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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 35-002 3.6 7/30/1997 YES NO NO NO NO NO NO NO NO D. Mays NO 35-003(a) 27.6 5/20/1998 35-2 YES NO NO NO Location of former Building 35-7, removed 1996. Underground tank associated with the phase separator pit. Former building location leveled (35-7) and stabilized with base course. The PRS is totally covered with asphalt. Slight slope to NE onto base course parking area. YES YES Sheet flow onto parking area & adjacent storm water catch basin which discharges into Ten-Site Canyon to the south. Small portion of site drains into the local storm water runoff system and discharges into Ten Site Canyon. Most of site sheet flows onto base course parking area east of site. None observed at site. NO Concrete curb upslope diverts run-on. NO All operations ceased, all facilities removed. NO D. Mays Asphalt cover, concrete curb for run-on control NO Site originally assessed on 9/24/97. Site re-visited based on a request from G. Lopez-Escobedo who thought the wrong site had originally been assessed. The site was originally grouped with some other down slope PRSs. Original date to NMED: 12/18/97 date to ESH-18 10/1/97 35-003(b) 27.6 5/20/1998 35-2 YES NO NO NO Location of former Building 35-7, removed 1996. Underground tank associated with the phase separator pit. Former building location leveled (35-7) and stabilized with base course. The PRS is totally covered with asphalt. Slight slope to NE onto base course parking area. YES YES Sheet flow onto parking area & adjacent storm water catch basin which discharges into Ten-Site Canyon to the south. Small portion of site drains into the local storm water runoff system and discharges into Ten Site Canyon. Most of site sheet flows onto base course parking area east of site. None observed at site. NO Concrete curb upslope diverts run-on. NO All operations ceased, all facilities removed. NO D. Mays Asphalt cover, concrete curb for run-on control NO Site originally assessed on 9/24/97. Site re-visited based on a request from G. Lopez-Escobedo who thought the wrong site had originally been assessed. The site was originally grouped with some other down slope PRSs. Original date to NMED: 12/18/97 date to ESH-18 10/1/97 35-003(c) 27.6 5/20/1998 35-2 YES NO NO NO Location of former Building 35-7, removed 1996. Underground tank associated with the phase separator pit. Former building location leveled (35-7) and stabilized with base course. The PRS is totally covered with asphalt. Slight slope to NE onto base course parking area. YES YES Sheet flow onto parking area & adjacent storm water catch basin which discharges into Ten-Site Canyon to the south. Small portion of site drains into the local storm water runoff system and discharges into Ten Site Canyon. Most of site sheet flows onto base course parking area east of site. None observed at site. NO Concrete curb upslope diverts run-on. NO All operations ceased, all facilities removed. NO D. Mays Asphalt cover, concrete curb for run-on control NO Site originally assessed on 9/24/97. Site re-visited based on a request from G. Lopez-Escobedo who thought the wrong site had originally been assessed. The site was originally grouped with some other down slope PRSs. Original date to NMED: 12/18/97 date to ESH-18 10/1/97 35-003(d) 59.0 8/6/1997 35-7 NO YES NO NO Down slope from former Building 35-7, site of former WWTF. Sparse vegetation throughout most of site. Flat on top steepens toward head of Pratt Canyon. YES YES Earth berm stabilized with jute mat, diverts run-off to riprap-lined channel leading to Pratt Canyon, tributary to Ten Site Canyon. Discharges directly into head of canyon. Rills have formed on lower side of berm and below site above canyon. YES Former building upstream Building 35-7. NO NO D. Mays More revegetation effort is needed BMP in place: Earth berm to divert run-off to riprap-lined channel. Area backfilled and reseeded 