Steven Hubble, Environmental Programs Manager Department of Public Works October 7, 2011

Introduction Field/Project Experience Soils Policy Recommendations Conclusion

Naturally occurring soils or sediments formed under waterlogged conditions Contain iron sulfite materials (pyrite) Are benign while underground Become acidic when excavated and left exposed on the surface to oxygen

Small lot (1/4 acre lots) residential subdivision Large lot (1 acre lots) residential subdivision Transportation (Roadway-Widening) Project

Located near Falmouth, VA 147 lot cluster residential lot subdivision Avg. lot size 8,000-10,000 sq. feet (sod required for lots) 1 developer (local), 2 builders (1 regional, 1 national) Construction begins late 2005/early 2006 Acid Sulfate and Soil Stabilization problems noted in 2009 VT staff (Lee Daniels) contacted for assistance Soil testing conducted and remediation plans developed by developer and builders through geotechnical/engineering consulting firm Significant remediation activities completed in 2009/2010 Remediation activities continue/complete Soil pH readings range from normal to +/- 2.5 pH

Continue to monitor site for recurring problem areas Mitigate remaining areas as necessary Complete infrastructure construction and address outstanding completion items Hold securities until issues are resolved

Near Falmouth, VA 63 lots (minimum of 1 acre) Developer absent due to bankruptcy County utilizing security funds to complete infrastructure improvements Acid Soils encountered during completion of neighborhood stormwater management pond Acid soils relocated to other parts of the neighborhood

Widening of a roadway from 2 to 4 lanes Road improvements proffered and constructed by a developer for VDOT Acid Soils prevalent in the area (Quantico Slate) and unearthed during initial road construction (late 80’s/early 90’s) Large underground electrical transmission line is located in the area

Established by County Building Official with enabling authority from the Virginia USBC (Building Code) Soil evaluation required for acid sulfate soils and other soil issues (shrink swell, compacted fill) If acid soils are suspected, testing is required If the test does not register between pH of 5.5 and 7.5, then mitigation to improve soil pH is required

Use Statewide soils data merged with locality specific data to identify potential risk locations Attempt to identify problem soils prior to excavation If acid soils excavated during cut, place those soils in a deep fill area where they will not be exposed to oxygen Educate inspectors/staff on acid soils to help them identify in the field if exposed Consider regulations that address acid soils at the development plan or building permit stage Ask for help if you encounter acid soil problems

Training Class on this topic hosted by Virginia Association of Professional Soils Scientists November 3 and 4-Fredericksburg, VA _S_Final_Program.pdf _S_Final_Program.pdf

Steven Hubble, Environmental Programs Manager Department of Public Works P.O. Box 339 Stafford, VA