INDEPENDENT ENVIRONMENTAL ENGINEERS, SCIENTISTS AND CONSULTANTS 25 th Annual Region VI Pretreatment Association Workshop August 5, 2009 Wastewater Rate

INDEPENDENT ENVIRONMENTAL ENGINEERS, SCIENTISTS AND CONSULTANTS

25th Annual Region VI Pretreatment Association Workshop

August 5, 2009

Wastewater Rate Equity – Cost of Service, Customer Classes &

Surcharges


Presentation Outline1. Dallas Water Utilities (Morgan)

1. Utility Summary

2. Rate Charges

2. Utility Rate Basics (Jennifer)1. Revenue Requirements

2. Wastewater Rate Cost of Service

3. Wastewater Rate Structure

4. Customer Classes

5. Significant Industrial User Surcharges

6. Retail Customer Classes

3. Customer Class Study (Morgan Set-up, then Randy)1. Benchmarking

2. Information Collection

3. Sampling Statistics

4. Sampling

5. Grouping & Results


Dallas Water Utilities is a large, Municipally owned regional water/wastewater supplier

Self-supporting Costs are driven by infrastructure

requirements for both growth and renewal Responsibility for planning for water

requirements for service area


The department is funded from water and wastewater revenues, and receives no tax dollars

Approximately 1,500 employees Population served (treated water)

1.3 million - City of Dallas 960,000+ wholesale customer cities

699 square mile service area 306,000 retail customer accounts 4,850 miles of water mains 4,200 miles of wastewater mains 3 water treatment plants 2 wastewater treatment plants Wholesale customers

24 treated water, 3 untreated water, 11 wastewater

City of Dallas Water Utilities Fact Sheet


Morgan, Do you have a better map of the Dallas Wastewater system / service area?


Dallas Water Utilities - Wastewater

2 Wastewater treatment plants: Central and Southside

Wastewater treatment capacity: 260 MGD Wastewater pump stations: 14 Miles of wastewater main: 4,146 Wastewater treated 72 billion gallons Service Area 699 Square Miles Customer Accounts 300,000


General Fund - $1.09 billion

Enterprise Fund - $686.2 million

Debt Service - $246.2 million

Operating Budget

(day to day operation and maintenance)

$2.02 billion

General Purpose - $347.0 million


Capital Budget

(long-term capital improvements)

$ 673.0 million

FY 2008-09 Annual Budget

$2.7 billion

City of DallasFY 2008-09 Budget


Water Utilities - $511.2 million

Operating Budget

(day to day operation and maintenance)

$2.02 billion


Water Utilities - $320.0 million

Capital Budget

(long-term capital improvements)

$ 673.0 million

FY 2008-09 Annual Budget

$2.7 billion

FY 2008-09 BudgetEnterprise Fund


Convention Services - $6.0 million

Aviation - $42.5 million

Development Service - $26.8 million

Convention Services - $67.2 million

Storm Water - $35.1 million

Municipal Radio - $3.5 million


Index Cities Comparison of Average Monthly Water & Sewer Residential Bills

Note: Bill comparison based on rates effective August 2008; water consumption of 8,300 gallons; and, 6,200 gallon Winter Months Average for sewer

$36.40

$39.15

$44.10

$44.93

$48.45

$49.14

$49.83

$51.41

$51.85

$52.58

$54.32

$55.36

$60.36

$67.61

$82.03

$- $10 $20 $30 $40 $50 $60 $70 $80 $90

El Paso

Phoenix

San Antonio

Arlington

Dallas Current

Plano

Houston

Dallas Proposed

Garland

Detroit

Fort Worth

Baltimore

Philadelphia*

Austin

San Diego


Components of Water Utilities Revenues

Other Fees & Charges $ 4.0MIncludes full cost recovery for miscellaneous fees and charges such as permits and cross connection fees

Interest Income $ 10.2MInterest earned on cash in various department funds

Wholesale Sales $ 78.9MRevenue earned from sales to wholesale customers for treated water, untreated water and wastewater services

Retail Sales $418.1MRevenue from sales to retail customers for water and wastewater services including residential, commercial, industrial and municipal. Over $6.5 M is revenue from class account surcharge.

Total Revenues $511.2M


Surcharge Program

A Surcharge program is a procedure for recovering costs incurred while treating high strength waste discharged by industrial (SIU Surcharge Program) and commercial users (Customer Classes) into the wastewater system.

It is an additional charge made to a customer that discharges high strength wastewater that is amenable to treatment by the wastewater system but that exceeds the strength of normal wastewater.


