Coal Mine Impoundment Inspection Training

1. Coal Mine Impoundment Inspection Training Conducted By: Tri-State Safety Training Services Uniontown, PA 15401 724-439-2601

2. VISUAL INSPECTION OF EMBANKMENT DAMS WHAT YOU NEED TO KNOW TO INSPECT AN EMBANKMENT DAM, AND FILL OUT A REPORT OF YOUR INSPECTION

3. WHAT WE’LL COVER: • BASIC DEFINITIONS • FEATURES OF A DAM; CONTROL FEATURES • DEFICIENCIES - POSSIBLE PROBLEMS • SEEPAGE, MOVEMENT, BLOCKAGE OF CONTROL FEATURES, EROSION, FIRE • INSPECTION ROUTE AND REPORT • COMMON INSTRUMENTATION • PIEZOMETERS, WEIRS, STAFF GUAGES, MONUMENTS • REGULATIONS

4. BASIC DEFINITIONS • DEFINITION OF AN EMBANKMENT DAM • CONFIGURATIONS • FEATURES OF AN EMBANKMENT DAM: • 6 MAIN FEATURES: CREST, SLOPE, BENCH, TOE ABUTMENT, GROIN • CONTROL FEATURES: • 4 COMMON CONTROL FEATURES: SPILLWAYS, DECANTS, CUTOFFS, DRAINS • DEFINITION OF LEFT SIDE / RIGHT SIDE

5. EMBANKMENT DAMS ARE CONSTRUCTED OF SOIL MATERIALS - INCLUDING MINE WASTE & REFUSE

6. DAMS ARE USED FOR FRESH WATER SUPPLY, OR FOR REFUSE DISPOSAL IN GENERAL, INSPECTION ACTIVITIES ARE THE SAME FOR EITHER USE, BUT THERE ARE SOME DIFFERENCES, THAT WILL BE ADDRESSED IN LATER SECTIONS

7. OTHER TYPES OF DAMS ARE UNLIKLY TO BE FOUND ON MINING SITES • CONCRETE ARCH • GRAVITY • MASONARY

8. CROSS VALLEY SIDE HILL DIKED INCISED THESE CONFIGURATIONS ARE BASED ON THE SHAPE OF THE EMBANKMENT WITH RESPECT TO THE SURROUNDING TOPOGRAPHY COMMON CONFIGURATIONS FOR EMBANKMENT DAMS:

9. CROSS VALLEY THE EMBANKMENT CROSSES AND BLOCKS A VALLEY

10. SIDE HILL A SIDE HILL IMPOUNDMENT LIES ALONG THE SIDE OF A SLOPE, OR HILL, AND DOES NOT CROSS A VALLEY BOTTOM

11. DIKED AN ENCLOSED DIKE BUILT ABOVE RELATIVELY LEVEL GROUND

12. INCISED EXCAVATED BELOW ORIGINAL GROUND LEVEL

13. COMMON FEATURES OF EMBANKMENT DAMS • CREST • SLOPE • BENCH • TOE • ABUTMENT • GROIN

14. “CONTROL FEATURES” ARE STRUCTURES DESIGNED TO CONTROL SEEPING OR FLOWING WATER. • SPILLWAY • DECANT • DRAIN • KEYWAY (CUTOFF)

15. SPILLWAYS ARE STRUCTURES DESIGNED TO HANDLE FLOOD-FLOWS

16. DECANTS ARE STRUCTURES DESIGNED TO MAINTAIN NORMAL POOL ELEVATION

17. DRAINS ARE DESIGNED TO SAFELY COLLECT & CARRY SEEPAGE OUT OF THE DAM

18. KEYWAYS ARE DESIGNED TO REDUCE SEEPAGE RATE THROUGH OR UNDER DAM

19. LEFT SIDE / RIGHT SIDE OF A DAM IS DETERMINED BY VIEWING THE DAM ORIENTED LOOKING DOWNSTREAM

20. DEFICIENCIES “DEFICIENCIES,” OR “SIGNS OF DISTRESS,” ARE INDICATORS THAT A POTENTIAL PROBLEM IS DEVELOPING WITH THE DAM

21. UNCONTROLLED SEEPAGE DISPLACEMENT OF EMBANKMENT BLOCKAGE/DAMAGE TO CONTROL FEATURES EROSION FIRE (COAL REFUSE SITES) 5 CATEGORIES OF DEFICIENCIES

22. TWO TYPES OF SEEPAGE: • CONTROLLED: SEEPAGE THAT IS SAFELY COLLECTED & DISCHARGED OUT DRAIN • UNCONTROLLED: SEEPAGE THAT IS NOT SAFELY COLLECTED & DISCHARGED OUT DRAIN • BY DEFINITION, ONLY UNCONTROLLED SEEPAGE IS A DEFICIENCY • NOT ALL SEEPAGE COMING OUT A DRAIN IS “CONTROLLED”

23. ALL DAMS LEAK

24. PLACES TO CHECK FOR SEEPAGE: • DRAIN OUTLETS • TOE AREA • AROUND PIPES THAT COME THROUGH DAM • GROIN DITCHES • SLOPE BELOW POOL • HILLSIDE DOWNHILL OF GROIN • VALLEY BOTTOM BELOW TOE • ADJACIENT VALLEY • PERIMETER OF POOL