1996. Additional work completed in 12/98 included fixing breached berm, provided extra riprap and compaction of soils at site. NO Rill/Gully erosion is beginning to form at interim action site. 35-003(e) 32.5 8/6/1997 35-7 YES NO NO NO Removed Building 35-7. Covered with gravel for old building, asphalt around old building, and soil at perimeter. YES NO Ten Site Berm down slope of site detains run-off which then trickles down slope towards canyon. YES Asphalt parking up slope. NO NO D. Mays NO Fix hole in earth berm. Remove straw bales which have mostly decayed. Pick up trash at NE corner of PRS inside berms. 35-003(f) 32.5 8/6/1997 35-7 YES NO NO NO Removed Building 35-7. Covered with gravel for old building, asphalt around old building, and soil at perimeter. YES NO Ten Site Berm down slope of site detains run-off which then trickles down slope towards canyon. YES Asphalt parking up slope. NO NO D. Mays NO Fix hole in earth berm. Remove straw bales which have mostly decayed. Pick up trash at NE corner of PRS inside berms. 35-003(g) 32.5 8/6/1997 35-7 YES NO NO NO Removed Building 35-7. Covered with gravel for old building, asphalt around old building, and soil at perimeter. YES NO Ten Site Berm down slope of site detains run-off which then trickles down slope towards canyon. YES Asphalt parking up slope. NO NO D. Mays NO Fix hole in earth berm. Remove straw bales which have mostly decayed. Pick up trash at NE corner of PRS inside berms. 35-003(j) 34.6 8/20/1997 YES NO NO NO Parking lot/driveway between Buildings 35-29 and 35-2. Asphalt. Flat. YES NO Sheet flow off asphalt. YES PRS is currently under parking lot. NO NO D. Mays NO 35-003(k) 34.6 8/20/1997 YES NO NO NO Parking lot/driveway between Buildings 35-29 and 35-2. Asphalt. Flat. YES NO Sheet flow off asphalt. YES PRS is currently under parking lot. NO NO D. Mays NO 35-003(l) 59.0 8/6/1997 35-7 NO YES NO NO Down slope from former Building 35-7. YES YES Earth berm stabilized with jute mat, diverts run-off to riprap-lined channel leading to Pratt Canyon, tributary to Ten Site Canyon. YES Former building upstream Building 35-7. NO NO D. Mays More revegetation effort is needed. BMP in place: Earth berm to divert run-off to riprap-lined channel. Area backfilled and reseeded 1996. Additional work completed in 12/98 included fixing breached berm, provided extra riprap and compaction of soils at site. NO Rill/gully erosion is beginning to form at interim action site. 35-003(m) 32.5 8/6/1997 35-7 YES NO NO NO Removed Building 35-7. Covered with gravel for old building, asphalt around old building, and soil at perimeter. YES NO Ten Site Berm down slope of site detains run-off which then trickles down slope towards canyon. YES Asphalt parking up slope. NO NO D. Mays NO Fix hole in earth berm. Remove straw bales which have mostly decayed. Pick up trash at NE corner of PRS inside berms. 35-003(n) 27.6 5/20/1998 35-2 YES NO NO NO Location of former Building 35-7, removed 1996. Underground tank associated with the phase separator pit. Former building location leveled (35-7) and stabilized with base course. The PRS is totally covered with asphalt. Slight slope to NE onto base course parking area. YES YES Sheet flow onto parking area & adjacent storm water catch basin which discharges into Ten-Site Canyon to the south. Small portion of site drains into the local storm water runoff system and discharges into Ten Site Canyon. Most of site sheet flows onto base course parking area east of site. None observed at site. NO Concrete curb upslope diverts run-on. NO All operations ceased, all facilities removed. NO D. Mays Asphalt cover, concrete curb for run-on control NO Site originally assessed on 9/24/97. Site re-visited based on a request from G. Lopez-Escobedo who thought the wrong site had originally been assessed. The site was originally grouped with some other down slope PRSs. Original date to NMED: 12/18/97 date to ESH-18 10/1/97 35-003(o) 32.5 8/6/1997 35-7 YES NO NO NO Removed Building 35-7. Covered with gravel for old building, asphalt around old building, and soil at perimeter. YES NO Ten Site Berm down slope of site detains run-off which then trickles down slope towards canyon. YES Asphalt parking up slope. NO NO D. Mays NO Fix hole in earth berm. Remove straw bales which have mostly decayed. Pick up trash at NE corner of PRS inside berms. 