DWU Customer Class Groups

Non-industrial (SIU) customers that routinely discharge Biochemical Oxygen Demand (BOD) and Total Suspended Solids (TSS) concentrations exceeding 250 mg/L are classified into the four class groups established under Dallas City Code Eating Places Equipment Service Facilities Food and Kindred Products Processing Drinking Places



1. Utility Summary

2. Rate Charges




4. Customer Classes






4. Sampling



Principal Objectives of Rate Design & Cost-of-Service Study

Develop a comprehensive cost-of-service study that properly allocates costs to each customer class to ensure a fair and equitable rate structure.

Design Rate Structure that meets community values.


Cornerstones of a Defensible User Charge System


The Three Forms of Equity


RATE SETTING PROCESS

REVENUE REQUIREMENTS

COST ALLOCATION

ASSIGN EXPENSES TOFUNCTIONAL CATEGORIES

CLASSIFY FUNCTIONALIZEDEXPENSES INTO COSTCOMPONENTS

ALLOCATE TO CUSTOMER CLASSES

RATE DESIGN



Cost-of-Service GoalRevenue Requirements

(O&M + Debt Service + Capital + Reserves)

ResidentialResidentialCost of ServiceCost of Service

Non-ResidentialNon-ResidentialCost of ServiceCost of Service


Steps in a Cost-of-Service Study


Wastewater Cost Allocation in the Broader Perspective


Issue 1: Wastewater Cost Allocation Options

Design Basis Functional Basis Hybrid Approach


Design Basis

Allocates costs based on engineering design criteria Less administrative burden Least implementation risk Potential positive impact on conservation due to

increased unit cost for wastewater treatment and disposal


Functional Basis

Allocates costs based on operational or functional purposes

Minimal administrative burden


Hybrid Approach

Allocates O&M costs based on function and capital costs based on design

More acceptable to public and political officials Increased administrative burden Improved interclass and intraclass equity Improved sustainability Recommended by consulting team


Issue 2: Customer Service Characteristics

Flow, BOD, and TSS only Considerations

Add Total Kjeldahl Nitrogen (TKN)? Add Phosphorus? Add O&G?


Flow, BOD, and TSS Only

DWU’s current methodology Least administrative burden Most common approach


Add Total Kjeldahl Nitrogen (TKN)

Difficult to implement without additional data Likely to become increasingly important in future (policy

durability – discharge permits) Improved interclass and intraclass equity Improved sustainability Recommended (once sufficient data is available from

sampling program)


Add Phosphorus

Difficult to implement without additional data Likely to become increasingly important in future (policy

durability) Improved interclass and intraclass equity Improved sustainability Recommended (once sufficient data is available from

sampling program)


Issue 3: I/I Estimation and Allocation Combined connections and volume

Minimal administrative burden Less affordable for residential customers Potential increased economic development

Contributed wastewater volume Easy to implement Easy to understand More affordable for residential customers Potential negative impact on economic development

Number of connections Easy to implement Easy to understand Less affordable for residential customers Potential increase in economic development

Land area Greatest administrative burden Greatest risk of implementation Least common approach



1. Utility Summary

2. Rate Charges




4. Customer Classes






4. Sampling



Dallas Water Utilities Customer Classes

Currently four major customer classes for establishments producing wastewater exceeding 250 BOD and 250 TSS

Eating Places Equipment Service Facilities Food and Kindred Products Processing Drinking Places


Surcharge Class Study Phase I

1. Benchmark Other Utilities

2. Develop Database Structure & Populate with Existing Data

3. Screen Database to Develop Study Groups

4. Develop Statistical Sampling Approach based on Study Groups

5. Develop Sampling & Analysis Plan


Task 1 - Benchmarking Initial benchmark study done on the following cities

City of Amarillo City of Austin City of Corpus Christi El Paso Water Utilities City of Fort Worth

Benchmark Information Number and types of customer classes Surcharge rates for BOD and TSS Average Domestic Wastewater Strengths for BOD & TSS Strength ranges for BOD & TSS

Additional Cities City of Bakersfield, CA East Bay Municipal Utility District, CA City of Fort Collins, CO City of Prescott, AZ

City of HoustonCity of LaredoCity of LubbockSan Antonio Water System


Benchmark Information

Number and types of customer classes Surcharge rates for BOD and TSS Average Domestic Wastewater Strengths

for BOD & TSS Strength ranges for BOD & TSS














Domestic Wastewater Strength is Increasing.






