00-3340 Laboratory Serv. 1,200 896 1,500 1,500
02-13-00-3390 Permits & Inspection Fees 0 1,230 1,200 1,000
02-13-00-3270 Radio Maintenance 0 0 12 0
TOTAL CONTRACTUAL
SERVICES: $27, 569 $26,812 $28,419 $30,648
TOTAL EXPENSE: $38,838 $37,317 $39,979 $44,020
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1985-86 ANNUAL BUDGET
SEWER SYSTEM
EXPENDITURE DETAIL
13 WYLIE SEWER TREATMENT PLANT
1982-83 1983-84 1984-85 1985-86
ACTUAL ACTUAL AMENDED PROPOSED
CAPITAL OUTLAY :
02-13-00-4030 Vehicle Equipment $ 664 $ 598 $ 623 $ 789
02-13-00-4060 Radios 0 0 0 0
02-13-00-4070 Non-Vehicle Equip. 0 0 2,542 262
TOTAL CAPITAL OUTLAY: $ 664 $ 598 $ 3,165 $ 1,051
TOTAL OPERATING
EXPENDITURES : $39,502 $37,915 $43,144 $45,071
DEBT SERVICE:
02-13-00-5060 Debt Service $ 9,609 $11, 163 $11,240 $10,978
TOTAL DEBT SERVICE: $ 9,609 $11, 163 $11,240 $10,978
GRAND TOTAL: $49, 111 $49,078 $54,384 $56,049
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4'7 Ar.
41110.
NORTH TEXAS MUNICIPAL WATER DISTRICT
P.O.DRAWER C
WYLIE,TEXAS 75098 REGIONAL SERVICE THROUGH UNITY
PHONE NO.442-5405
July 26, 1985
Mr. Gus Pappas
City Manager
of Wylie
P. O. Box 428
Wylie, Texas 75098
RE: Wastewater Treatment Plant
Operations
Dear Mr. Pappas:
From reviewing your letter of July 8 concerning the possibility of the
City terminating the operations contract with the NTMWD on the Wylie
Wastewater Treatment Plant, it became apparent that I had not fully
explained to you the NTMWD program nor the benefits accruing to the
City of Wylie. Therefore, I will take this opportunity to provide a
brief summary of the NTMWD program and the actual Wastewater
Treatment relationship with the City of Wylie in this letter. Then, I
hope we have the opportunity to visit and that I could answer any
questions which should develop a better understanding.
NTMWD WASTEWATER TREATMENT PROGRAM
In 1972 it became obvious that the Federal and State Authorities were
going to require substantial improvement in wastewater treatment with
protection of the lakes and streams from a water quality management
viewpoint. Eighteen cities and two counties urged the NTMWD to
become involved in wastewater treatment on a regional basis as well as
the traditional potable water service we were performing. The City of
Wylie was one of these municipalities.
After the NTMWD Board of Directors made the decision to become a
Regional Wastewater Treatment Operator a committee was established
composed of representatives from all of the major cities in the area to
develop a program which did include a representative from Wylie. From
this District Policy No. 10 was developed and was eventually approved
by the NTMWD Board of Directors. This policy provided for the
NTMWD to provide a broad area of service to the communities in an
attempt to provide better trained and educated personnel for
wastewater treatment service along with the necessary equipment and •
laboratory to assure adequate availability of technology in the area.
During this time the Texas Water Quality Board designated the NTMWD
•
Mr. Gus Pappas
City Manager
City of Wylie
July 26, 1985 - Page 2
as the Regional Wastewater Treatment Operator for the East Fork of
the Trinity River.
In 1985 the NTMWD owns and operates seven wastewater treatment
plants and operates seven wastewater treatment plants that are owned
by others. In 1984 the NTMWD treated 8,725, 000, 000 gallons of sewage
or approximately 23.8 million gallons per day in a cost effective
program that provided the necessary expertise to satisfy the Federal
and State Agencies at a reasonable cost to the entities served.
As the area grows, regionalization will create benefits by reducing the
number of plants in the area and assuring that adequate treatment is
performed. It has been the goal of the NTMWD to work with the
individual cities to attempt to provide regional plants within the scope
of the NTMWD Regional Cross-Pledged Revenue Bond Program.
