A sump discharge line that's hooked up to the city sewer is illegal in many areas and in general is not a good idea. In this post we'll explain the reasons, why you should care, and what you can do instead.
When I first heard that pumping sump water into the sewer system was illegal, my first thought was "Why? It's just water!" and I'm sure plenty of people share the same thought. But it isn't just water; when it comes to this issue, we must think of groundwater and city water (the water that comes out of your tap) differently.
The storm drain system, designed for groundwater/rainwater, is separate from the city sewer system, doesn't go through a water treatment facility, and flows directly into the nearest body of water. Because of this, the city sewer system and its water treatment facilities are designed only to handle the demands of daily city water usage in the city's homes and businesses.
If you're a homeowner with a basement or crawl space, you're likely aware of the large amount of water your sump pump has to handle during a storm. If your pump is discharging to the sewers, that's a sizable amount of extra gallons pouring into the sewers in a short amount of time. Now imagine if sump pumps all over the city were discharging to the city sewers-- during a storm, that would be thousands of gallons of extra water pouring into the system all at once. The sewer system and water treatment facilities would quickly fill to over-capacity and easily flood during a period of heavy rainfall, causing either the sewers to back up into homes or the water treatment plant to release partially treated sewer water into local streams and rivers (ew).
If that doesn't convince you, here's another reason: A main drain/sewer clog is a fairly common problem, especially in yards with trees, and it usually happens without warning. If your main sewer suddenly stops flowing properly, it can back up into your toilets, bathtub, and sinks. The last thing you'd want in that kind of situation is a sump pump pouring gallons and gallons of additional water into the clogged sewer! You can turn off your water until you can get the sewer cleared, but you can't turn off your sump pump without risking a flood.
No one wants sewage backing up into their home, so if your sump pump is currently hooked up to the city sewer, get that fixed! You may hate the idea of having an unsightly pipe pouring water into your yard, but there are plenty more attractive options that will work with your home's current situation and landscaping, such as routing the water away from your home in a pipe underground and directing it to a drainage ditch, or even hooking it up to the storm drain system, if available.
Working with a licensed and experienced contractor like Universal Plumbing & Sewer can really help when weighing the different options. We can help you determine the best course of action for your landscaping, personal preferences, and budget while ensuring the water gets carried far enough away that it doesn't return to your basement. Call us at (586) 459-0040 for more info, or click here to read more!