HomeMy WebLinkAboutA002 - Council Action Form dated April 25, 1989 ITEM #
DATE April 25, 1989
COUNCIL ACTION FORM
SUBJECT: Surcharge for High-Strength Wastewater Discharge
BACKGROUND:
Section 204(b) of the Clean Water Act and 40 CFR 35.2140 require the City
to adopt a sewer use ordinance which, among other items, includes a
surcharge to recover the actual cost of treating wastewater that is higher
in strength than normal domestic sewage. The City included such a
surcharge in the sewer use ordinance adopted on May 28, 1985.
Implementation of the surcharge was postponed until the new treatment
plant began operation. Partial startup of the new plant is anticipated
within the next month. Staff has developed a procedure to implement the
high-strength sewer use surcharge to begin billing and collecting the
surcharge on a monthly basis on October 1, 1989. A preliminary copy of
this procedure was distributed on April 4 to all of the industrial users
that may be affected by the surcharge. A meeting was held on April 19 to
answer questions and obtain input from these industries. Representatives
from four of the industries attended; no revisions or modifications have
been suggested.
A copy of the proposed procedure is attached. Ordinance changes have
also been prepared by the City Attorney for Council consideration on April
25, 1989.
ALTERNATIVES:
1. Approve the proposed procedure for implementation of high-strength
sewer use surcharge. Authorize staff to implement this federal
requirement.
2. Do not approve the proposed procedure.
MANAGER'S RECOMMENDED ACTION:
It is the recommendation of the City Manager that the City Council approve
the proposed procedure for implementation of high-strength sewer use
surcharge as outlined in Alternative No. 1.
COUNCIL ACTION:
4/89
PROCEDURE FOR EWPLEMENTATION OF
HIGH-STRENGTH SEWER USE SURCHARGE
AMES, IOWA
PURPOSE
To establish an equitable method of assessing the surcharge to be
billed to contributors identified in the Ames Non-Domestic Waste
Pretreatment Program who discharge wastewater that is higher in
Biochemical Oxygen Demand (BOD) , Suspended Solids (SS) , or Ammonia
(NH3) than normal domestic wastewater.
BACKGROUND
In order to receive approximately $20 million in federal grant funds
for the new water pollution control project, the City is required to comply
with numerous federal regulations. Section 204(b) of the Clean Water Act
and 40 CFR 35.2140 require the City to adopt a sewer use ordinance
which, among other items, includes a surcharge to recover the actual cost
of treating wastewater that is higher in strength than normal domestic
sewage. Attachment No. 1 is a copy of 40 CFR 35.2140. The strength of
the wastewater is determined by the concentrations of biochemical oxygen
demand, suspended solids, and ammonia.
The City included such a surcharge system in the sewer use
ordinance adopted on May 28, 1985. The city's sewer use ordinance has
been approved by state and federal regulatory agencies as meeting the
minimum requirements of the federal law. The new water pollution control
plant will begin operation during the early summer of 1989. With the
initial operation of the new facilities, the City must begin collecting the
extra-strength sewer use surcharge adopted for the facility. The City will
begin billing and collecting the surcharge on a monthly basis beginning
October 1, 1989.
Normal domestic wastewater is defined in the City Code, Section
28.37, as any wastewater that has a biochemical oxygen demand (BOD)
concentration of not more than 250 milligrams per liter (mg/1) average and
400 mg/1 maximum; or a suspended solids (SS) concentration of not more
than 300 mg/1 average and 450 mg/1 maximum; or an ammonia (NH or
NH3-N) concentration of not more than 40 mg/1 average and 60 mg/1
maximum. Pages from two standard industry reference books illustrating
sewage wastewater strengths are shown as Attachment Nos. 2 and 3.