Currently Richardson, Plano, Allen, Mesquite and McKinney are
involved in this program. A plant to serve Wylie and portions of
Sachse, Murphy, St. Paul and Rowlett, would make engineering sense
and could possibly be economically developed by cooperation in the
area through the NTMWD.
Another major feature of the NTMWD program utilizes NTMWD revenue
bonds to finance construction facilities, either through the Regional
Program or as Special Project Plants. Our three largest plants are in
the Regional Program but special project financing has financed plants
for Rockwall, Murphy and Heath.
WYLIE WASTEWATER TREATMENT
Initially the NTMWD worked with the City of Wylie in issuing NTMWD
Revenue Bonds under the State Compact Agreement which allowed the
City to receive a larger grant and low interest cost on the program for
the construction of an interceptor line, treatment plant, and other
miscellaneous wastewater improvements. Those bonds are now being
repaid based on a contractual agreement between the City and the
NTMWD in the approximate amount of $12, 000 a year until the year
1996. Without the assistance of the NTMWD it would have not been
possible for the City to have received a grant in the proportion that it
did, or receive the lower interest rate of the bonds that were issued.
Mr. Gus Pappas
City Manager
City of Wylie
July 26, 1985 - Page 3
PERMIT REQUIREMENTS
The current Wylie Wastewater Treatment Plant was designed for 20
mg/I BOD and 20 mg/I TSS and these were the requirements in the
initial permit. Later the Texas Department of Water Resources through
the Texas Water Commission developed regulations requiring any plant
that discharged within five miles of a water supply reservoir to meet
10 mg/I BOD and 15 mg/I TSS requirements. The City started to
construct additional filters at a cost in excess of $250,000; however,
the NTMWD working with the State, developed a plan to operate this
plant within the 10-15 perimeters without the expense of the additional
facilities. The NTMWD has met this goal except for the winter months
and therefore the City has avoided expending these funds based on
the expertise developed in the NTMWD staff. The plant has met the
10-15 requirement 18 out of the last 21 months and is still doing an
excellent job considering the design features of the plant. The
expertise of the NTMWD System is reflected when you review the
supervision of the system. Mr. Dolan McKnight, Wastewater Treatment
Systems Manager, has a Masters Degree in Chemical Engineering from
Rice University with over fifteen years wastewater experience, and his
assistant, Mr. David Morgan, has a degree in Biology and several
years experience in laboratory and wastewater treatment processes.
These supervisors, operating with advanced licensed operators, can
achieve greater operational efficiency of the plants than can be
achieved strictly on a local level.
OPERATORS
The NTMWD has operators classified A, B, and C, that work daily at
the various wastewater treatment plants. The necessary operations
ability are available when men are ill or on vacation to still oversee the
practical operation of the plant. The majority of small cities do not
have the depth to see that the plants are operated properly. In the
NTMWD Budget the cost of operators are scheduled each year based
upon the amount of time necessary to operate each plant. Last year
$9,608 was charged to the City of Wylie for operating personnel. I do
not believe that the City of Wylie can provide the skilled operational
personnel to operate this plant at anywhere near this cost.
MAINTENANCE SERVICE
The NTMWD provides for maintenance service through the central
maintenance operations of the NTMWD where skilled mechanics and
electricians, supervised by maintenance engineers, perform the work
based on work orders. When an operator finds a problem he radios to
the central control room for assistance and the personnel to perform
the necessary work are dispatched. Periodically on an oxidation ditch
plant the rotors have major mechanical problems. The NTMWD is
capable of removing the large equipment, replacing bearings, welding,
Mr. Gus Pappas
City Manager
City of Wylie
July 26, 1985 - Page 4
and replacing the equipment at a minimum cost. The City would of
necessity, have to employ an outside person to do this work at a much
higher cost. (This was the major reason that the City of Forney
contracted with the NTMWD when they were faced with expenditures of
$35,000 to $40,000 for a repair of their rotor which collapsed in their
ditch. The NTMWD repaired this unit at a cost of slightly over
$3,000) .
