CS18A - Concurrent Session 18A: Updates to USACE Drilling Guidance ER 1110-1-1807

There are many examples of poor investigation techniques causing damage to dams and levees. Care must be taken when approaching this type of work to minimize the risk of hydraulic fracture of this critical infrastructure. USACE ER 1110-1-1807 is a critical document for planning safe investigations near dams and levees. This ER went through a major overhaul and was most recently published in 2014, but many lessons learned since then have resulted in another update this year.

Some of the most critical updates include:

• Establishes a minimum FS for hydraulic fracture of 1.3. Previous version was silent.
• Requires documentation of two methods to calculate that FS. There are several potential equations that can be used, but none are ideal. Previous version was silent on method and did not require calculation submissions.
• Applied to not just embankments, but all dams and levees.
• Changed Drilling Program Plan to Drilling and Invasive Program Plan since this ER also applies to test pits and other non-drilling activities.
• Added a license requirement for preparer of DIPPs (not previously required).
• Clarified experience requirements for drillers.
• Clarified the construction exemption – for drilling that has undergone ATR/SAR.
• Clearly stated that approval of a DPP (now DIPP) is a federal action that triggers NEPA.

This presentation will summarize the changes and rationale behind them.