As a continuation of our discussion on Field Investigation Tips, we’ll take a quick look at another (incredibly important) concern when conducting a (subsurface) field investigation: buried utilities.  Much like our previous topic (Field Investigation Tips Vol. 1: Working in the Rain), there are inherent difficulties when required to work in “congested” areas where you see mark-out paint all over your investigation area.  But don’t be fooled…buried utilities have a sneaky way of turning up in less obvious areas too. So, in the spirit of keeping things relatively simple, listed below are some key tips (some obvious / some less obvious) that could be used by most practitioners (environmental, geologic, engineering, etc.) to hopefully help avoid common pitfalls when installing borings, wells, test pits, etc.  As always, Safety is paramount for any subsurface investigation.

 Obvious Tips:

·   Tip #1: Get a utility mark-out.  It’s the law in most states.  Don’t rush in.  

·  Tip #2: Hire a private utility mark-out service.  This is an “easy” solution for private properties and highly recommended where you anticipate having subsurface obstructions and/or utilities. GPR services are often worth the extra expense.

·   Tip #3: Schedule to have your locations pre-cleared to a specified depth using a “soft-dig” approach.  Some clients and facilities (e.g. refineries) may require this already, so use this option if warranted.

·   Tip #4: Be prepared to ask your client, site operators, or any other individual if they have specific knowledge of buried utilities, and/or if they have as-builts or other site figures they could supply.  Also have them physically point out where the utility conflicts may be, prior to commencing work.  

·   Tip #5: Make sure your firm is under contract before conducting any intrusive work, and the contract language addresses subsurface utilities.  Also…make sure you’re insured. Really. Get insurance.

·    Tip #6: Maintain a safe distance from all utility mark-outs…generally this means >3ft.  

Less-Obvious Tips:

·  Tip #1: Utility mark-outs may fade or get washed away.  If warranted, be prepared to postpone a project until a new mark-out can be completed.  Also get a new mark-out if your ticket has expired!

·  Tip #2: Be wary of pipe bedding or other common backfill materials when advancing a test pit, borehole, etc.  If encountered, chances are you may on top of, or near, a subsurface utility.  Be prepared to off-set if your location if needed. 

·   Tip #3: After obtaining utility clearance (and not opting to soft dig), pay attention to your drill or geoprobe rig (or excavator) as it approaches the infamous 4ft depth.  This is a common depth where utilities may be located, as it’s generally below the frost line in the Eastern U.S. If the equipment is having difficulty advancing, shaking, or lifting, and boulders, concrete, deleterious material (for example) were not expected, take time to re-evaluate your location…don’t force it. You may be on a utility.  

·   Tip #4: Don’t solely rely on old plans.  They have a tendency of being wrong.   

·   Tip #5: Trust your gut!  If you think something is off, whether it’s a mark-out or plan specifications, don’t hesitate to stop work and get the answers you need and “re-assurances” before commencing work.  People’s lives could be at risk, so avoid making hasty decisions, and don’t let a project schedule or budget dictate your level of safety.  

Stay tuned for future Field Investigation Tips in the upcoming weeks…as there are plenty of lessons to be learned and shared, which could ultimately make our jobs easier and safer! We hope that you find these posts informative, and relatively useful, and your feedback is always welcome. For further information please don't hesitate to contact us at tfrancis@cardinallsrp.com  or www.cardinalLSRP.com