SUPPLIES AND CONTRACTUAL SERVICES
The Supplies and Contractual Services purchased by the NTMWD on a
large wholesale basis are provided at cost to the cities participating in
the program. The cost of chlorine, etc, will be greater to the City of
Wylie purchasing individually than through the NTMWD. The largest
single cost is electrical service which would be the same with either
entity providing the service and this cost is between $15,000 and
$18,000 annually.
In summary, it is hard to believe the City will be able to run the
system at a lower unit cost than currently being accomplished by the
NTMWD. Many times the cost of operating the plants are included with
other costs and become difficult to fully determine in a municipal
budget. But under any circumstance, it is difficult to imagine that the
City of Wylie can develop comparable expertise or have available the
diversified equipment and skills to operate the City's facility that can
be accomplished through the NTMWD.
However, the benefits are not limited to current situations but include
the ability of the NTMWD to work with the City and its' neighbors to
develop a regional program. This does appear to have much merit in
this particular situation. The future possibilities of developing a plant
downstream from the current site in conjunction with others would be
difficult for a city due to the competition between cities, but utilization
of the NTMWD has many times accomplished this type of a program
along with the many cost benefits to all participants. Under any
circumstance, we hate to see the City of Wylie changing its course and
determining not to utilize the NTMWD. Currently the Cities of
Richardson, Piano, Mesquite, Allen, McKinney, Rockwall, Royse City,
Forney, and Heath have chosen to work together through the NTMWD
for the benefits that will be derived.
To answer your last question, there are no outstanding debts other
than the revenue bond debt service which must be paid by the City
under a separate contractual agreement through the year 1996. At the
end of this fiscal year there may be a credit or a debit on the plant
which is currently calculated under Budget by $3,000. We hope that
you will reconsider this matter and if we may meet with you or the
City Council for any further discussions, please do not hesitate to
contact my office.
Sinc
(�iIQJw
CARL W. RIEHN
CWR :md Executive Director
CITY OP' WY'LI3M
114 N. BALLARD ST. — P.O. BOX 428
WYLIE,TEXAS 75098
(214)442-2236
July 8 , 1985
Mr . Carl Riehn, Executive Director
North Texas Municipal Water District
P. 0. Drawer C
Wylie , Texas 75098
Dear Mr. Riehn:
While in the past, the City of Wylie has not had in it ' s
employ a sufficient number of qualified state licensed
sewage operators, we feel that now we do have. Because of
this fact, we are considering terminating the contract for
sewer services between the City of Wylie and the NTMWD
effective October 1 , 1985 , the beginning of our new fiscal
year . In order to consider this matter properly and to
place the necessary funds in next year' s budget , we need to
know if there are anymore outstanding debts to be paid
separately that remain from the repairs and improvements
done several years ago. In addition, we wish to continue
the use of your testing facilities in order to comply with
state requirements ; thus, we need to know your charge for
those services .
Please review these considerations with your staff and
contact either me or Bill Windham, our Director of Public
Works with the information we have requested .
I am sure I speak for the Council as well as myself when I
convey our appreciation for your extension of this
assistance and services in the past . Please do not think of
this as anything but a maturing of capabilities of the City
of Wylie and it' s ability to handle it' s own affairs.
Gus H. app s
City Manager
GHP: bl
cc: City Council
41,1
4111W--
4110.
41110.
Immullimmor
NORTH TEXAS MUNICIPAL WATER DISTRICT
P.O.DRAWER C
WYLIE,TEXAS 75098 REGIONAL SERVICE THROUGH UNITY
PHONE NO.442-5405
September 4, 1985
Mayor John Akin
City of Wylie
P. O. Box 428
Wylie, Texas 75098
Dear Mayor Akin:
Enclosed is a report on the Wylie Wastewater Plant prepared by Dolan
McKnight, P. E. , Wastewater Systems Manager, that should satisfactorily
respond to the letter you received from the Texas Department of Water
Resources, Duncanville Office, that requires the City to submit an
engineering report by October 25, 1985. The TDWR and EPA have
requested such reports from other cities such as Richardson and Piano that
are experiencing rapid growth. The EPA is under mandate from Congress to
have all plants compliant by July 1, 1988. Further, the Texas Legislature
increased the enforcement powers of the Texas Water Commission and
dismantled the Texas Department of Water Resources mainly because they
did not think the TDWR had been strict enough on permit violations.