Section 28.39, paragraph 4, of the Code further states "For those users
whose wastewater has a greater strength than normal domestic sewage, a
surcharge in addition to the normal user charge will be collected. The
surcharge for operation and maintenance, including replacement, is: $0.08
per pound BOD; $0.14 per pound SS; $0.20 per pound NH3." The
surcharge amounts are based on estimates of operation, maintenance, and
replacement costs at the new plant. After the plant has been in operation
for several years, these costs will be re-evaluated and may change to
better reflect actual costs. A survey of surcharge rates from several Iowa
cities is shown as Attachment No. 4.
IMPLEMENTATION
Those customers identified through the Ames Non-Domestic Waste
Pretreatment Program who contribute wastewater stronger than domestic
sewage for any of the identified parameters (i.e. BOD, SS, NH ) shall pay
a monthly sewer surcharge based on that customer's respective discharge
strength and monthly volume. This surcharge shall be in addition to the
normal sewer use charge which is based only on volume.
In order to establish an initial data base on which to base the
surcharge, a sampling set per discharge point will be collected from all
contributors associated with the pretreatment program. A sampling set is
defined as three consecutive 24-hour composite samples collected during a
normal work week. The City will contract with a commercial laboratory to
obtain and analyze the samples. This sampling will be done at the city's
expense. Based on the data, a surcharge will be calculated for the
contributors who have wastewater higher in strength than normal domestic
sewage. Once the contributor is notified of the surcharge, he has the
option of modifying operations to reduce strength and resampling at his
expense or pay the monthly surcharge which will begin October 1, 1989.
The monthly city utility bill will include a line for identification of
the sewer surcharge amount. The sewer surcharge rate will be calculated
for each contributor at least once annually and may be calculated on a
more frequent basis if additional sampling data is provided.
The City will require one sampling set per discharge point, as
defined above, for each contributor subject to the surcharge at least once
per year to calculate the surcharge rate for the following year. Following
the establishment of the initial data base, all costs for the sample collection
and analysis associated with the surcharge requirement is the
responsibility of the contributor. The sample results must be
representative of the normal wastewater discharge from that contributor.
Samples collected during weekends or shutdown periods will not be
accepted. The sampling results shall be reported to the City Water and
Pollution Control Department at least 45 days prior to the beginning of the
billing year (July 1). If the customer desires, additional sample results
may be submitted at any time during the year and used to revise the
surcharge calculation. The surcharge billing will be adjusted at the first
billing cycle following the recalculation. The approximate cost of three
days of sampling and analyses for these parameters is estimated to be from
$350 to $500 (per discharge point) . City staff can provide a list of
several commercial laboratory facilities which are able to perform this
work.
The extra-strength surcharge has been established as follows:
Surcharge Rate Per
Parameter Extra-Strength Rate mg/1 of Extra Strength
BOD $0.08/lb $0.00050/100 cf
SS $0.14/lb $0.00088/100 cf
NH3 $0.20/lb $0.00125/100 cf
-2-
The surcharge rate applies only to the extra strength above normal
domestic waste strength. The total surcharge rate is the sum of the rates
for each individual parameter. This surcharge rate will be used for the
entire 12-month billing year (fiscal year) or until the next sample set is
submitted. If any parameter is below average domestic strength, there
will not be a surcharge for that parameter. A sample calculation for a
typical monthly surcharge is shown as Attachment No. 5.
If the City develops data which indicates the surcharge rate may be
incorrect, the City may request the contributor to submit an additional
sample set to verify the current surcharge rate. The sample sets used for
the surcharge calculation can also be used by the contributor to meet the
self-monitoring requirements of the industrial pretreatment program.
Sampling duplications will not be required where a sample can be used for
more than one purpose.
The City will work with each contributor to minimize monitoring
expenses. The existing data base will be reviewed with each contributor
to determine if it is adequate for calculation of the surcharge rate.
Additional sampling sets may not be needed as long as the data base
remains valid. However, either the City or the contributor can request
additional sampling sets if either feels the data base is not representative
of current wastewater discharge quality. If any contributor modifies its
operations, such as through a plant expansion or elimination of a product
line, then either the City or the contributor can request a new sampling
set to determine a new or modified data base.
