Underground utilities

[ssn61]

I am not sure if this is the right forum to ask this question but anyhow, this is my question. In the horizontal (building) architectural/MEP engineering world who is responsible for identifying and relocating underground utilities that fall under the footprint of a new building. For example, chilled water piping, electrical cables, fire sprinkler pipes, sewer lines and drains, natural gas lines, etc. I am thinking the surveyor company identifies them and civil engineer shows them on his drawings as to be relocated.

 

[lukaiENG]

I've recently had a project just like this. We are building a new electrical switchgear building directly over existing fuel lines and associated conduits.
in this case we did not need a civil survey as it was quite apparent where the lines ran (we could see both ends).
The relocation was documented on the mechanical and electrical drawings for the underground respective services. I would think you would want to do it this way as you would want to be in control of the connection details, I would anyway...

 

[ssn61]

lukaiENG, I understand what you are saying on specific projects, but my question is regarding general situation. It is a good idea to have a civil engineer on a project especially if it is a ground up building. I Know MEP engineers have certain responsibilities and so do the civil engineers on the project. I am trying to figure out the extent of responsibilities and the distinguishing line of who puts what on the drawings when it comes to underground utilities. I don't want to overstep my authority when it comes to what I should put on my drawings as a MEP engineer.
For example, I know when we put a hot water boiler that is over 400 mbh in an exiting building mechanical room we need to have a 1 hour fire rated wall per IBC. Should I as the mechanical engineer of record define and design the 1 hour wall? Although I might know how, but I think that is an architect's job. I hope it makes sense.

 

[lukaiENG]

that shoulds fine in a perfect world, but most civil engineers are going to be used dealing with details of chilled water piping and sprinkler piping in the same way that you could rely on them to cover the scope of drainage and water mains. It's just not in their wheelhouse.
I would suggest the best way would be for the civil drawing to show all scope with "refer MEP drawings for details" notes for items they don't normally address. A quick discussion with a friendly civil consultant will quickly give you an idea what they are comfortable with detailing.

 

[dbill74]

Generally speaking, any utility service within 5' of the footprint of the building falls under the responsibility of the MEP engineers; beyond the 5' line is the civil engineer's domain. However, that demarcation is extended to encompass major mechanical equipment such as chillers, cooling towers, etc. Regarding your fire wall; the wall is an architectural element and is the responsibility of the architect to specify and detail.

In a case where a new building is being constructed where utilities such as storm or sanitary lines exist, the civil engineer is responsible for moving/coordinating those existing utilities as part of the site work in preparation for the new building. Then all new utilities within 5' of the footprint are the MEP's.

The design of a building is a team effort and as an MEP engineer you are one part of that team. Being in a position where my job entails review of design documents, I cannot tell you how many times I have seen plans where the engineers are obviously not communicating with the architect except to exchange drawing files. It's not that hard to call or email other team members to coordinate things, I know, I've been on that side of the design process before.

I once had a colleague tell me she considers a good bob one where they get plenty of RFIs. I disagree with that mentality, a good job is one where you get few if any RFIs. Why do I feel this way? It is less work for me to do and there are fewer opportunities for a contractor to get change orders which can be costly.

 

[ssn61]

Thank you so much dbill74 for the wonderful answer. These are the type of answers I would like to see from individuals such as yourself with real world experience , which unfortunately are few and far between. This particular project I am working on is on a Hospital campus and fills up an empty space about 1500 sq.ft. between an office area of the main hospital and a metal storage building about 2000 sq.ft, which is located about 50 feet away. The new building is going to be used for IT support of some sort. Apparently the subsurface survey shows that there are some underground utilities- electrical, Natural gas,SS, and SD, all about 3 to 5 feet deep where the foot print of the new building is going to be. My question is, does the 5 feet rule still apply? Is this is part of civil, architect, (and utility company) responsibility to put on their drawings?
By the way, being an engineer, I like to see concrete answers, well...most of the time of course. So I always look for codes, standards, and such. Is there any written standards or rules regarding issues like this anywhere?
dbill74, thanks again for the reply, I truly appreciate it.

 

[dbill74]

Unfortunately I don't know where the 5' rule came from, its something I've been working with since I started in the field.

I would expect relocation of these utilities so that they are not under the new building and for the civil engineer to handle their relocation. Then any new utilities (electrical, SS, SD, etc.) within 5' of the new building would be the responsibility of the MEP engineers, even if the new utilities are below the new building slab. In the event the existing utilities are not relocated and the new building is erected on top of them, it would be smart of you to mark their locations 'for coordination only'.

Codes and standards do not address all scenarios and situations you will see in building construction, nor do they tell you how to do build a building. What they do is provide a set minimum requirements of performance and guidance. For example, Int'l Mechanical code requires 50 CFM of exhaust per toilet/urinal in a bathroom, smart design would be to use closer to 75 CFM per fixture. This is because it is impossible to 50 CFM per fixture in a bathroom and keep it throughout the life of the building. How much more than the required 50 CFM do you do? That's a judgment call you need to make as the engineer and depends on more things than I can list here.

To answer your question, it depends. In your case on what you agreed to be responsible for when taking on the job. For that you will need to review and coordinate with your client. What I described above is I would be my default understanding of responsibilities, this doesn't mean this is going to be the case for all your projects all the time. Your best bet to get the right answer for your hospital job is to ask whomever negotiated the contract you are working under and ask him.

 

[cry22]

In general, chilled water campus distribution is handled by the Mechanical engineer, not just 5' outside the building like the plumbing usually does.

Chilled water requires proper piping expansion, cathodic protection, valve access with manholes, elevation coordination (CHW does not have right of way underground, it is under pressure), drainage points, specifications (perma-pipe for direct burried pipes) etc.

The civil will not detail the CHW network requirements. He will show elevation and no more.