Therefore, such letters have become frequent. However, the TDWR letter
does emphasize the importance of Wylie's beginning immediately to formalize
planning for its' growing wastewater needs with a deadline of January 1,
1988 to get expanded facilities in service.
Note that the recommendations of the report call for a detailed engineering
study to determine your wastewater needs for the next few decades and the
optimum facilities to meet them. The NTMWD would appreciate the
opportunity to coordinate such a study for you as it has done for other
cities such as Plano, Allen, McKinney, Richardson, Rockwall, Forney, and
Mesquite and thinks that it could lend valuable experience to insure that
the facilities planned are adequate for your interim and long term needs and
are cost effective. However, since Wylie is not a member of the NTMWD's
regional system the cost of such a study would be in excess of the budget
for operations of the plant.
The report also recommends sampling of industry to determine its impact on
the plant and possible pretreatment needs. The NTMWD does have the
automatic sampling equipment and laboratory capabilities to conduct such a
study and could carry it out with a request and proper authorization by
the City.
Mayor John Akin
City of Wylie
P. O. Box 428
Wylie, Texas 75098
September 4, 1985, Page two
The NTMWD, both because of its responsibility to the State as the
designated Regional Operator in the East Fork of the Trinity River, and
more importantly, its long association with Wylie, is vitally concerned that
the City develops the best overall program. The NTMWD staff is prepared
to discuss this with you or the City Council.
If you have any questions regarding the enclosed report or wish further
discussions please do not hesitate to contact my office.
Sinn
6tAa
CARL W. RIEHN
Executive Director
CWR/DM:md
Enclosure
NORTH TEXAS MUNICIPAL WATER DISTRICT
REPORT ON THE WYLIE WASTEWATER
TREATMENT PLANT
AS REQUESTED BY THE
TEXAS DEPARTMENT OF WATER RESOURCES
DUNCANVILLE OFFICE
BY M. DOLAN MCKNIGHT, P. E.
WASTEWATER SYSTEMS MANAGER
REPORT ON THE WYLIE WASTEWATER TREATMENT PLANT
PURPOSE
The Texas Department of Water Resources (now Texas Water Commission)
Duncanville Office, in a letter dated August 19, 1985, has requested an
engineering report to address:
"1 . Design discrepancies of the Wylie Wastewater Treatment Plant with the
'Design Criteria for Sewage Systems'. . ."
2. Capability of the Wylie Wastewater Treatment Plant to consistently meet
effluent requirements as listed in Permit No. WO001384-001 ."
This report will address the compliance history of the Wylie plant, the
relationship of this history to design criteria, and the areas of concern that
should be addressed in future permits and facilities to meet the city's expected
growth.
COMPLIANCE HISTORY
The Wylie plant has had an excellent compliance history in meeting it's current 20
mg/I monthly average BOD5, (5-day biochemical oxygen demand) 20 mg/I TSS
(total suspended solids) permit for a maximum monthly flow of .8 MGD (million
gallons per day) . The plant has not had a permit violation for the last two years
(July 1983 - June 1985) and has averaged 7 mg/I BOD5 and 9 mg/I TSS during
this period.
The only months of non-compliance in the last five years were November 1980 -
February 1981 cited in the TDWR letter and June and July of 1984, both periods
involving extensive repair of the rotors that supply oxygen to the process.
Therefore, in the last sixty months, fifty-four months were compliant with BOD
and TSS - a 90% compliance record. In the six non-compliant months the average
BOD5 was 30 mg/I and TSS was 29 mg/I, which is still within EPA's definition of
secondary treatment. Therefore, the Wylie plant does not need to correct an
existing problem, but must insure continued compliance in the future as the
community grows and permit parameters become stricter.
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DESIGN STANDARDS
The TDWR letter notes two variances of the Wylie plant from present design
standards and alludes to a potential problem with a third. It should be noted that
at the time of plant construction in 1971, the plans were approved by the Texas
Department of Health and met the design standards in force at that time. Since
then, design standards of the State have become much more conservative to
provide a large safety factor so that effluent requirements can be met in cases of
high loading, minimal operator attention, etc. Plants, such as is the case in
Wylie, can be operated at conditions exceeding the design standards if there are
no adverse influent conditions, such as toxic wastes or unusual infiltration, and
operator attention is diligent.
