On the way to dinner Sunday evening I noticed construction equipment on one of my projects that's not due to break ground until mid-March. No one has requested any control or asked for any staking so I assumed the owner was getting a head start on clearing and erosion control. I passed the site again today and realized that they aren't just doing prep work, they're installing the new sanitary sewer line that angles through the site.
I stopped in and saw a city worker supervising the installation of the manhole that straddles an existing line. When I inquired who had performed that staking for the work he said "Well, we GPS'ed the upper manhole and this one right here we called the engineer and got him to give us a distance from the curb line".
My survey has coordinates based on the City's local coordinate system that dates to the 50's. This system is known to have inconsistencies if you span a very large area and I doubt that it would be possible to tie in with RTK in a way that would allow you to work accurately city wide. I know that they didn't tie to any of my published control because the site is heavily wooded. I can't wait to get a chance to check their work.....I'm betting the error will be measured in feet.:-(
Stephen,
Let us know how it turns out. Sometimes people do not have a clue what they are doing.
On another note, it was good speaking with you last week. Hope all is well.
Take care,
Jimmy
I was once asked to stake an addition to a major building addition at a church camp along with some other staking. The architects map supplied coordinates. I was going to do it for nothing since our church also used that camp. I asked how the coordinates on the various building corners were derived since I didn't think another surveyor or engineer was involved. With a straight face the camp administrator said the architect used a handheld GPS receiver and obtained them to save the camp costs. I kid you not! I declined to get involved at that point.
hopefully everything flows the right way...
you can always get paid extra for having to make field adjustments so the buildings meet the offsets to the existing sewer...
Jerry,
That's why when I was starting in business I stayed away from church projects. Especially if the prime was an arch. Too much of a risk not to get paid and then have the building committee never make up their minds on what they wanted.
I hope the arch used mapping grade gps....you know that's much better than what we use...:)
I'm not worried about the grade, I trust that they can work upstream from the existing line and make it flow. Fortunately it was designed well clear of all buildings but may interfere with a proposed storm drain or other proposed underground utilities if they're off very much. I'll post a diagram of the designed vs. built locations when I get a chance to check their work.
I recall working on a subdivision back when I was in the private. The contractor "staked" all of the sewer himself to save money. One manhole wound up in the sidewalk at a 90 degree bend in the street. The County let him get away with it so I guess it's OK.
You can bet if we had staked it then the contractor would've made sure that the inspector made him move the manhole and charged the client a huge extra which would've gotten backcharged onto us. I've seen happen more than once. It's a cut throat business.
At one company I worked for a number of years ago, I remember one large job in particular (for this particular issue): the company I worked for staked the underground utilities. The developer decided to do the road of one section himself, and the grade wound up about 3 feet too low. Of course, there was all sorts of mess going on with our company scrambling to cover their butts and proving we had nothing to do with the screw up. I do not remember how that was resolved.