35-003(p) 50.8 9/24/1997 35-7 YES NO NO NO Location of former Building 35-7, removed 1996. Former building location leveled and stabilized with base course. Slight slope to NE. YES YES Two areas; 1) gully forming at NE end, through hole in earth berm; 2) sheet flow along old road north of PRS. Stormwater runoff from site is either diverted into catch basins or culverts which discharge to Pratt or Ten Site Canyon away from down slope PRSs 35-003(d,l,q). Gap in berm allowing water through, forming rill. YES Parking access upslope. NO All operations ceased, all facilities removed. NO D. Mays Additional run-on BMPs are planned for FY99. Earth berm along east end of PRS. Storm Water catch basins and culverts are directing flow from this site around other downslope PRSs. NO Berm has been fixed and curlex was placed on patched areas. 35-003(q) 59.0 8/6/1997 35-7 NO YES NO NO Down slope from former Building 35-7. YES YES Earth berm stabilized with jute mat, diverts run-off to riprap-lined channel leading to Pratt Canyon, tributary to Ten Site Canyon. YES Former building upstream Building 35-7. NO NO D. Mays More revegetation effort is needed. BMP in place: Earth berm to divert run-off to riprap-lined channel. Area backfilled and reseeded 1996. Additional work completed in 12/98 included fixing breached berm, provided extra riprap and compaction of soils at site NO Rill/gully erosion is beginning to form at interim action site. 35-003(r) 87.0 8/20/1997 NO NO YES YES PRS encompasses entire Pratt Canyon. Close to 75% on average, but since it's the whole drainage, it varies. Steep at upper reaches; gradual at base. YES YES Natural channel at base of canyon. Pratt Canyon is a tributary of Ten Site Canyon, which in turn flows into Mortandad Canyon. Gully at upper reach at outlet of earth berm located down slope of former Building 35-7. YES Collects parking lot and roof drain runoff from TA-35. YES Fire hydrant. YES From upstream sources. D. Mays Remove any trash/debris, particularly from canyon floor. Check dams were installed in the bottom of Pratt Canyon to dissipate flow and to retain sediment. NO Since this is an entire canyon, it contains at least one example of most features normally associated with erosion. However, the flat area leading up to the "cattail area" acts as its own sedimentation/infiltration field. As a result of this volume reduction, the runoff from the entire PRS can pass through a single 12" iron pipe under a roadway which, according to ER representatives, has not been breached. 35-004(a) 3.6 7/30/1997 YES NO NO NO Asphalt parking lot. All asphalt. NO NO NO NO NO D. Mays NO No soil erosion potential. However, any contaminants on site would flow downhill into canyon. 35-004(b) 22.3 7/30/1997 YES NO NO NO Asphalt pad. NO NO YES Run-on from adjacent building and sheet flow across asphalt pad. NO NO T. Lemke NO 35-004(c) 3.6 9/24/1997 35-125 YES NO NO NO South side of structure, Building 125, at large secondary containment unit. Covered secondary containment unit - completely in concrete and asphalt. Level surface NO NO NO NO NO R. Reynolds NO 35-004(g) 3.6 7/30/1997 YES NO NO NO 100% Asphalt. NO NO NO NO NO D. Mays NO 35-004(h) 50.8 9/24/1997 35-7 YES NO NO NO Location of former Building 35-7, removed 1996. Former building location leveled and stabilized with base coarse. Slight slope to NE. YES YES Two areas; 1) gully forming at NE end, through hole in earth berm; 2) sheet flow along old road north of PRS. Stormwater runoff from site is either diverted into catch basins or culverts which discharge to Pratt or Ten Site Canyon away from down slope PRSs 35-003(d,l,q). Gap in berm allowing water through, forming rill. YES Parking access upslope. NO All operations ceased, all facilities removed. NO D. Mays Additional run-on diversion BMPs are planned for FY99 NO Berm has been fixed and curlex was placed on patched areas (12/98) 35-004(i) 3.6 9/24/1997 35-29 YES NO NO NO Parking lot north of Building 35-29. 