1. Clarifier overflow rate -
As noted in the TDWR letter, the clarifier surface loading at design
flows is 786.6 gpd/ft.2. To meet new state Design Criteria of 300 gpd/ft.2 a new
47 ft. diameter clarifier would be needed.
In the past year the maximum monthly flow was .682 MGD. The average
yearly flow (July 84 - June 1985) is .531 MGD. Effluent requirements has been
met during this period. These flows result in clarifier overflow rates of 709
gpd/ft. 2 maximum monthly and 552 gpd/ft.2 yearly average. Such overflow rates
are beyond the recommended literature values for oxidation ditches (300-500
gpd/ft. 2) , but not beyond the rates for the conventional activated sludge process
(440-800 gpd/ft.2) . 1 It is apparent that the overflow rates are approaching the
limits of the clarifier's capabilities and modifications may be needed to maintain
effluent quality if flow approaches the maximum monthly value of .800 MGD.
Oxidation ditch sludges can be made more settleable by the addition of
polymer and thus higher overflow rates on the clarifier can be sustained. A
polymer addition system is relatively inexpensive ($5,000) and can be implemented
within two months if needed, while the construction of an additional clarifier
would take more than a year to accomplish at considerable expense ($250, 000) .
While polymer addition is not a permanent solution for hydraulic overloads, it can
be an excellent interim measure for permit compliance when rapid growth occurs.
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2. Drying bed capacity. -
As noted in the TDWR letter, the present drying beds are one-third
the capacity recommended in the design criteria. While oxidation ditches generate
considerably less sludge per capita than do other processes, the plant operators
have, under present loading conditions, had difficulties in removing adequate
sludge from the process during late winter - early spring weather conditions
when drying time is maximum. If sludge is not consistently removed from the
process, it will eventually be discharged in the effluent, resulting in permit
violations.
There are three remedies to inadequate drying bed capacity; (1) reduce
loading by pretreatment (see below) , (2) build more beds, or (3) install a
polymer system that decreases drying time. Drying beds are relatively
inexpensive to construct, particularly if they are to be used only on an interim
basis. Alternatively, if a polymer system is added to improve clarification, it can
also be used to enhance sludge drying.
3. Aeration Capacity. -
As noted in the design criteria, "There shall be a minimum of 2 rotors
per ditch, each having the capability of supplying the required oxygen capacity
with ( 1) rotor out of service." The Wylie Plant does have two rotors, each
capable of supplying sufficient oxygen to adequately treat normal domestic sewage
for a population of 10,000 - approximately 1700 lbs/day of BOD and TSS2.
As shown in Table 1, the average BOD loading was 2, 551 lbs/day. The
highest monthly loading was 10,048 lbs/day, based on an influent concentration of
one sample of 4,500 mg/I. Five months last year had a loading of less than 1,000
lbs/day, which would be typical of normal domestic sewage. If the Wylie Plant
treated normal domestic sewage only, one rotor would be more than adequate.
Wylie has two industrial contributors that significantly impact the BOD
loading, the Wylie Locker Plant and Oklahoma Animal By Products. Since sampling
is only done one day per week during the 8 A.M. - 5 P.M. period, and does not
reflect the low night time waste strength, the loading shown in Table 1 is
probably much higher than actual, but it illustrates the impact and variability of load-
ing these contributors introduce.
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TABLE
INFLUENT LOADING
MONTHLY AVG. BODS (mg/I) TSS (mg/I) BOD5 (Ibs/day) TSS (lbs/day)
DATE FLOW (MGD) AVG. MAX. AVG. MAX AVG AVG.
