From:
To: City Council
Subject: Comment- Sewer Rates That Account for Gray Water Date: Monday, April 22, 2024 10:40:50 PM
Hello Sebastopol City Council,
I've reviewed the materials related to water and sewer rates and commend staff for providing a much more complete summary and discussion.
Given the magnitude of the proposed fee increases, I support Option 2.
I am also in support of the tiered rate structure for water use. One adjustment that I recommend is that parcels with two units, such as a single family dwelling (SFD) and an accessory dwelling unit (ADU), should have tiers that are 1.5 times that of a single dwelling parcel. So, for a parcel with a SFD and ADU, instead of the cutoff between tier 1 and tier 2 being 8,000 gallons, it should be 12,000 gallons. Otherwise those that have built ADUs and provide low income housing are likely to pay higher water rates, which is not fair and does not support development of ADUs.
My primary comment is to urge Council to include a provision to account for graywater use when calculating sewer flows.
The fee study should include a provision that specifically allows graywater use to be quantified in order to improve estimates of how much water is being sent to the sewer. Currently there is an equation that uses water use from winter months (when there is limited irrigation) to estimate water that goes to the sewer. The equation is intended to estimate indoor water use that in most homes flows down the drain to the sewer. This is reasonable and fair because water that is used for irrigation does not go to the sewer and you should not be charged as if it does. However, the current methodology does not consider sites with graywater systems that divert laundry or shower water from the sewer and discharge the relatively clean water to the landscape. Graywater does not go to the sewer and you should not be charged as if it does.
The fraction of water diverted away from the sewer and to the landscape can be substantial.For example, laundry water use is estimated to use about 15% of indoor water use. Thus, for sites with laundry to landscape systems, estimated sewer discharge should be lowered by perhaps as much as 15%. Those that have laundry to landscape (and other graywater systems) are being severely overcharged for sewer use. In my case the savings could be approximately $15 a month (under existing rates), which translates into a one year return on investment! More complicated systems that divert bath and shower water would likely have longer payback periods, but these systems would undoubtedly become good financial investments if estimated sewer discharges were appropriately calculated to account for graywater.
There is tremendous potential to incentivize water conservation through a relatively simple program that inspects graywater systems and more accurately estimates the volume of water that is sent to the sewer. Graywater system inspections could be supported by a separate fee that covers those added program costs. Use of graywater has additional benefits, not only does it reduce sewer flows and demand on our sewer infrastructure, but it also reduces irrigation demand and recharges groundwater. I hope you see the tremendous potential benefit through this type of program and direct staff to include a provision to account for graywater system use in estimating sewer flows.
Recommendations
1.Support Option 2
2.Adjust tiers for parcels with two or more units on a single meter
3.Account for graywater use in estimating discharge to sewer Thank you for your service,
Robert Pennington