If any contributor demonstrates that its discharge does not exceed
the strength of domestic wastewater, there will be no surcharge. Future
sampling requirements may be reduced or eliminated until conditions
warrant.
-3-
ATTACHMENT 1
Federal Register / Vol. 49, No. 34 / Friday,.February 17, 1984 / Rules and Regulations 6245
determined on the-date of the approval wastewater produced by a facility that treatment works within the grantee's
of the Step 3 grant.Grant assistance is owned and operated by the Federal service area and the grantee has
awarded after September 30,1990 shall government which contributes more continued to use that system;
be limited to the needs existing on than 250,000 gallons per day or five (2)The ad valorem user charge system
September 30,1990. percent of the design flow of the distributes the operation and
(d)For any application with capacity complete waste treatment system, maintenance(including replacement)
in excess of that provided by this whichever is less.. costs for all treatment works in the
section: (Approved by-the Office of Management and grantee's jurisdiction to the residential .
(1)All incremental costs shall be paid Budget under control number 2040--0027) and small non-residential user class
by the applicant.Incremental costs (including at the grantee's option
include all oosts which would not have §35.2130 Sewer use ordinance. nonresidential,commercial and
been incurred but for the additional The sewer use ordinance(see also industrial users that introduce no more
excess capacity,i.e., any cost in §§35.2122 and 35.2208)or other legally than the equivalent of 25,000 gallons per
addition to the most cost-effective binding document shall prohibit any day of domestic sanitary wastes to the
alternative with eligible reserve new connections from inflow sources treatment works),in proportion to the
capacity described under paragraphs(a) into the treatment works and require use of the treatment works by this class;
and(b) of this section. that new sewers and connections to the and
(2)It must be determined that the treatment works are properly.designed (3)Each member of the industrial user
actual treatment works to be built meets and constructed.The ordinance or other and commercial user class which
the requirements of the National legally binding document shall also discharges more than 25,000 gallons per
Environmental Policy Act and all require that all wastewater introduced day of sanitary waste pays its share of
applicable laws and regulations. into the treatment works not contain the costs of operation and maintenance
(3)The Regional Administrator shall toxics or other pollutants in amounts or (including replacement)of the treatment
approve the plans,specifications and concentrations that endanger public works based upon charges for actual
estimates for the actual treatment safety and physical integrity of the use.
works. treatment works;cause violation of (c)Notification.Each user charge
(4)The grantee shall assure the effluent or water quality limitations;or system must provide that each user be
Regional Administrator satisfactorily preclude the selection of the most cost- notified,at least annually,in
that it has assessed the costs and effective alternative for wastewater conjunction with a regular bill(or other
financial impacts of the actual treatment treatment and sludge dispoisal. means acceptable to the Regional
works and has thexapability to finance (Approved by the Office of Management and Administrator),of the rate and that
and manage their construction and Budget under control number 2040-0027) portion of the user charges or ad
operation. valorem taxes which are attributable to
(5)The grantee must implement a user §35.2140 User charge system wastewater treatment services. .
charge system which applies to the The user charge system(see (d)Financial management system.
entire service area of the grantee. §§35.2122 and 35.2208)must be designed Each user charge system must include
(0)The grantee shall execute to produce adequate revenues required
appropriate grant conditions or releases for operation and maintenance an adequate financial management
protecting the Federal Government from (including replacement).It shall provide system that will accurately account for
that each user which discharges revenues generated ra the system and
any claim for any of the costs of expenditures for operation and
construction due to the additional pollutants that cause an increase in the maintenance(including replacement)of
capacity. cost of managing the effluent or sludge the treatment system,based replacement)
an
from the treatment works shall pay for adequate budget identifying the basis
¢35.2125 Treatment of wastewater from such increased coat.The'user'charge for determining the annual operation
Industrial users. system shall be based on either actual >nmg P
'(a)Grant assistance shall not be use under paragraph(a)of this section, and maintenance costs and the costs of
provided for a project unless the,project ad valorem taxes under paragraph(b)of Personnel,material,energy and
is included in a complete waste this section,or a combination of the two. administration.
