Upgrades to Existing Lift Station

[jgute]

All:
This is my first post. I'm a civil engineer in Jackson, WY, and have been asked to be on the board for a new ISD being formed for our neighborhood. There is an existing lift station, serving approx. 50 homes, that requires frequent maintenance to clear rags, dog toys, etc. from the pumps (Hydromatic S4NX Explosion Proof Submersible). A local engineering firm has proposed installing grinder pumps in place of the existing pumps ($13,000+/- and a lot of maintenance), or installing a grinder unit upstream of the existing pumps ($35,000+/-). Is this a wise approach, or are new or more industry standard technologies available that should be considered? The HOA is considering videoing the existing system to try to identify the homeowner(s) in question, which may be a challenge. There's about 20ft static head on the pumps, the gravity in is 8-inch PVC, and the pressure line is 4" and approx. 1300 ft long. Any input would be greatly appreciated. Thanks!

 

[bimr]

It is a reasonable solution to install grinder pumps. You should note that the maintenance on grinder pumps may be higher than standard pumps.

Installing a separate grinder will not be cost effective.

You may consider replacing the pumps as the pumps fail. Many lift stations keep a spare pump on the shelf.

Sending out a news letter on what should not be flushed is probably more cost effective than trying to find the culprit with a video camera.

 

[jgute]

Thanks for the info. The HOA has addressed the problem several times in their monthly newsletter, but the problem persists. Maybe some people just don't read their mail...

 

[KiwiMace]

Having retrofitted them into municipal projects on a couple of occasions, I am in the pro-grinder camp.

Provided the lift station is physically able to accommodate them, the upstream grinders are very effective and readily installed in a channel or piped installation with minimal head requirement.

$35k is not a lot of maintenance visits. Municipal projects easily absorb that kind of capital sum, but yours is private and you need to look at the budget you have.

The video idea is a joke. Send a newletter saying that the HOA will need $700 each for the grinder and see if they read it then.

 

[Artisi]

For sewage lines you must always cater for the idiots, send as many letters as you like but you will always have undesirable trash being flushed into the system.
The only way to overcome the problem is self-cleaning trash racks(probably beyond the budget for such a small operation) or a grinder on the inflow
Google - Muffin Monster for info.

It is a capital mistake to theorise before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts. (Sherlock Holmes - A Scandal in Bohemia.)