79-02 O - User Charge for Capital Cost Recovery No. ?
AN ORDINANCE
TO ESTABLISH A USER CHARGE SYSTEM FOR CAPITAL COST RECOVERY AND FOR SERVICES
RENDERED FOR OPERATION AND MAINTENANCE OF THE WASTE WATER TREATMENT WORKS BY
THE CITY OF PROSPER, TEXAS.
WHEREAS, the City of Prosper, Texas has provided a system of charges to assure
that each recipient of waste treatment services will pay its proportionate
share of the capital cost recovery and operation and maintenance, including
replacement, of the waste water treatment works.
NOW, THEREFORE BE IT ORDAINED BY THE CITY COUNCIL OF THE CITY OF PROSPER,
TEXAS:
SECTION 1. DEFINITIONS . As used in this ordinance
(1) "B.O.D." (Biochemical Oxygen Demand) means the quantity of oxygen
by weight; expressed in mg/l, utilized in the biochemical oxida-
tion of organic matter under standard laboratory conditions for
five (5) days at a temperature of twenty (20) degrees centigrade.
(2) "CAPITAL COST RECOVERY" means amortization and interest charges for
the bonded indebtedness of the City.
(3) "CITY" means the City of Prosper , Texas, or any authorized
person acting in its behalf;
(4) "MILLIGRAMS PER LITER" (mg/1) means the same as parts per million
and is a weight-to-volume ratio; the milligram-per-liter value
multiplied by the factor 8.34 shall be equivalent to pounds per
million gallons of water;
(5) "NORMAL DOMESTIC WASTEWATER" means wastewater excluding industrial
wastewater discharged by a person into sanitary sewers and in which
the average concentration of total suspended solids is not more
than 250 mg/1 and BOD is not more than 250 mg/1;
(6) "REPLACEMENT" means expenditures for obtaining and installing
equipment, accessories, or appurtenances which are necessary dur-
ing the useful life of the treatment works to maintain the capacity
and performance for which such works were designed and constructed.
The term "operation and maintenance" includes replacement;
(7) "SUSPENDED SOLIDS" means solids measured in mg/1 that either float
on the surface of, or are in suspension in, water, wastewater, or
other liquids, and which are largely removable by a laboratory fil-
tration device;
(8) "TREATMENT WORKS" means any devices and systems for the storage,
treatment, recycling, and reclamation of municipal sewage, domestic
sewage, or liquid industrial wastes used to implement Section 201 of
of the Clean Water Act, or necessary to recycle or reuse water at
the most economical cost over the useful life of the works;
(9) "USEFUL LIFE" means estimated period during which a treatment works
will be operated;
(10) "USER CHARGE" means a charge levied on users of a treatment works
or that portion of the ad valorem taxes paid by a user, for the
user's proportionate share of the cost of operation and maintenance
(including replacement) and capital cost recovery of such works;
(11) "WASTE" means rejected, unutilized or superfluous substances in
liquid, gaseous, or solid form resulting from domestic, agricultur-
al, or industrial activities ;
(12) "WASTE WATER"means a combination of the watercarried waste from
residences, business buildings, institutions, and industrial estab-
lishments, together with any ground, surface, and storm water that
may be present.
SECTION 2. CLASSES OF USERS.
Two classes of users shall be established based on similar flows
and waste water characteristics, i.e. , levels of biochemical oxygen
demand, suspended solids as follows:
(a) Domestic user class (250 mg/1 or less of BOD and Suspended Solids);
(b) Industrial user class (251 mg/1 or more of BOD and Suspended Solids);
• and
(c) other parameters the State may require as they become necessary.
1.
SECTION 3. CRITERIA FOR USER CHARGES.
(a) User charges for capital recovery and operation and maintenance
costs are to be distributed to each user or user class within the
City's jurisdiction in proportion to such user's contribution to the
total waste water loading of the treatment works based on the follow-
ing factors:
�r (1) strength (BOD and Suspended Solids) ;
(2) volume (total contribution of pollutants per day) ; and
(3) delivery flow rate characteristics (gallons per minute) .
(b) First year operation and maintenance costs are to be based upon
past experience for existing treatment works and estimated cost re-
quirements of the new treatment works.
(c) Annual review of waste water contribution of users and user clas-
ses, the total cost of operation and maintenance of the treatment
works and its approved user charge system. The City shall revise
the charges for users or user classes to accomplish the following:
(1) Maintain the proportionate distribution of operation and mainten-
ance costs among users and user classes as required herein;
(2) Generate sufficient revenue to pay the total operation and main-
tenance costs necessary to the proper operation and maintenance
(including replacement) of the treatment works; and
(3) Apply excess revenues collected from a class of users to the
costs of operation and maintenance attributable to that class
for the next year and adjust the rate accordingly.
