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Private Sewer Laterals: What's Going On?

With the passage last year of a new Private Sewer Lateral Ordinance, the previous Town Council codified longstanding but unevenly-enforced policies regarding the inspection and repair of private sewer laterals. There has been robust discussion in the community about the implications of this action, and many questions raised about this complex issue. Here is a primer on the situation:

What are laterals?

Private sewer laterals (PSL or laterals) are the pipes that carry sewage from your home to the sewer main lines that run under the streets. They generally start at your foundation and end under the middle of the street outside your house. Ultimately, all our sewage is pumped to the Central Marin Sanitation Agency's sewage treatment plant on Andersen Drive in San Rafael.

Who's responsible for them?

Your lateral is an integral part of your house, just like the roof or driveway, and per municipal code, it is your property. (This is the way it's always been in Corte Madera, and the way it's done in the vast majority of cities and towns nationwide.) If you didn't own and maintain a sewer lateral, you'd be paying to own and maintain a septic system—yikes!

Widespread failures

Virtually all our sewer laterals need to be replaced; of about 200 sewer laterals inspected in the last year, all but two had failed! This is largely because many of the sewer laterals in Corte Madera are made of clay, and as you can imagine, clay pipes easily crack and break as the land settles and moves (if you're struggling to think of a worse material to make sewage pipes out of, they used to be wood!)

The price of inaction

PSL failures pose a range of unacceptable threats to the community. Broken laterals allow raw sewage to leach into the groundwater, posing a public health threat. Because Corte Madera sits right on the Bay, much of this contamination ultimately ends up in the Bay and is extremely toxic to the environment.

Broken laterals also allow rainwater to enter the sewer system, which costs residents in multiple ways. First, we pay for sewage treatment by the gallon; when rainwater enters the system during wet weather, residents must pay to treat not only their sewage, but also all that rainwater. Second, during periods of heavy rain, the increased flow can overwhelm the treatment plant's capacity, forcing the plant to send untreated water into the Bay. This incurs heavy fines from state authorities—which is ultimately passed on to ratepayers. Finally, it is not uncommon for rainstorms to increase the amount of sewage entering the treatment plant by a staggering 1500% or more. This taxes our infrastructure, costing more money in repairs and upgrades.

The PSL ordinance

We've long known that repairing the dilapidated laterals throughout town is critical to shoring up our sewer infrastructure, preventing contamination, and ultimately saving money. After decades of taking a somewhat scattershot approach to requiring lateral repairs, the state water treatment board decided in 2018 that Corte Madera needed to codify a regular system for initiating repairs or face a hefty fine. In response, the previous Council passed the Private Sewer Lateral Ordinance last June.

Triggers for inspection/repair

The ordinance set four triggers that can require residents to have their laterals inspected (and, given the condition of most laterals in town, likely repaired or replaced). They are:

  • selling your house (or otherwise transferring ownership)

  • doing $50,000 or more worth of renovations within a 3 year period

  • when the road or sewer main that serves your house is worked on

  • when failure of a lateral poses a public health threat

Easing the burden

Repairing a sewer lateral is expensive. Depending on a number factors (e.g. length and condition of lateral, topography of site, how busy a street your house is on), the price for a property owner to repair or replace their lateral could range from $5,000 to more than $15,000, and with virtually all laterals in need of repair, many of our homeowners now see this expense somewhere on their horizon.

The Town does not take this burden lightly, and there are ways we can help. In late January, we held a public workshop kicking off the development of a program to provide financial assistance to homeowners needing to repair their laterals. This program will likely have two main elements:

Economies of scale

The first element involves coordinating with groups of homeowners who live on the same street, and having them all do any necessary repairs at the same time, while work is already being done on their street. This would likely cut costs by 20-40%, allowing a contractor to repair all the failed laterals on a street while already doing other work on that street, and avoiding the need to cut into and patch the road surface later.

I will propose granting a waiver to any homeowner whose lateral work is triggered when their lateral work could be delayed so as to be done at the same time as an impending capital improvement project on their street (provided their lateral does not pose a public health threat).

Grant money for repairs

The second element involves establishing a grant program to help homeowners of all income levels pay for any lateral repairs that may be required, with grant money coming from our existing sewer budget (there is already a PSL grant program for lower-income homeowners). The Town does not have the funds to pay for all lateral repairs, but we are happy to look for ways to contribute to the effort, especially for the portions of laterals that are under roadways and not on private property.

Going forward

In the coming weeks, we request and welcome the community's input to help us develop the program that is most beneficial to homeowners facing lateral repairs. While recent regulatory decisions at the state level have limited the Town's flexibility on when to require repairs, we remain committed to finding the most effective use of the Town's limited resources to help alleviate the burden on homeowners.

Some helpful links:

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