Aug. 84 .376 142 220 130 150 445 141
Sept. .445 119 128 87 130 442 323
Oct. .356 190 430 106 162 564 315
Nov. .514 2344 4500 324 710 10,048 1389
Dec. .682 1016 3400 616 2155 5,779 3504
Jan. 85 .536 884 2400 131 144 3,952 586
Feb. .612 560 800 144 220 2,858 735
Mar. .666 333 550 140 150 1,850 778
Apr. .457 379 750 370 1062 1, 445 1410
May .666 135 151 155 186 750 861
June .619 292 390 106 160 1,507 547
July .640 187 198 346 668 966 1084
AVG . .547 548 209 2, 551 973
Because of this loading, the two rotors are both run with maximum
submergence. This provides 4, 168 lbs/day of oxygen. Assuming one pound of
oxygen per pound of BOD removed, this normally provides sufficient oxygen to
meet the loadings imposed by the industrial waste, but does not provide a spare
rotor. The Wylie plant has had problems meeting effluent standards when repair
work on the rotors removed one of them from service for extended periods. The
plant has not had problems meeting effluent limits because of the industrial
contribution when both rotors are functioning.
The NTMWD does have available 7.5 H.P. floating aerators. Four of
these can be located in the ditch to handle peak load demands if a 30 H.P. rotor
must be removed from service. Alternatively, adequate pretreatment of industrial
waste or a ban on its release when an aerator is out of service would prevent
overload of the plant when an aerator is being repaired.
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PRESENT SITUATION
The City of Wylie has grown slowly through the last decade until the
last couple of years. As shown in Table 1, flow has increased substantially the
last year, averaging .547 MGD for August 1984 - July 1985 vs. . 437 MGD for the
three previous years, a 25% increase. While some of this increase is attributable
to heavy rainfall and subsequent infiltration this year, it also reflects the
increased recent growth of the city, which is expected to continue.
The City of Wylie's State Discharge Permit also expired in October 1984.
Although its conditions remain in force until a new permit is issued, it is
anticipated that the new permit will be stricter and conform with most permits for
plants that discharge into drinking water supplies; the 20 mg/I BOD5 and 20 mg/I
TSS will become 10 mg/I BOD5 and 15 mg/I TSS. It would be advisable for the
new permit to provide for a larger capacity to conform to the city's expected
growth in the next decade.
RECOMMENDATIONS
1. An engineering study should be made addressing the following questions:
a. What is Wylie's anticipated need for sewage plant capacity in the next
five, ten, and twenty years?
b. Are there other cities or unincorporated areas that could best be
served through a joint plant located downstream from the present?
c. Where should a new plant be located to best serve Wylie's and other
potential user's long term needs?
d. Should the present plant remain in service for an extended time beyond
the construction of new facilities?
e. Will the new facilities be incorporated in the present ones?
f. Should the new plant be staged to minimize front end cost impacts?
2. A Permit Application should be prepared based on the alternative in the
engineering report decided on.
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3. If the present plant is to remain in service for several years beyond the life
of a new facility or is to be Incorporated in the new facility, engineering
plans for a new clarifier, filters, and/or drying beds should be started.
This can be done before a permit for increased flow is granted.
4. If the present plant is to be abandoned as soon as new facilities are
constructed, interim measures such as polymer addition to the clarifier and
drying beds should be considered.
5. A study of the actual industrial waste contributions and measures for
pretreatment should be explored at the Wylie Locker Plant and Oklahoma
Animal By Products to lessen the loading of the treatment plant.
SUMMARY
The TDWR has noted by letter that the Wylie Wastewater Plant does not meet
State Design Criteria for wastewater plants at its' design and present flow and
loadings. The plant, however, has been able to meet its' effluent requirements
some 90% of the time in the last five years. Expected growth in Wylie could result
in more frequent violations of its' effluent parameters in the near future.
An engineering study is needed to address what facilities are needed to treat
Wylie's wastewater in the next two decades in a cost effective manner. The
outcome of that study will determine what permit should be applied for, what
interim measures should be employed at the present plant to preclude violations
and the time frame for construction of facilities to meet Wylie's expanding needs.
REFERENCES:
1 . Oxidation Ditches in Wastewater Treatment, Mikkel G. Mardt S Bruce A. Bell,
Ann Arbor Science, 1982. p. 145.
2. Operation and Maintenance Manual; City of Wylie, Texas, Water Pollution
Control Plant, Henningson, Durham 6 Richardson, 1973, p. 2.
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