Benchmarked BOD value categoriesID Classes BOD Average Difference % Diff

1 Soft Water Service 3

2 Synthetic Material Manufacturing 30 27 90%

3 Metal Coating 80 50 63%

4 Primary Metals Manufacturing 90 10 11%

5 Inorganic Chemicals Manufacturing 95 5 5%

6 Car Washes 117 22 19%

7 Earthenware Manufacturing 120 3 3%

8 Professional Office 130 10 8%

9 School & College 133 3 3%

10 Department & Retail Stores 150 17 11%

11 Residential 175 25 14%

12 Laboratories 190 15 8%

13 Domestic Waste (sanitary strength ww) 200 10 5%

14 Nursing Homes 207 7 3%

15 Medical Facilities 223 16 7%

16 Transporters 227 4 2%

17 Equipment Service Facilities 232 5 2%

18 Repair Shop & Service Station 248 16 7%

19 Laundromats 250 1 1%

20 Other 270 20 8%


Benchmarked BOD value categories (contd.)ID Classes BOD Average Difference % Diff

21 Industrial 300 30 10%

22 Hotels/Motels without Dining Facilities 310 10 3%

23 Hotels/Motels 330 20 6%

24 Car Dealers 339 10 3%

25 Multi-User Facilities 348 9 3%

26 Pulp & Paper Products 349 1 0%

27 Fats and Oil Processing 403 55 14%

28 Hotels with Dining Facilities 420 17 4%

29 Drum Cleaning 503 83 17%

30 Commercial Laundry 517 14 3%

31 Schools (kitchens for other schools) 545 29 5%

32 Funeral Homes 594 49 8%

33 Drug Manufacturing 620 26 4%

34 Fast Food Service 623 3 0%

35 Beverage Manufacturing & Bottling 748 126 17%

36 Ink & Pigment Manufacturing 756 8 1%

37 Service Stations with RV dumping facility 770 14 2%

38 Market with Garbage Grinders 800 30 4%

39 Meat Markets 824 24 3%

40 Grain Mills 829 5 1%


Benchmarked BOD value categories (contd.)ID Classes BOD Average Difference % Diff

41 Bakeries 840 11 1%

42 Fruit & Vegetable Processing 869 28 3%

43 Restaurants 893 25 3%

44 Rendering Tallow 910 17 2%

45 Sugar Processing 998 88 9%

46 Grocers 1,032 35 3%

47 Auto Steam Cleaning 1,150 118 10%

48 Eating Places 1,150 0 0%

49 Molinos 1,187 37 3%

50 Slaughterhouses 1,210 23 2%

51 Commercial 1,215 5 0%

52 Restaurant, with Seating and China 1,222 7 1%

53 Industrial Laundry 1,341 119 9%

54 Cleaning & Sanitation Products 1,400 60 4%

55 Dairy Product Processing 1,414 14 1%

56 Paint Manufacturing 1,441 27 2%

57 Meat Products 1,624 184 11%

58 Leather Tanning & Finishing 2,920 1,296 44%

59 Specialty Foods Manufacturing 3,881 961 25%

60 Drum & Barrel Manufacturing 4,300 420 10%

61 Septage Hauler 5,400 1,100 20%


Benchmarked TSS value categories

ID Classes Average TSS Difference % Difference

1 Laundromats 132

2 Meat Markets 134 2 1%

3 Funeral Homes 135 1 1%

4 Multi-User Facilities 138 3 2%

5 Nursing Homes 139 1 1%

6 Fast Food Service 218 79 36%

7 Car Washes 229 11 5%

8 Car Dealers 240 11 5%

9 Hotels/Motels 244 4 2%

10 Bakeries 288 44 15%

11 Grocers 295 7 2%

12 Transporters 300 5 2%

13 Restaurant, with Seating and China 314 14 4%

14 Restaurants 348 34 10%

15 Molinos 393 45 11%

16 Industrial 400 7 2%

17 Commercial 405 5 1%

18 Eating Places 441 36 8%

19 Equipment Service Facilities 718 277 39%









City of Dallas Database Info

Dallas Water Utilities Bill System DWU Pretreatment & Laboratory Services City of Dallas Environmental Health Department City of Dallas Development Services

Department – Building Inspection Division


Project Database


Categorization Process Used only the “Certificate of Occupancy” database Data extract included years from 1979 to 2006 Inspected all 153,684 records to remove address

duplicates to 73,965 records Removed all Land Use categories that had <= 10

businesses (~8.97 %) as not relevant Reclassified resulting Land Use categories in to 35