100% asphalt. Flat. NO NO NO No run-on from upper parking lot. NO NO D. Mays NO 35-004(j) 3.6 9/24/1997 35-128 YES NO NO NO SW corner of Building 35-128. Loading dock/storage pad. 100% asphalt + concrete. NO NO NO NO This wing no longer used for "Sample Management" (SMO). NO D. Mays Stabilization with asphalt - no maintenance required. NO 35-004(m) 3.6 8/20/1997 YES NO NO NO South of Building 35-86. Asphalt driveway, concrete curb & gutter. NO NO NO No roof drains, floor drains, or particularly concentrated roadway runoff. NO NO D. Mays Remove trash/debris. NO 35-004(o) 3.6 9/24/1997 35-213 YES NO NO NO Former solvent/chemical storage area. Currently dumpster for flattened cardboard north of Building 35-213. 100% asphalt. Flat. NO NO NO NO NO D. Mays NO 35-005(a) 45.6 8/21/1997 YES NO NO NO Thick grass and ragweed cover. YES YES Rill forming at Mortandad Canyon rim, at NW corner of PRS. NO NO YES Slight sheet flow run-on from surrounding areas. D. Mays Remove trash/debris from rill, just over canyon rim, at NW corner of PRS. NO PRS 35-006 was removed and replaced by 35-005(a) in 1985. 35-005(a) was subsequently removed in 1989. 35-005(b) 8/21/1997 35-125 NO NO NO NO Could not locate PRS in the field. NO NO NO NO NO D. Mays NO 35-006 45.6 8/21/1997 YES NO NO NO Thick grass and ragweed cover. YES YES Rill forming at Mortandad Canyon rim, at NW corner of PRS. NO NO YES Slight sheet flow run-on from surrounding areas. D. Mays Remove trash/debris from rill, just over canyon rim, at NW corner of PRS. NO PRS 35-006 was removed and replaced by 35-005(a) in 1985. 35-005(a) was subsequently removed in 1989. 35-007 3.6 9/24/1997 35-125 YES NO NO NO South side of structure, Building 125, at large secondary containment unit. Covered secondary containment unit - completely in concrete and asphalt. Level surface NO NO NO NO NO R. Reynolds NO 35-008 61.0 6/4/1997 NO YES NO NO Within a tributary on slope/bench. Leaves, needles, rock, dead tree branches. Ponderosa canopy cover. Exposed soils. YES YES 24" corrugated metal pipe (CMP) discharges into adjacent drainage. Upper reach, below TA-50 outfall. None visible. Vegetation increases below site. YES Storm culvert. NO NO S. Veenis Straw mulch should be placed over loose sediments to help keep them in place. NO Trash is plastic and misc. debris.
Visible debris/oil staining evident on upper slope area. No debris or oil was observed below (about 100 ft) site where vegetation in dense. Migration is not obvious in field.35-009(a) 22.3 7/30/1997 YES NO NO NO Area of septic tank under asphalt (0 - 25%). Leach fields (75 - 100%). NO NO YES Asphalt parking area provides run-on to leach fields. Septic tank under asphalt. NO NO T. Lemke NO 35-009(b) 3.6 7/30/1997 YES NO NO NO 100% Asphalt. NO NO NO NO NO D. Mays NO 35-009(c) 18.3 8/21/1997 35-125 NO YES NO NO Along road north of Building 35-2 parking lot. Roadway itself is pretty bare, but there is good rock and vegetation over edge of canyon. Very gradual slope of roadway. NO NO NO NO NO Slight run-on from upslope area (sheet flow). D. Mays NO There is trash below the end of the mesa, but is neither in a watercourse nor within the PRS boundary. 35-009(d) 32.8 8/6/1997 YES NO NO NO YES YES Approximately 50 feet east of CMP, which is below building 35-33. NO NO NO D. Mays NO 35-009(e) 18.3 7/30/1997 YES YES NO NO Site on mesa top, but SWMU goes to canyon bottom. Building 35-25 there is thick vegetation Asphalt: <10%. Canyon: >30%. NO NO NO Former septic tank beneath asphalt, so run-on is not an issue. NO NO D. Mays NO 35-010(a) 20.8 8/6/1997 NO NO YES NO Decommissioned wastewater treatment lagoons, used 1975-1992. Concrete lagoon walls, grass and weeds in lagoon floor. NO NO NO NO NO D. Mays NO Drain pipes not plugged, but for them to allow water out, the lagoons would have to fill to 1.0-1.5 m depth. This is extremely unlikely. 