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PRS Erosion Matrix Score Assessment Date Structure Mesa Top Bench Canyon Floor Channel Topography Explanation Ground Explanation Slope Explanation Runoff Evidence Channelized Channel Description Runoff Wetland Runoff Other Terminus Explanation Runoff Explanation Structure Run-On Structure Explanation NPDES Run-On NPDES Explanation Natural Run-On Natural Run-On Explanation ESH-18 Representative BMP Prescription BMP Description Not BMPs Sediment Comments
40-001(b) 14.0 7/31/1997   YES NO NO NO Inactive septic. Grasses & pine needles.   NO NO Subsurface - no watercourse issues.         NO   NO   NO   S. Veenis     NO  
40-001(c) 3.6 8/7/1997   NO NO NO NO Active septic system. Thick vegetative cover.   NO NO           NO   NO   NO   R. Reynolds     NO  
40-002(b) 15.3 3/19/1998 40-15 YES NO NO NO On bench midway on canyon side (see 3rd page drawing).  A container used to store shot wastes staged at PRS 40-006(a).  Bare ground, no vegetation around chamber pad. Firing pad relatively flat. NO NO The storage container itself, is totally enclosed.  The runoff potential is for the firing pad, PRS 40-006(a).       None for storage container. NO None for storage container. NO   NO None for storage container. R. Reynolds Remove container when full with assurance that overfilling will not occur.   NO See attached drawing.  According to the AP 4.5(a) by R. Romero completed 1/7/98, PRSs 40-006(a) and 40-002(b) share the same site.  Since 40-002(b) is a container storage vessel, no erosion potential exists.  The erosion potential for this site is reflected on the Part B form for 40-006(a).  The visible debris observed will also be addressed at PRS 40-006(a).
40-003(a) 46.3 12/18/2000 40-15 YES NO NO NO Former scrap detonation area located on eastern boundary of TA-40. Mixed grasses and rocky terrain throughout site.  Area mostly void of vegetation due to the activities that were performed here. Detonation area is flat, gently sloping towards the south. YES NO Evidence of sheetflow runoff towards the mesa edge.     Runoff discharges directly to Pajarito Canyon.  No channelization was observed, so the runoff is mostly sheetflow. None observed. NO No structural impacts. NO No operational impacts. YES Run-on from hillside above site. Veenis, Steve Site should be revegetated to improve final stabilization success.   NO Revegetation needed.
40-003(b) 46.3 12/18/2000 40-15 YES NO NO NO Former scrap detonation area located on eastern boundary of TA-40. Mixed grasses and rocky terrain throughout site.  Area mostly void of vegetation due to the activities that were performed here. Detonation area is flat, gently sloping towards the south. YES NO Evidence of sheetflow runoff towards the mesa edge.     Runoff discharges directly to Pajarito Canyon.  No channelization was observed, so the runoff is mostly sheetflow. None observed. NO No structural impacts. NO No operational impacts. YES Run-on from hillside above site. Veenis, Steve Site should be revegetated to improve final stabilization success.   NO Revegetation needed.
40-005 39.8 8/7/1997   YES NO NO NO   b) Outfall site

c) Active HE sump - discharge unknown EPA-050A-154 selected 12-95 TA40-41
Asphalt surrounding sump, outfall discharged to grassy hillside. YES YES Combination of parking lot run-off and sheet flow.         YES Run-off onto site but around protected, covered sump.

Parking lot and roof drain discharge SW onto old outfall site.
NO   YES Culvert and swale direct SW onto PRS (outfall site). R. Reynolds     NO Grassy slope and natural vegetation is sufficient.
40-006(a) 56.2 6/22/2000 40-15 NO YES NO NO Active firing site near 40-15. a)  Bare ground, no vegetation around firing pad.

b)  Canyon side leading to water course (included in PRS).
a)  Firing pad

c)  Canyon side.
YES YES Area bermed for runoff from firing pad.  The slope collects sheetflow runoff which discharges into canyon.     Active firing site is more or less contained.  Shot debris observed on slope with sheet flow termination into Pajarito Canyon. Sheet flow erosion inferred from canyon slope. NO Run-on bermed from slope. NO No NO No Veenis, Steve Debris clean-up needed.   NO Original assessment completed on 8/7/97 with a score of 83.  Apparently the wrong site was assessed, and a new evaluation was completed.
40-006(b) 62.0 6/22/2000 40-8 YES NO NO NO Active firing pad located behind building 40-8. Mostly barren with some mixed shrubs on slope below the site. Pad area flat, slope below the pad steep into Pajarito Canyon. YES NO Runoff evidence on slope.     Runoff terminates into Pajarito Canyon below site. No erosional features were observed. YES Run-on from building roof drains flows across parking lot and onto the site. YES Active operations from firing site activities. NO None. Veenis, Steve   Straw wattles were installed on the steep portion of the slope to reduce sediment migration potential.  Wattles were also installed on the mesa's edge to divert run-on. NO The site was moderately impacted by the Cerro Grande Fire.  The BMPs were installed after the fire.  Firing site debris is scattered across slope.
40-006(c) 62.0 6/22/2000 40-5 YES NO NO NO Active firing pad located behind building 40-5. Mostly barren with some mixed shrubs on slope below the site. Pad area flat, slope below the pad steep into Pajarito Canyon. YES NO Runoff evidence on slope.     Runoff terminates into Pajarito Canyon below site. No erosional features were observed. YES Run-on from building roof drains flows across parking lot and onto the site. YES Active operations from firing site activities. NO None. Veenis, Steve   Straw wattles were installed on the steep portion of the slope to reduce sediment migration potential.  Wattles were also installed on the mesa's edge to divert run-on. NO The site was moderately impacted by the Cerro Grande Fire.  The BMPs were installed after the fire.  Firing site debris is scattered across slope.
40-009 54.5 3/4/1998 40-9 NO YES NO NO Disposal area over mesa edge. Mostly crushed tuff with sparse grass and shrubs on slope.  Good coverage of grass and pine needles on bench. Steep slope to bench, then cliff into canyon. YES YES Sheet flow from slope into natural drainages below.  Channels on east and west boundaries of PRS.     Sheet flow from steep slope onto bench.  Channels on east and west boundary discharge over edge into canyon. None observed on most of site.  Sheet flow erosion is inferred due to steepness of slope and exposed materials. YES Drainage channel west of 40-9 directs flow onto site, then dissipates on slope.  Eastern boundary has channel which discharges and onto site and creates gully. NO (04A101 inactive) NO None. S. Veenis Run-on diversion on top of mesa would practically stop any future erosion.  Remove visible debris.   NO Cans, glass, concrete, asphalt, tarps, miscellaneous debris.  Wrong site intially assessed.
40-010 40.2 6/22/2000   YES YES NO NO Landfill located on mesa edge with much of the debris off the edge and onto the slope. Little or no vegetative cover. Slope below mesa edge steep towards canyon bottom. YES NO Runoff channelized around the western end of site.  Sheet flow from a majority of the site. Bench below site   Runoff appears to terminate below site on bench setting. Sheet flow erosion inferred from site setting and runoff evidence. NO None NO None NO None. Veenis, Steve Sediment controls below site.   NO Visble debris found throughout the site.