Categories Of the 35 Categories we are interested in sampling 24

categories (27% of businesses in Dallas)









Land Use categories identifiedCategory Total Businesses

Airport 64

Amusement 616

Animal 98

APARTMENT 7709

ART GALLERY 42

AUTO 1800

BAKERY 26

Bar 463

BARBER SHOP 232

CAR WASH 130

CATERING 276

CHILD CARE FACILITY 299

CHURCH 1203

CONVENIENCE STORE 18

Deli 26

DONUT SHOP 12

DRY CLEANERS 418

FAIRGROUNDS 15

Yard 248

FARM 77

Category Total Businesses

FIRE STATION 22

GAS Station 148

HOSPITAL 1692

HOTEL 379

Manufacturing 1205

N/A 6697

Office 35772

Park 63

Parking 620

RESTAURANT 2380

RESTAURANT W DIRVE IN SERV 351

RESTAURANT WITH DRINKS 115

RESTAURANT WITH DRIVE-IN SERVICE 258

Retail 9337

SCHOOL 534

Tower 620

Grand Total 73965









Sampling Methodology

Initial accuracy requirements Confidence 90%, 5% accuracy for the mean 24 hour composite for each sample site (15

minute intervals)

Implies Categories 24 Each category mean to be 90% confident,

5% accurate = 2961 total samples So ~ $Very Expensive


Reducing Cost Considerations

Number of samples Sampling methodology Number of categories Supporting software Accuracy desired/required Number of iterations


Options – Cost is a function of accuracy Maximum Accuracy is 10% 90% Confidence that a sample is within 35%

siredAccuracyDec

p

confidenceZ

Population

SSSS

NoSamples

c

ppzSS

5.0

)%90(645.1

11

)1(2

2 Accuracy No of Samples ~Cost

10% 1113 $ 1,113,000

15% 581 $ 581,000

20% 357 $ 357,000

25% 242 $ 242,000

30% 181 $ 181,000

35% 139 $ 139,000

40% 115 $ 115,000

45% 93 $ 93,000

50% 72 $ 72,000









Sampling Plan Plan to do field work Iteratively (minimizes cost)

Field Investigations• Conduct Sample study• Analyze and create categories• Determine need to refine number and quality of

categories • Determine additional accuracy of data required

Field Sampling• Conduct Sample Study• Analyze and create categories


Surcharge Class Study Phase II

Customer Survey Design Survey Distribution Field Sampling & Data Validation Statistical Analysis Reporting Final Recommendations


Cover Letter – Drivers Do not cause alarm in the public about waste water rates

increasing Attempt not to bias the survey results Survey and the sampling should not end up on the council

agenda or evening news Survey methodology should be mathematically sound Survey responses should enable physical sampling

activities Survey response rate target of 10%


Survey Design Structure / Principles

One questionnaire for all participants Keeping the questionnaire short Logical grouping of questions Multiple choice questions No questions related to water rates Privacy will be maintained of the data


Survey Sections

Business information Validation Validate the physical business address Validate business category type Hours/season of operation Sampling can be done when the business is

generating waste

Water Equipment Rate Class Related Physical sampling

Restrictions that would hinder setting up a sampler


Survey Sections - Business information1. Name of the respondent ?

Text field2. Job Title of respondent ?

Text field3. Type of business ?

The 25 Categories Other – Text field

4. Do you rent the facility ? Yes/No

5. Do you operate your own laundry ? Yes/No

6. Do you operate dishwashers ? Yes/No

7. If you serve food at your establishment ? Yes/No

8. Do you serve food primarily in disposable containers ? Yes/No

9. Does your business have a drive through ? Yes/No

10. Is your business a mixed use facility ? Yes/No

9. If you are a mixed use facility, What other business types do you have on premises ?1. The 25 categories


Survey Sections - Hours of Operation Hours of Operation

1. Is your Business Seasonal Yes/No

2. If seasonal what season is your business open School holidays Summer Winter

3. Is your business open 24 hrs Yes/No

4. Normal Business Hours ( except weekends) Operating Hours S_M_T_W_T_F_S

Number of Shifts __ 5am to 9am 8am to 5pm 9am to 9pm 10am to 9pm 10am to 8pm 10am to 6pm 11am to 2pm


Survey Sections – Water Equipment

Water Equipment1. Do you have a split water meter ? i.e. D you share the

meter with another business establishment/renter ? Yes/No

2. Is there more than one water meter at your facility related to your business ? Yes/No

3. Do you operate a grease trap ? Yes/No

4. What is the size of the meter ? ½ inch ¾ inch 1 inch


Survey Sections – Rate Class

Rate Class1. Do you get a water bill by the city ?