35-010(b) 20.8 8/6/1997 NO NO YES NO Decommissioned wastewater treatment lagoons, used 1975-1992. Concrete lagoon walls, grass and weeds in lagoon floor. NO NO NO NO NO D. Mays NO Drain pipes not plugged, but for them to allow water out, the lagoons would have to fill to 1.0-1.5 m depth. This is extremely unlikely. 35-010(c) 20.8 8/6/1997 NO NO YES NO Decommissioned wastewater treatment lagoons, used 1975-1992. Concrete lagoon walls, grass and weeds in lagoon floor. NO NO NO NO NO D. Mays NO Drain pipes not plugged, but for them to allow water out, the lagoons would have to fill to 1.0-1.5 m depth. This is extremely unlikely. 35-010(d) 15.6 8/6/1997 NO NO YES NO Covered with sand, underlain with thick membrane. 0% slope NO NO NO NO NO D. Mays NO No storm water concerns - flow eliminated by pan evaporation filter beds. 35-010(e) 24.8 8/6/1997 NO NO NO YES NO NO NO This is the outfall from PRS 35-010(d). However, there does not appear to be any flow through the sand filter drain. NO NO D. Mays NO 35-014(a) 10.6 8/20/1997 YES NO NO NO Undisturbed soil samples near tritium process stack. Residential quality lawn. NO NO NO NO YES Only run-on is naturally occurring from surrounding areas. D. Mays NO AIR POLLUTION SITE - INTERPRET WITH CAUTION. This is not a solid/liquid pollution site, for which the AP 4.5(b) erosion assessment was designed, but the region around a stack. Accordingly, it should be interpreted with care. Note added by D. Mays, per instruction from M. Alexander, 9/15/97. 35-014(c) 15.3 9/24/1997 35-29 YES NO NO NO Former spill location, since cleaned up at SE corner of Building 35-29. 100% asphalt. Slopes down to culvert, draining to Pratt Canyon, covered by PRSs 35-016(k) and 35-016(l). NO NO NO NO NO D. Mays Sealed with asphalt - no maintenance required. NO 35-014(d) 15.8 8/20/1997 YES NO NO NO SW corner of Building 35-29. Combination riprap, grass & soil. NO NO YES Parking lot. NO NO D. Mays Stabilization with base course. NO 35-014(e) 61.0 6/4/1997 NO YES NO NO Within a tributary of a slope/bench. Leaves, needles, rock, dead tree branches. Ponderosa canopy cover. Exposed soils. YES YES 24" CMP discharges into adjacent drainage. Upper reach, below TA-50 RLW outfall. None visible. Vegetation increases below site. YES 24" CMP discharges onto the site. NO NO S. Veenis Straw mulch should be placed over loose sediments to help keep them in place. NO Trash is plastic and misc. debris. Visible debris/oil staining evident on upper slop area. No debris or oil was observed below (about 100 ft) site where vegetation is dense. Migration was not obvious in the field. 35-014(e2) 45.6 9/24/1997 YES NO NO NO Thick grass and ragweed cover. YES YES Rill forming at Mortandad Canyon rim at northwest corner of PRS. NO NO YES Slight sheet flow run-on from surrounding areas. D. Mays Remove trash and debris from rill just over canyon rim at NW corner of PRS. NO 12b) Misc. trash/debris at NW corner of PRS, over Mortandad Canyon rim.
35-006 was removed and replaced by 35-005(a) in 1985. 35-005(a) was subsequently removed in 1989.35-014(f) 3.6 8/21/1997 YES NO NO NO Parking area east of Building 35-128. PRS backfilled and stabilized with base course; surrounding area asphalt. NO NO NO NO NO PRS protected by adjacent Building 35-128. D. Mays NO 35-014(g) 39.8 8/20/1997 YES NO NO NO 35-016(n) consists of a daylight channel N of Building 35-207; culvert under walkway; channel to edge of mesa. 35-014(g1) is an oil spill at the culvert entrance. Thick grass in upper daylight channel, then thick scrub oak, then over grassy channel passing over bare volcanic tuff. Upper shallow slope; lower medium slope. YES YES Northeast of building 35-207 Channel discharges directly into Ten Site Canyon. Looks stable and well vegetated. Volcanic tuff exposed in channel. YES Runoff from parking area near Building 35-207. NO NO D. Mays NO Looks benign, compared to other 35-016 sites. 