Wastewater is a non-metered service, and therefore, there is no exact way of determining how much wastewater goes down drains and toilets for individual customers. Like most utilities, Colorado Springs Utilities calculates projected wastewater flows by using a consistent formula for all residential customers.
Colorado Springs Utilities uses two different approaches to bill wastewater services based on two periods.
Winter Period – Approximately December through February (exact dates vary based on billing cycles) billing units are equal to the actual metered water consumption for the billing periods that include dates in December, January, and February. Since billing periods do not align with calendar months, parts of November and March will be included in the winter average period. In some cases, the last few days of October or the first few days of April may also be included in the winter average period.
More specifically, your winter period will begin within a few days before or after your meter read date that falls between October 28 and December 1. When you get your bill in October, look (usually on page 3) to see when "your next scheduled Meter Reading date is." For example, if your meter reading date is 11/06/09, your winter period will begin within a few days before or after November 6. If your meter reading date is 11/20/09, your winter period will begin within a few days before or after November 20.
Your winter period will end within a few days before or after your March meter read date, which will be indicated on your February bill.
Summer Period – Approximately March through November (exact dates vary based on billing cycles). The amount of wastewater billed from approximately March through November is equal to the average of your winter period usage or actual metered water use for the current billing period, whichever is lower.
Because billing periods do not align with calendar months, billing periods that overlap into summer period months (November and March) are prorated.
Winter Period Billing Detail
If a billing period includes both November and December dates in the same billing period, the total consumption is averaged by the number of days in the billing period to determine the Average Daily Units (ADU) for that billing period. The November dates are then billed using the summer methodology (see below), and the December dates are billed using the winter methodology which is equal to water consumption.
Example: Account # ********04
Billing Period – November 17 – December 18 = 31 days in billing cycle
Total Consumption – 155 Cubic Feet (cf) of water
ADU = 155 cf of water/31 days = 5 cf ADU
Proration: November = 13 days/December = 18 days, therefore:
13 days billed at the previous winter period average or actual water consumption, whichever is less.
In this case, since the actual consumption is less than the previous winter period average (see Winter Period Average Calculation example below), the lower amount (5 ADU) is used.
18 days billed at actual water consumption for month of December. In this case, 5 ADU.
Winter Period Average Calculation
Winter Period ADUs are calculated first by determining the ADU for all billing periods with December, January and February consumption. All billing periods with December consumption are used to determine the December ADU; all billing periods with January consumption are used to determine the January ADU and all billing periods with February consumption are used to determine the February ADU. Since billing periods do not align with calendar months, parts of November and March may be included in the winter average period. In some cases, the last few days of October or the first few days of April may also be included in the winter average period.
All three ADUs are then averaged to determine the Winter Period Average.
The Winter Period Average may include shoulder months (October, November, March & April), depending on billing cycles. Exact dates and months for the Winter Period Averages vary based on billing cycles.
Example – Account # ********04
To compute December ADU: Use billing dates November 17-December 18, 2008 and December 18- January 21, 2009
Nov 17-Dec 18: 155 cf & Dec 18- Jan 21: 190 cf
345 cf/65 days= 5.31 ADU
To compute January ADU: Use billing dates December 18- January 21, 2009 and January 21- February 22, 2009
Dec-18-Jan 21: 190cf & Jan 21- Feb 22: 140 cf
330 cf/66 days= 5.00 ADU
To compute February ADU: Use billing dates January 21- February 22, 2009 and February 22- March 23, 2009
Jan 21-Feb 22: 140 cf & Feb 22- Mar 23: 980 cf
1,120 cf/61 days= 18.36 ADU
All three monthly ADU averages (5.31, 5.00, and 18.36) are averaged together to come up with 9.56 ADU for the Winter Period Average.
Applying your winter average water use minimizes wastewater charges on irrigation and other outdoor water use as much as possible. Historically, November through March are seasonally low water use months.
Metered water usage in portions of November and March may be included in the winter average.
The last few days of October or the first few days of April may also be included in the winter average.
Billing periods do not coincide with the calendar month. Bills are generated and mailed after the meter read date, which can be on any business day throughout the month.
Some customers are billed near the beginning of the month, some near the middle of the month, and some near the end of the calendar month. Therefore, as is the case with most utilities, it is not possible to calculate water usage on a calendar-month basis. For instance, in order to include all of December through February in the winter average, your water usage in the last part of November and the first part of March may be included as well. Exact dates are determined by your individual billing cycle.
If I irrigate during the winter calculation period, aren’t I being penalized for watering?
It is impossible for non-metered services like wastewater to exactly or precisely measure wastewater use on a customer by customer basis. As such, utilities must determine a formula or calculation that generally reflects wastewater usage. The winter period historically has the lowest water usage, as it is primarily reflective of indoor water use and minimal irrigation. By averaging the winter period ADUs, fluctuations in water use can be generally offset. While not precise to an individual’s wastewater use, it is an appropriate and reasonable calculation to determine wastewater use.
What if I move to a new residence?
New customers and customers moving to a new residence during spring, summer or fall have no winter history available. During the summer months, they would therefore be billed for 33 average daily units (ADU) of wastewater each month or their actual metered water use, whichever is less.
I was out of town and used no water in December. How will my winter average be calculated?
If water usage for a winter month billing period is zero, the ADU is set at 33 for that billing period. This amount would then be averaged along with the other winter billing periods to establish the winter average.
