SEPA and HPA Requirements

[msquared48]

I have a project referred to in another region of this forum where it is necessary to repaiir an existing foundation. The building has a four foot tall crawlsoace with the exterior stemwalls four feet high retaining earth all around the exterior full height. The structure is experiencing settling and the foundation wall has cracked. The structure has a flowing creek, four feet wide, about 50 feet to the north.

The intent is to do all underpinning work from the interior of the crawlspace with no work outside of the building limits.

My question is, would this scenario trigger an automatic SEPA and HPA review? The clients do not want to go thru the delay of the process, but I have a problem with that course if it (the SEPA/HPA process) is legally required under this scenario. Quite frankly, this one bugs me as the groundwater next to the stream cannot help but be affected by the excavating for the underpinning, some of the holes being four feet deep. I do not know if the stream is a salmon stream, but, considering the location and streamflow, consider it a very good possibility.

Mike McCann
McCann Engineering

 

[jheidt2543]

Is it possible to use helical piles and thus eleminate the excavation work? They can be installed with an attachment to a skid loader so, it could be possible to install them from inside the building through holes in the floor.

Just a thought!

 

[msquared48]

The client wants to have the building operational during the fix, so, unfortunately, no. Thanks though.

This same problem eliminated my idea of pipe pile from the inside too.

Mike McCann
McCann Engineering