35-014(g2) 3.6 8/20/1997 35-86 YES NO NO NO South of Building 35-86. Asphalt driveway, concrete curb & gutter. NO NO NO No roof drains, floor drains, or particularly concentrated roadway runoff. NO NO D. Mays Remove trash/debris. NO 35-014(g3) 39.8 8/20/1997 YES NO NO NO Oil spill on road upslope from former tank farm. Mostly asphalt pavement. YES YES Two routes to canyon: 1) along side of road, onto recently concrete-lined channel, through gully; 2) through series of culverts. Channels are man-made, so there is no unusual erosion, beyond the natural mesa top sheet flow. YES Roadway runoff; storm water from former tank farm area. NO NO D. Mays Clean up trash/debris in westernmost gully, downstream from concrete lined channel. NO 35-015(a) 3.6 8/20/1997 35-86 YES NO NO NO Former tank farm. Half of site is concrete pad; remainder, base course and/or low vegetation. NO NO NO Roof drain does not route flow to former oil tank farm. NO NO Concrete curb prevents run-on. D. Mays NO 35-015(b) 34.6 8/20/1997 YES NO NO NO Parking lot/driveway between Buildings 35-29 and 35-2. Asphalt. Flat. YES NO Sheet flow off asphalt. YES PRS is currently under parking lot. NO NO D. Mays NO 35-016(a) 92.0 8/20/1997 35-34 NO YES YES NO Gully leading to Ten Site Canyon, smaller than 35-016(q). Some growth in upper gully; less below de facto sediment pond dam. Upper shallow; lower steep. YES YES 12" iron pipe inactive, so gully is now natural only. NO NO Inactive NPDES outfall 04A089 YES Rainfall runoff only. D. Mays Backfill and compact to return mesa top to sheet flow runoff. Then, re-establish vegetation. YES Gully has caved in about 20 feet above outlet of inactive 12" iron pipe, creating a "de facto" sediment pond of about 4 foot depth. 35-016(b) 96.0 8/20/1997 35-87 NO YES YES NO Steep slope to Ten Site Canyon. Almost no cover. Steep. YES YES 6" PVC line, installed 1977. Deep, well-defined gully. YES 18" CMP for parking lot runoff is adjacent to the PRSs main 6" PVC. YES 6" PVC permitted under NPDES (06A132). YES Gully collects natural run-on. D. Mays Remove trash/debris from gully. Suggest installation of rock check dam and/or velocity dissipater at bottom of gully. Broken asphalt and concrete curb/gutter sections at outfall for velocity dissipation. No maintenance required for this BMP. YES 35-016(c) 47.2 7/30/1997 YES YES NO NO PRS extends from canyon edge to bench within Ten-Site Canyon. Vegetation Primarily brush on slope. YES YES Bench of Ten Site Canyon Very little vegetation at site of old outfall. Evidence of sheet flow erosion in this area. YES Run-on from asphalt north of site. NO YES Sheet flow from surrounding slopes. T. Lemke NO Steep slope with little vegetation at site of old outfall. 35-016(d) 76.5 8/20/1997 35-46 NO YES NO NO Steep slope down to Ten Site Canyon. Brush in watercourse, mostly dead & down. YES YES 6" VCP inactive, but still dripping from groundwater inflow into pipe system. Therefore, channel is now natural. Established gully leading down slope to Ten Site Canyon floor. Littered with concrete curb & gutter segments with some thick vegetation. Most soil has already been washed away. YES Parking lot runoff through 12" CMP discharging in the air about 5-10 feet above 6" VCP. NO YES Natural run-on into gully. D. Mays Remove trash/debris, though old concrete gutter sections should remain as a splashguard for the 12" CMP. NO 35-016(e) 72.0 7/30/1997 35-85 YES YES NO NO PRS extends from outfall to bench within Mortandad Canyon. Site primarily bare soil, rock and broken asphalt. YES YES Storm water outfall. Erosion around culvert and along bank of channel. YES Storm drain NO Former NPDES outfall 04A090 YES Sheet flow from surrounding slopes. T. Lemke Remove visible debris. Provide sediment transport control, i.e., straw bales. NO Evidence of sediment transport in channel and little to no vegetation along channel banks. 