Yes/No2. Do you share a meter with another entity?

Yes/No3. Is your water cost included in your rent ?

Yes/No


Survey Sections – Physical Sampling

Physical Sampling1. Do you know the location of the cleanouts ?

Yes/No2. Is the cleanout located in a drive way or parking area ?

Yes/No3. Is the drain line form you business also used by another

business ?

Yes/No4. Would you volunteer for the Dallas water utilities to sample

your waster water for 24 hrs, at no cost to you ?

Yes/ No





Mailing List – Process Number of mailings computed based on

5% return rate and number of sites to sample

Additional Mailings based on weighted distribution

Target 4000 mailings


Mailing List – Target


Restaurant with Drinks – Sites Map

In Progress


Fast Food – Sites Map

In Progress


Survey Results – We Succeeded !!! Expecting < 400 responses or 10% of mail outs Issues,

Duplicate, Blanks, No Longer There, Returns Only 691 viable to be entered in the database


Number of surveys received


Understanding Survey data The Dallas Certificate of Occupancy database

was incorrect


Distribution of Responses by CO Category


Survey Results – Data Entry & Validation

Enter data in excel then transfer to Access Database

Scan paper copy into the file server Data Entry Effort - 10 surveys per hour Some people also sent back the cover page

increasing weight and postage Originally we had $224 in the budget for

postage actual cost $700+ Increase in Data entry time from 40hrs estimate

to 100+ hrs


Survey Results – Data Entry





Effects on Field Sampling Plan Do we have enough business to warrant

sampling All except Coffee shops that only have 2 in the survey

response

Are the business close enough in expected results that extra sampling is not needed Retail Schools w/o kitchen Churches Offices All have BOD between 130 - 150, TSS – 80 - 150


Survey Analysis Procedure Identify responses with the following

Deli Vet/Hospital Boarding Auto Washing Bar Barber Shop Catering Coffee shop

Mark facilities that are multi use low priority Remove facilities that are seasonal Remove facilities that have water bill included in rent Prioritize based on knowledge of sewer cleanouts Prioritize based on water treatment devices Generate map in Google

Churches with kitchenRestaurantsLaundry/Dry CleanersHotel with restaurantRetail – food relatedSchool with kitchenFuneral home


Identifying the Sample Sites For each category

Remove multi use sites Remove seasonal facilities randomly pick twice the number of sites required Remove facilities that have water bill included in rent

Prioritize based on the knowledge of sewer cleanouts Prioritize based on water treatment devices If we are short of sites pull from the CO database Generate map in Google Schedule site visit for sampling for each site


Potential Survey Sites


Survey sites – Fast Food


Survey sites – Restaurant with drinks


Field Survey - Overview Develop the forms for site inspection

Pictures of the site Pictures of the water meter showing the reading Pictures of the sampler installed GPS coordinates of the sampler on site Facility code Weather conditions Time reached facility Time Sampler turned on Time Sampler picked up Sampler condition


Field Survey - Overview Site Recon (280 Recons for 139 Samples)

Is the site suitable for sampler install Criteria ? Saves cost by not having a sampling crew out there

Field Crew route planning Save cost on drive time Sampler pre programming Battery charge

Sampler - two crews Three sites per day, per crew, 6 days a week

Data analysis Report generation, review & finalization


Field Issues

Site contact is unaware or unwilling to direct us to grease trap and/or cleanout locations

Cleanouts are covered with asphalt/concrete or are highly corroded and can not be removed

Grease traps and cleanouts are located within drive-thru or parking lot areas

Property is located within mall or office building Field teams can not locate cleanouts High probability of sampler theft Funeral Homes unwilling to let us in Very few Donut shops not in strip malls


Suggestions for Effective Field Sampling

Assistance from City if site contact is unwilling to allow site access Funeral Homes

Sampling executed in sanitary sewer side of grease trap if cleanouts can not be accessed?

Strip Mall businesses Donut shops Dry cleaners Coffee shops

To deter sampler theft, samplers will be chained and locked to a secure object if possible

Grab Samples?