(d) Any user which discharges any toxic pollutants which cause an in-
crease in the cost of managing the effluent or the sludge of the
City's treatment works shall pay for such increased costs.
(e) Charges for operation and maintenance for extraneous flows not
directly attributable to users (i.e. , infiltration/inflow) shall be
distributed among all users of the City's treatment works system
based upon flow volume of the user and user class and is included in
the operation and maintenance cost charge.
(f) Each user shall be notified annually, in conjunction with a regu-
lar bill, of the rate and that portion of the user charges or ad val-
orem taxes which are attributable to waste water treatment services.
(g) Construction of sewer connections shall be in accordance with the
"Uniform Plumbing Code" as promulgated by the International Associa-
tion of Plumbing and Mechanical Officials.
(h) Inspection of sewer connection construction shall be approved by
city inspectors prior to use.
SECTION 4. USER CHARGE SCHEDULE.
(a) Capital Recovery Cost protion of the user charges will be distri-
buted to the users on an equal basis and constitute a minimum charge
of $4.00 per month for the first year of operation based on 230 ex-
pected sewer connections and computed as follows:
• $130,000 indebtedness at 51/2I per annum for 20 years
Annual Amount = 130,000 x 0.08368 (CRF) = $10,878.40
Cost per Month = 10,878.40 = $906.53
12
Cost per User per Month = $906.53 = $3.94 or $4.00
12
(b) Normal Domestic Waste Water Use based on volume in proportion to
each user's contribution to the total waste water loading of the
treatment works is 0.87 per thousand gals. Residential users shall be
charged only on the water use of up to 8000 gals. per month with all
other users charged for total use and computed as follows:
Cu t t u
(1) Symbols used in the formula are defined as follows:
Ct = Total operation and maintenance (0 & M) costs per unit M of
time.
Cu = A user's charge for 0 & M per unit of time.
Vt = Total volume contribution from all users per unit of time.
Vu = Volume contribution from a user per unit of time.
(2) Calculations for first year 0 & M as follows:
1000.00 0 & M Cost per Month = $0.000869/gal.
5000 gal. avg.wtr.use/month x 230 connections
= $0.87/1000 gals.
(3) No charge to users for potable water used and not returned to
the sewer system for treatment. City requires documentation cer-
tifying water use.
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(c) Total basic user charges are as follows:
(1) Sewer Connection Charge per connection = $75.00
(2) Capital Cost Recovery per User = $4.00 per month.
(3) Operation and Maintenance cost per User = $0.87/1000 gals/mo.
(on first 8,000 gals._ per mo. for residential users only.)
(d) A Surcharge will be levied when BOD, Suspended Solids or
other pollutant concentrations from a user exceed the range of con-
centration of these pollutants in normal domestic sewage. This sur-
charge will be in addition to the basic user charges of Capital Cost
Recovery and Operation and Maintenance (including Replacement.) The
following formula is to be used in computing the surcharge:
Cs = [Bc(B) + Sc(S)] Vu
(1) Symbols used in the formula are defined as follows:
Cs = A surcharge for waste waters of excessive strength.
• B = Concentration of BOD from a user above or base level of
250 mg/1.
Be = 0. & M. cost for treatment of a unit of biochemical oxy-
gen demand (BOD) .
S = Concentration of Suspended Solids from a user above a
base level.
Sc = 0. & M. cost for treatment of a unit of Suspended Solids.
• Vu = Volume contribution from a user per unit of time.
(2) Criteria for surcharge is based on following:
(A) Volume cost per user is automatically accounted for in
the surcharge equation by Vu; therefore, the total 0. & M.
surcharge cost will be considered to be due either to BOD
or Suspended Solids.
(B) Assuming that BOD accounts for 55% and SS accounts for
45% of the total annual 0. & M. expense of $12,000.00
then costs attributable to each are to be calculated as
follows:
BOD Cost: 5570 of $12,000.00 = $6,600.00 per year
= $550.00 per month.
SS Cost: 45% of $12,000.00 = $5,400.00 per year
= $450.00 per month.
Total Sewage Flow: 5,000 x 23 = 1,150,000 gallons per month
or 38,400 gals. per day average flow.
(3) Unit Costs for Surcharge Rate:
Be = $550/250 x 1.15 = $1.92 per mg/1 per million gals per mq and
Sc = $450/250 x 1.15 = $1.57 per mg/1 per million gals per mo..
4:: SECTION 5. EFFECTIVE DATE.
This ordinance shall be in full force and effect from and after its
passage, approval, recording, and publication as provided by law.
PASSED AND APPROVED ON THE Day of ,197 .
�,9y
City of Prosper , Texas
By 70/
MayoATTEST:
(/5 ikz,-,c,-Al
City Secretary
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