35-016(f) 76.5 7/30/1997 35-85 YES YES NO NO PRS extends from outfall to bench within canyon. Ground cover primarily pine needles and light vegetation. Canopy of bushes and trees. YES YES Run-off has formed a gully at outfall, extending down slope. YES Storm waste outfall. NO YES Sheet flow down slope. T. Lemke Flow dissipation and sediment transport controls (check dams, straw bales). NO Steep slope with little vegetation in channel. 35-016(g) 68.3 8/21/1997 NO YES NO NO Through bench to Mortandad Canyon. Thick canopy cover; thick undergrowth. Upper 10-30%; lower near-drop-off. YES YES Gully down canyon wall. Less severe than PRS 35-016(h), but still significant. NO YES NPDES permit number EPA-04A127. NO D. Mays Remove trash/debris. NO 35-016(h) 76.5 8/21/1997 35-213 NO YES NO NO Culvert outlets onto drainage gully on west side of Building 35-213. On east side of this building, runoff flows along south side of canyon access road. Some shotcrete; some shrub vegetation; some bare soil. Steep descent into Mortandad on west side. On east side, flows along fire road leading to canyon bottom. YES YES Three culvert outlets combine to form gully on west side. Approximately 20 feet deep, 30 feet wide at top on west side. On east side, drainage within vegetated ditch. YES Parking lot runoff only. NO NO D. Mays Remove trash/debris. NO 12b) Misc. trash/debris at NW corner of PRS, over Mortandad Canyon rim. 35-016(i) 61.0 7/30/1997 35-85 YES YES NO NO PRS boundary extends from outfall on mesa top to bench within Mortandad Canyon. Runoff from outfall flows primarily along rock to bottom of canyon. YES NO Storm water & floor drain outfall. YES Run-on from building drains & parking lots. NO YES Sheet flow from sub-drainage, steep slope. T. Lemke Remove visible debris. Provide flow dissipation and sediment transport controls. NO Sediment transport possible along bench within the canyon. Evidence of sediment accumulation along bench. 35-016(j) 24.0 8/21/1997 NO YES NO NO Outfall in shotcrete slope, then 40-50 feet to canyon rim. Shotcrete, then pine needles and pine/deciduous canopy cover. NO NO YES 4" VCP, active since 1975. NO NO D. Mays NO 35-016(k) 53.0 8/6/1997 YES NO NO NO PRS 35-016(k) outfalls directly into CMP. Outlet of CMP is PRS 35-016(l). Mixed vegetation along drainage channel. Mostly culvert. Slope varies through culvert and channel. YES YES Drainage channeling run-off from culvert towards Pratt Canyon. End of culvert discharges directly onto broken up concrete/asphalt on steep slope above Pratt Canyon. Outlet from 2nd culvert into Pratt Canyon has created gully about 5 feet deep and 20 feet long. NO YES Cooling water outfall from Building 35-29. Former NPDES outfall 04A116, storm water only now. NO D. Mays Clean up trash - 5 minute job. Flow dissipation and stabiliztion of banks at culvert discharge area. NO Trash: cans, plastic and pieces of iron (all very small). 35-016(l) 64.0 8/6/1997 35-29 YES NO NO NO PRS 35-016(k) outfalls directly into CMP. Outlet of CMP is PRS 35-016(l). YES YES Drainage channeling run-off from culvert towards Pratt Canyon. Outlet from 2nd culvert into Pratt Canyon has created gully about 5 feet deep and 20 feet long. NO YES Cooling water outfall from Building 35-29. NO D. Mays Clean up trash - 5 minute job. Flow dissipation at culvert discharge area. NO Trash: cans, plastic and pieces of iron (all very small). 35-016(m) 72.0 8/20/1997 NO YES NO NO Steep slope into Pratt Canyon, a tributary of Ten Site Canyon. Little vegetation at base of concrete-lined channel. YES YES Concrete-lined drainage channel. Erosion has undercut last 10 feet of the concrete channel, beyond the fence. YES Parking lot runoff. NO Cooling tower never went on-line. Furthermore, cooling tower outfalls (2" iron pipe and 6" iron pipe) are now capped. YES Numerous small rills leading down towards concrete channel at fence. D. Mays Remove trash/debris. Apply geotextile/jutemat to slope to foster revegetation. NO 35-016(n) 42.8 8/20/1997 35-207 YES YES NO NO 35-016(n) consists of a daylight channel N of Building 35-207; culvert under walkway; channel to edge of mesa and beyond. 