treatment system and the principal (a) User charge system based on (e)Charges for operation and
purpose of both the project and the actual use.A grantee's user charge maintenance for extraneous flows.The
system is for the treatment of domestic system based on actual use(or user charge system shall provide that
wastewater of the entire community, estimated use) of wastewater treatment the costs of operation and maintenance
area,region or district concerned. services shall provide tjlat each user(or for all flow not directl attributable to
.(b)Allowable project costs do not user class)pays its proportionate share users(i.e.,infiltration/inflow)be
include: of operation and maintenance(including distributed among all users based upon
(1)Costs of interceptor or collector replacement)costs of treatment works either of the following:
sewers constructed exclusively,or within the grantee's service area,based (1)In the same manner that it
almost exclusively, to'serve industrial on the user's proportionate contribution distributes the costs for their actual use,
users;or to the total wastewater loading from all or
(2)Costs for control or removal of users(or user classes). (2)Under a system which uses one or
pollutants in wastewater introduced into (b) User charge system based on ad any combination of the following factors
the treatment works by industrial users, valorem taxes.A grantee's user charge on a reasonable basis:
unless the applicant is required to system which is based on ad valorem (i)Flow volume of the users;
remove such pollutants introduced from taxes may be approved if: (ii)Land area of the users;
nonindustrial users. (1)On December 27,1977,the grantee (iii)Number of hookups or discharges
had in existence a system of dedicated of the users;
§.35.2127 Federal facilities. ad valorem taxes which collected ()v)Property valuation of the users, if
Grant assistance shall not be provided revenues to pay the cost of operation the grantee has an approved user charge
for costs to transport or treat and maintenance of wastewater system based on ad valorem taxes.
ATTACHMENT 2
PROCESS DESIGN CONSIDERATIONS
TABLE 1-III. Analysis of Typical
Midwest Domestic Wastewater
Constituent Concentrat ion,
mg/1
Total solids (TS) 980
Volatile Ts 260
Nonvolatile TS 720
Total us )ended solids (TSS) 200
Volatile Tss 160
Nonvolatile Tss 40
Chemical oxygen demand (COD) 400
Suspended COD 250
Soluble COD 150
Biodegradable COD 300
Soluble biodegradable COD 150
Suspended biodegradable COD 150
Biochemical oxyzen demand (BODO
Soluble BOD 100
Suspended BOD 100
Calcium (Ca++) 60
Magnesium (Mg++) 24
Sodium (Na+) 80
Potassium (K+) 8
Phosphate (PO4-) 30
Sulfate (SO4-) 80
Silicate (SiOM 26
Chloride (Cl-) 100
Bicarbonate (HCO3) 280
Ammonia nitrogen NH -N 30
Organic nitrogen (org-N) 20
Source: Wastewater Treatment Plant Design, WPCF/ASCE, 1977, P. 11
ATTACHMENT 3
TABLE 7.3 TYPICAL COMPOSITION OF DOMESTIC SEWAGE
(All values except settleable solids are expressed in mg/liter)
Concentration
Constituent Strong Medium Weak
Solids, total 1,200 700 350
Dissolved, total 850 500 250
Fixed 525 300 145
Volatile 325 200 105
Suspended, total 350 200 100
Fixed 75 50 30
Volatile 275 150 70
Settleable solids, (ml/liter) 20 10 5
Biochemical oxygen demand, 5-day, 200C (BOD5-200) 300 200 100
Total organic carbon (TOC) 300 200 100
Chemical oxygen demand (COD) 1,000 500 250
Nitrogen, (total as N) 85 40 20
Organic 35 15 8
Free ammonia 50 25 12
Nitrites 0 0 0
Nitrates 0 0 0
Phosphorus (total as P) 20 10 6
Organic 5 3 2
Inorganic 15 7 4
Chlorides* 100 50 30
Alkalinity (as CaCO3)* 200 100 50
Grease 150 100 50
* Values should be increased by amount in carriage water.