BOD Results TSS Results

Customer Category AverageAdjusted Average Median Average

Adjusted Average Median

Dry Cleaner 243.33 240.25 249.00 131.00 97.25 96.00

Auto 729.67 423.00 447.00 279.33 148.25 149.50

231 / 1150 218 / 1250

Car Wash 127.20 140.50 125.00 137.00 152.50 86.00

63.00 204.00

Amusement 477.83 382.00 390.50 184.50 177.50 162.50

200.00 250.00

Deli 610.50 531.75 621.50 198.50 195.75 198.50

623 / 800 334 / 800

Bakery 1260.33 947.50 790.00 217.17 211.50 195.00

988.00 662.00

Restaurant 809.17 720.00 762.00 378.67 215.00 137.00

961.00 600.00

Animal 331.83 323.75 286.50 313.00 247.50 226.50

Grocery 916.00 816.50 636.00 313.67 264.50 233.00

916.00 548.00

Barbershop 244.50 184.00 157.00 386.33 277.25 128.50

Bar 921.00 563.50 521.00 275.17 283.00 310.00

311.00 216.00

School 601.50 466.25 208.50 430.17 339.00 314.00

330.00 112.00

Convenience 2073.33 1335.00 1223.00 352.50 342.50 343.00

1215.00 405.00

Restaurant w/Drinks 1285.83 1146.50 1017.50 406.17 361.50 344.50

1222.00 314.00

Coffee Shop 2127.17 1965.50 1507.00 771.83 406.75 404.50

Fast Food 903.83 906.75 1052.00 545.17 438.75 423.50

623.00 334.00

Hospital 1479.17 1104.00 645.50 568.40 452.33 424.00

Funeral Home 1071.60 416.67 374.00 591.80 484.33 626.00

635.00 562.00

Catering 1748.20 1514.67 1620.00 841.33 618.50 558.00

Hotel-Motel 2758.20 2009.00 1054.00 779.33 669.50 400.00

500.00 627.00

Sampling Data Statistical Analysis


Additional Sampling Evaluation

Hotel / Motel had significant variation - onsite restaurants vs. continental breakfast

Some sampling and testing determined non-representative

Additional samples needed to provide statistical numbers

Some classes had large variations


Additional Sampling Recommendations

Hotel/Motel with Restaurant – 2 Hotel/Motels without Restaurant – 3 Bakery – 2 Funeral Home – 3 Auto – 2 Bar – 1 Hospital – 2





Customer Class Sampling Results

Customer Class BOD TSS

Hotel/Motel without Restaurant 219 273

Funeral Home 362 247

Auto 409 270

Bar 446 217

Deli 611 199

Grocery 836 323

Fast Food 904 545

Restaurant 1,026 353

Hospital 1,132 452

Bakery 1,432 206

Catering 1,748 841

Convenience 2,073 352

Coffee Shop 2,127 772

Hotel/Motel with Restaurant 2,223 568





Customer ClassGroup 1 – Domestic Strength

Group 1 (Domestic Strength) Residential Hotel/Motel without Restaurant Funeral Home Auto Amusement Animal Barbershop Car Wash Dry Cleaner Schools


Customer Class – Groups 2-4

Group 2 (BOD = 450 mg/L, TSS = 200 mg/L) Bar

Group 3 (BOD = 700 mg/L, TSS = 250 mg/L) Deli Grocery

Group 4 (BOD = 1,000 mg/L, TSS = 450 mg/L) Fast Food Restaurant Hospital


Customer Class – Groups 5-7

Group 5 (BOD = 1,400 mg/L, TSS = 200 mg/L) Bakery

Group 6 (BOD = 1,950 mg/L, TSS = 800 mg/L) Catering Coffee Shop

Group 7 (BOD = 2,150 mg/L, TSS = 450 mg/L) Convenience Hotel/Motel with Restaurant


Significant Industrial Users Surcharge – Group X

SIUs are sampled and managed through DWU Pretreatment & Laboratory Services

SIUs are not a customer class as currently defined in the City Ordinance


Future Steps

Dallas Water Utilities calculates new wastewater billing rates for Customer Classes

City of Dallas Ordinance is updated with new Customer Classes

Billing systems are updated Certificate of Occupancy forms are updated to

identify Customer Class as new business are added


Morgan Dadgostar, Dallas Water Utilities, [email protected]

Jennifer Ivey, Malcolm Pirnie Inc., [email protected]

Randy McIntyre, Malcolm Pirnie Inc., [email protected]

Documents

INDEPENDENT ENVIRONMENTAL ENGINEERS, SCIENTISTS AND CONSULTANTS 25 th Annual Region VI Pretreatment Association Workshop August 5, 2009 Wastewater Rate