35-014(g1) is an oil spill at the culvert entrance. Thick grass in upper daylight channel, then thick scrub oak, then over grassy channel passing over bare volcanic tuff. Upper shallow slope; lower medium slope. YES YES Culvert directs local runoff into channel Ten Site Canyon located below. Looks stable and well vegetated. YES Runoff from Building 35-207. NO NO D. Mays NO Looks benign, compared to other 35-016 sites. Site originally assessed 8/20/97, minor adjustment performed 6/15/98 to reflect updated information on PRS boundary. Formerly delivered to NMED on 1/7/98. 35-016(o) 60.3 8/20/1997 35-2 NO YES NO NO On steep slope into Mortandad Canyon below Building 35-2. Thick growth. Steep, but not steep enough for fall protection requirements. YES YES 6" iron pipe, 6" PVC pipe and 4" iron pipe comprise 35-016(o). PRS 35-016(p) is a 24" CMP. Outfall flow, plus some natural run-on, combine to form rill. YES PRS consists of roof drain/floor drain outfalls. NO YES D. Mays Remove trash/debris. Install riprap for velocity attenuation. NO 35-016(p) 60.3 8/20/1997 35-27 NO YES NO NO On steep slope into Mortandad Canyon below Building 35-2. Thick growth. Steep, but not steep enough for fall protection requirements. YES YES 6" iron pipe, 6" PVC pipe and 4" iron pipe comprise 35-016(o). PRS 35-016(p) is a 24" CMP. Outfall flow, plus some natural run-on, combine to form rill. YES PRS consists of roof drain/floor drain outfalls. NO YES D. Mays Remove trash/debris. Install riprap for velocity attenuation. NO 35-016(q) 92.0 8/20/1997 35-110 NO YES YES NO Major gully south of Building 35-110, starting at canyon rim and cutting down to Ten Site Canyon floor. Gully cuts through former landfill. No ground or canopy cover. Bare soil down to canyon floor. YES YES Gully - see photo. Gully terminates at base of descent, but does not connect directly to Ten Site watercourse. Gully about 20-30 feet deep. NO NO YES Run-on from sheet flow off mesa top. D. Mays NO Flow dissipation devices are needed. 35-018(a) 15.8 8/20/1997 YES NO NO NO SW corner of Building 35-29. Combination riprap, grass & soil. NO NO YES Parking lot. NO NO D. Mays Stabilization with base course. BMPs installed 6/30/96 NO C-35-004 73.5 9/24/1997 35-125 YES NO NO NO One-time spill of dielectric mineral oil (non-PCB). CMP coverage 80-100% shotcrete - to edge of hillside. End of CMP undercut back under hillside. Eroded hillside completely visible from below. Steep south facing. YES YES Culvert (CMP) serving as conveyance from south side of 35-125 to Ten Site Canyon. Steep canyon slope. Undercut embankment under stabilized bank and end of CMP. YES Roof and road run-on. NO YES R. Reynolds Complete erosion work at end of CMP. Will talk to Facility Manager about starting this work. NO C-35-005 73.5 9/24/1997 YES NO NO NO One time spill of dielectric mineral oil (non-PCB). CMP coverage 80-100% shotcrete - to edge of hillside. End of CMP undercut back under hillside. Eroded hillside completely visible from below. Steep south facing. YES YES Steep canyon slope. Undercut embankment under stabilized bank and end of CMP. YES Roof and road run-on. NO YES R. Reynolds Complete erosion work at end of CMP. Will talk to Facility Manager about starting this work. NO C-35-007 39.5 9/24/1997 35-215 NO NO YES NO North of decommissioned TA-35 sand filter beds on Ten Site Canyon floor. Sand piles beginning to support vegetation, about 25% vegetation. Slopes toward sand filters to south. NO NO Some sheet flow at west end of AOC, but no evidence in engineered drainage channel south of AOC, north of sand beds. Some visible evidence along access road. Infiltration NO NO YES Run-on from canyon wall and access road - not a major concern. D. Mays Run-on diversion dike. NO