25. DRAIN OUTLETS

26. TOE AREA

27. AROUND PIPES THAT COME THROUGH DAM

28. GROIN AREA

29. SLOPE BELOW POOL

30. VALLEY BOTTOM GOOD PLACE TO LOOK FOR “BOILS”

31. PERIMETER OF POOL, ESPECIALLY UPSTREAM GROIN

32. EVIDENCE OF SEEPAGE • FLOWING WATER (DUH) • DARKER SPOTS (MOIST) - LIGHTER SPOTS (EVAPORITES) • IRON STAINS • LUSH VEGITATION (MOISTURE) • DYING VEGITATION (MOISTURE CARRIES SALTS OR ACID) • WATER LOVING VEGITATION (CATTAILS) • WINTER - ICE OR MELTING SNOW

33. EVIDENCE OF SEEPAGE

34. RECORDING SEEPAGE IN REPORT • LOCATION • DESCRIBE WITH RESPECT TO SOME FEATURE • MARK ON DRAWING, OR XEROX OF PLAN VIEW • QUANTITY • USUALLY EYE-BALLED IN GPM • PRECISE MEASUREMENT MUCH BETTER • QUALITY • IS SEEPAGE CLEAR, OR IS IT COLORED WITH SOIL PARTICLES (TAN, BROWN, GRAY, BLACK, MILKY, ETC.

35. CRITICAL SEEPAGE OBSERVATIONS - THINGS YOU DON’T WANT TO SEE • YOU DON’T WANT TO SEE: • LARGE SEEPS • SEEPS THAT INCREASE SIGNIFICANTLY IN SIZE • SEEPS THAT ARE MILKY OR COLORED BY SOIL PARTICLES

36. DISPLACEMENT OF EMBANKMENT ANY EVIDENCE THAT THE EMBANKMENT HAS MOVED, EITHER AS A WHOLE, OR AS ANY PART WITH RESPECT TO ANOTHER PART

37. EVIDENCE OF DISPLACEMENT OF EMBANKMENT • CRACKS • BULGES • SCARPS • DEPRESSIONS • MISALIGNMENTS • DISPLACED TREES • SINKHOLES

38. DISPLACEMENT LEADING TO CRACKING,BULGE, & SCARP • SLIGHT INITIAL MOVEMENT MAY YIELD SMALL CRACKS ON THE CREST, OR ON EITHER FACE. • CONTINUED MOVEMENT MAY YIELD LARGE VERTICAL DISPLACEMENT (SCARPING) WITH CORRESPONDING BULGES DOWNHILL

39. SMALL CRACKS MAY PRECEDE SLIPPING AND SCARPING

40. ROTATIONAL, AND WEDGE FAILURES

41. THREE TYPES OF CRACKING • LONGITUDINAL • LENGTH OF CRACK IS ORIENTED WITH THE LENGTH OF THE CREST • TRANSVERSE • LENGTH OF CRACK IS ORIENTED PERPENDICULAR TO LENGTH OF CREST • POLYGONAL • HONEYCOMB, OR POLYGONAL ORIENTATION OF CRACKS

42. DEPRESSIONS & SINKHOLES

43. SINKHOLE FORMATION

44. DISPLACED TREES

45. RECORDING DISPLACEMENT • LOCATION • DISCRIBE LOCATION WITH RESPECT TO DAM FEATURES • MARK ON DRAWING OR PLAN VIEW • TYPE • CRACK, BULGE, DEPRESSION, ETC. • SIZE • LENGTH, WIDTH, DEPTH, ETC. • ORIENTATION • TRANSVERSE, LONGITUDINAL, ETC.

46. BLOCKAGE/DAMAGE OF CONTROL FEATURES • BLOCKAGE OF, OR DAMAGE TO: • SPILLWAYS • DECANTS • DRAINS

47. BLOCKAGE OF/DAMAGE TO SPILLWAYS • OPEN CHANNEL: • MATERIAL SLOUGHED INTO SPILLWAY • MATERIAL ABOUT TO FALL INTO SPILLWAY • MATERIAL INTENTIONALLY PLACED IN SPILLWAY • EROISION DAMAGE TO SPILLWAY • INSUFFICIENT EROSION PROTECTION • PIPE: • DAMAGE TO PIPE • DETERIORATION OF PIPE • BLOCKAGE OF PIPE • POTENTIAL BLOCKAGE OF PIPE

48. MATERIAL SLOUGHED OR PLACED IN SPILLWAY

49. INSUFFICIENT EROSION PROTECTION OF SPILLWAY

50. BLOCKAGE OF/DAMAGE TO DECANTS: • TRASH RACKS BLOCKED WITH DEBRIS • TRASH RACKS NOT IN PLACE, OR SUBJECT TO DISLODGEMENT • SLOUGHAGE, OR POTENTIAL SLOUGHAGE OF MATERIAL ONTO DECANT INLET • MOVEMENT OF DECANT FOUNDATION • FLOTATION OF DECANT INLET