Source: Wastewater Engineering, Metcalf & Eddy, Inc. , 1972, P. 231
ATTACHMENT 4
Surcharges for High-Strength Wastes
(all in $/lb unless otherwide noted)
BOD TSS NH3 or TKN
Ames $0.08 $0.14 $0.20
Bettendorf 0.078 0.079 --
Burlington 0.306 0.256 --
Cedar Rapids 0.049 0.049 0.265
Clinton 0.098 0.066 --
Council Bluffs 0.024/0.05 0.034/0.07 --
< 25,000 gal/mo
> 25,000 gal/mo
Davenport 0.079 0.078 --
Des Moines 0.07/1000 gal 0.07/1000 gal --
Muscatine 0.112 0.092 --
Spencer 0.464/1000 gal 0.094/1000 gal --
\TBL\WG22.089
ATTACHMENT 5
SAMPLE CALCULATION
ABC Industry
Sample Set Results
BOD SS NH
m l mg/1 m l
Monday - - -
Tuesday 750 450 65
Wednesday 875 575 50
Thursday 300 450 55
Friday - - -
Saturday - - -
Sunday - - -
AVERAGE DISCHARGE STRENGTH 642 492 57
Normal Domestic Sewage 250 300 40
Extra Strength (Difference) 392 192 17
Calculation of Surcharge Rate
Extra Strength
Parameter mg/l Surcharge Rate Surcharge Rate
BOD: 392 x ($.000500/100 cf) = $0.1960/100 cf
SS: 192 x ($.000876/100 cf) = $0.1682/100 cf
NH3: 17 x ($.001251/100 cf) _ $0.0213/100 cf
TOTAL SURCHARGE RATE $0.3855/100 cf
Calculation of Surcharge
14,200 cf x $0.3855/100 cf = $54.74
\FORMS\TN2.089
HillO��I
AMM 50010
I it SEND PAYMENT TO
CITY OF AMES
UTILITY CUSTOMER SERVICES
P.O. BOX 811 CITY OF AMES
AMES, IA. 50010 PAYMENT MUST BE RECEIVED IN FINANCE DEPT
DEPOT ANNEX BEFORE 3PM OF DUE DATE
SAMPLE AMOUNT DUE NOW FOR OFFICIAL USE ONLY
1,035.94
ADDRESS CORRECTION REQUESTED
ABC Industry AMOUNT DUE AFTER
100 North Street 8/22/89
Ames, IA 50010 1,050.95
AMOUNT DUE INCLUDES PREVIOUS
BALANCE OF
ACCOUNT NUMBER
6/22/89 7/22/89 30 8/1/89 8/22/89 XX_XXX_X COMPARED TO SIMILAR
BILLING PERIOD LAST YEAR
.. zEmm2==lm=
99935 11398 11,463 370 GP 625.61
.003000 CR FA 34.39 CR
TOTAL ELECTRIC 591.22
225400 239600 14,200 473 Water 112.11
225400 239600 14,200 473 Sewer 242.70
225400 239600 14,200 473 Sewer Surcharge 54.74
TAX 35.17
CURRENT CHARGES 1,035.94
PREVIOUS BALANCE 0.00
ACCOUNT BALANCE 1,035.94
AMOUNT DUE NOW 1,035.94
PAYMENT MUST BE RECEIVED IN FINANCE DEPARTMENT BEFORE 3PM OF DUE DATE
SEE REVERSE SIDE FOR CODE EXPLANATION RECENT PAYMENTS MAY NOT BE REFLECTED ON THIS RILL