Sewer Surcharge Calculation
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Sewer Surcharge Calculation

Stand Alone Sewer Surcharge Rates

The Sewer Surcharge is calculated using Stand Alone Uniform Sewer Rates. This is made up of the Wastewater Fixed Charge that is based on the size of the meter connected to your address and a Wastewater Consumption Charge based on water usage. In order to exclude increased summer water usage that is estimated not to be returned to the sewer system, the water usage for the wastewater consumption charge will be calculated as the lower of actual water usage or the winter average usage.

The Fixed Sewer Surcharge rates by meter size are listed below:

Fixed Sewer Surcharge Rates 

Residential Accounts

Stand Alone Fixed Sewer Charge
$17.38

Commercial Accounts

Meter Size Stand Alone Fixed Sewer Charge
1"/25mm $108.11
1 1/2"/40mm $253.26
2"/51mm $422.76
3"/75mm $759.81
4"/100mm $1,345.45
6"/150mm $2,456.70
8"/200mm $4,093.34
10"/250mm $6,743.23

 

2019 approved rates for both residential and commercial customers are outlined in the table below:

Typical Residential Customer

Sewer Rates
2018 Residential Rates
​2019 Residential Rates
Waste Water Fixed Charge
$15.84
​$17.38
Waste Water Consumption Charge
$2.48 per cubic metre of water used (reduced for excess summer consumption)
​$2.90 per cubic metre of water used (reduced for excess summer consumption)
 

Typical Commercial Customer

Sewer Rates
2018 Commercial Rates
​2019 Commercial Rates
Waste Water Fixed Charge
$80.46 for typical 1” service
​$108.11 for typical 1" service
Waste Water Consumption Charge
$0.85 per cubic metre of water used (reduced for excess summer consumption)
​$1.20 per cubic metre of water used (reduced for excess summer consumption)
 

How is the sewer surcharge calculated?

The sewer surcharge is charged to owners or occupants of land in the City of Windsor who have access to a sewage system and is calculated as follows:

  1. The wastewater fixed charge is based on the size of the meter (see table above);
  2. For the period from November 1 through to April 30 (known as the winter consumption), the actual consumption of water is charged at a rate per cubic metre of water.
  3. For the period from May 1 through to October 31 (known as the summer consumption), the actual summer consumption of water is also charged at a rate per cubic metre but is reduced by any excess summer usage above the winter average usage consumption of water. (Note: Therefore, charges do not include increased summer consumption costs related to watering the garden, filling pools, washing cars, etc. during this period).

Examples:

Residential Customer Using 18 m3 of water/month in the summer and with a winter average of 12 m3 of water/month

The fixed charge portion of the sewer surcharge will be $17.38 for residential customers.

The consumption charge portion of the sewer surcharge is calculated as follows: 

  • Actual water usage (18 m3 of water at $2.90/m3) $52.20
  • Reduction for excess summer usage (6m3 at $2.90/m3) ($17.40)
  • Total Waste Water Consumption Charge $34.80
  •  Total Waste Water Charges (Fixed + Consumption) $52.18 

Commercial Customers Using 1000 m3 of water/month in the summer and with a winter average of 900 m3/month

The fixed charge portion of the sewer surcharge will be $108.11 for a customer with a 1” service.

The consumption charge portion of the sewer surcharge is calculated as follows:

  • Actual water usage (1,000 m3 of water at $1.20/m3) $1,200.00
  • Reduction for excess summer usage (100 at $1.20/m3) $120.00
  • Total Waste Water Consumption Charge $1,080.00otal Waste Water Consumption Charge $1,080.00
  • Total Waste Water Charges (Fixed + Consumption) $1,188.11

Why does the sewer surcharge also include fixed charges and not just water usage?

Fixed charges to connect to the water system are also factored into the calculation of the sewer surcharge, as they are an integral part of the entire water distribution process. There are both costs that fluctuate with the amount of water that is discharged into the sewer system and costs that are fixed in nature that need to be funded no matter what the usage levels are. However, approximate 70% of the sewer surcharge amount is based on the amount of water actually used.

Allocation of Fixed and Variable Costs

The way the sewer surcharge is calculated was changed in 2009 to better reflect the amount of water the consumer actually uses. In order to be more closely aligned with the provincial average as it relates to the fixed/consumption fee ratio for sewer charges, the formula is based on approximately 30 percent fixed cost and 70 percent consumption cost for average residential water users. Consumers are able to better manage their sewer surcharge costs by reducing their water consumption. Lower water consumption will reduce the strain on the sewer infrastructure, which could delay the need for future capital expenditures, thus saving money over the long term.

Allocation Between Residential and Commercial Customers

Consideration was given in this year’s review to the proportion of costs assigned to residential and commercial customers. Historically, water consumption has typically been split 48% and 52% respectively between residential and commercial customers based on actual usage. The City’s model, however, historically allocated these costs at a 68% to 32% split. This allocation had been in place for several years and was essentially left status quo over the past number of years as a means to assist the business community during the economic downturn experienced a decade ago. Given the recent changing economic conditions in the city and the fact that Windsor’s commercial and industrial waste water charges fall significantly below our peers, effective in 2019 allocation of these costs will begin to move to be more reflective of actual consumption patterns. These changes will be reviewed annually and may be phased in over an extended period of perhaps five years. This change will result in some of the burden being shifted from residential to commercial customers, bringing commercial costs more in line with the provincial average.

How will sewer surcharge rates affect me? 

  • As a result, the sewer surcharge rate adjustments for the combined fixed and consumption portions of the wastewater bill may translate into a monthly increase of $8.54 in costs for the average residential customer, assuming that the homeowner's annual water consumption of 200M3 remains unchanged in comparison to 2018.
  • The trend in Windsor, as well as across the province has shown a decline in water usage. Consumers can reduce costs further through continued conservation. Therefore, the average increase will likely be lower than this amount.