Manhole versus Catch Basin runoff - Town Petition, Cranston, RI

[sarena]

1950 development of 250 homes were built in this community. 8" pipes leading from the house go to the main sewer connection. Manholes in the middle of the street versus newer built-in-sidewalk catch basins are used for the collection of rain/snow water and is the vehicle for moving water int his community. Town is claiming these are manholes and the City would not be responsible for maintaining, unless there is a problem. In otherwords, no preventative maintainence is done on these and they are only responsible to address when there is an issue. If residents are paying sewer taxes for maintainence of sewers and catch basins, isn't it fair to say this manhole that fills up with dirt and leaves (a lot) would be considered a catch basin as it is the only vehicle for keeping water flowing through the community? (There seems to be 2 theory's to what a catch basin/manhole does.) The second question is the City sent notice to residents to install a back flow proctector, wouldn't this only work if the City was maintaining the sewers and catch basins? Any help is appreciated.

 

[cvg]

a "catch basin" catches water and is the inlet point into the drain for runoff. A "manhole" is a structure used to allow entry by a man into the drain. They are also used to allow angles in the pipe and as a connection structure for lateral pipes to join the mainline. They are rarely used to catch water unless a grated cover is provided.

Typically the City is responsible for maintaining facilities within the right of way, and the property owner for the pipes within his property.

 

[Maury]

The City should be responsible for maintaining a public sewer system. Whether they call the structures manholes, catch basins, or inlets is irrelevant. The city could be liable for damages due to negligence(lack of maintenance).

I agree with cvg as to the definition of a manhole. Storm water is usually collected by catch basins or inlets rather than manholes. The difference between a catch basin and an inlet is that the catch basin has a sump for collection of silt and debris. Many manholes do have grates rather than solid lids.

 

[cvg]

In this area, catch basins are not constructed with sumps. The floor of the catch basin is shaped to provide posative drainage to the outlet pipe and the silt is expected to be conveyed through the system to the outfall. In areas where heavy sediment loads are expected, such as in the urban fringe where upstream watersheds are undeveloped, a sediment trap is often provided to catch the sediment.

In general the manholes on the mainline drain are near the center of the roadway and with a crowned roadway, very little water will flow over the manhole lids, therefore they don't have grates installed. The catch basins are generally placed at the gutter. Drains from adjacent property are generally discharged to retention basins which bleed off with a connection to the catch basin or manhole.

 

[LHA]

Is this a combined sewer (sewage and rainwater)? It sounds like it.

Either way, if there is an O&M agreement regarding the structures (any structures...cvg and maury are correct, it is irrelevant what they are called or what they do), it will spell out who has to do what. If there is none, and 50 years ago, there often was none, then the municipality must do due diligence to protect the citizens. The case could be made that due diligence is responding to and correcting malfunctions. If there is no O&M on the structures, there is no inherent obligation to do preventative maintenance.

You indicated the taxpayers are paying for maintenance. This implies there is some type of O&M Agreement. But just because you pay taxes, doesn't mean the duties include maintenance. It just means you are paying to use the utility, as allowable by RI's Public Utilities Commission. You should consult them to see what is required for a municipality to collect taxes, but it probably only the provision of that utility, not preventative maintenance.

Backflow preventers should help, but they are not full-proof against all backflow.

 

[dicksewerrat]

There is an 8" pipe from each house or from the development to the sewer main? The developer may have never turned the developer-built infrastructure over to the city. The taxes paid are probably only for the O & M of the City collection system not the pipes and structures on private, ie. development property. You may want to find out who repairs the streets. Who plows the snow? etc. If the City is doing the maintenance on the streets inside the development, they probably took over the sewer mains and water mains also.

 

[sarena]

Thank you very much, this is consistent information with what previous threads on the subject and research I have done on this. This was very valuable to the Residents, I thank you all. Happy Holiday!

Sarena

 

[sarena]

Thank you very much for this information. This is consistent with what prior threads have said on this subject, as well as, research on the matter. I will contact the RI Utility Commission. The residents of Cranston thank you for your assistance.

Happy Holiday.
~Sarena

 

[KRSServices]

May I add one more item?

Your thread mentioned the fact that the Town/City is requesting that backflow prevernters be installed. In my opinion, this is cheap insurance in case of a blockage. If this seweeer has been operating for 50 years, it was either well designed to ensure that sufficient scour is present such that the buildup of debris in the invert of the pipe is not occurring, or, there have been some problems or history of backups.

either way, I suspect the latter and would suggest that as a ratepayer...one of the 250 residents...I also wouls suspect that you would not want to see the bill for replacement of this sewer....or some extensive maintenance, as you suggest. The backflow preventer is probably the next best solution as opposed to a costly upgrade.

KRS Services

http://www.krs-services.com