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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
46-002 52.8 9/30/2000   YES NO NO YES Inactive sanitary lagoons and outfall.  Lagoons located on mesatop with outfall discharging into channel that goes to SWSC Canyon. Lagoons have total concrete enclosure. The formerly permitted outfall discharged to the south of the lagoons. Slope is gradual to the south into SWSC Canyon. YES YES Old discharge overflow pipe is plugged.  Formerly discharged into a channel created by outfall.     Discharges terminated directly into SWSC Canyon. Does not currently discharge, there are no sources currently going into the drainage channel. NO No structural impacts YES Former NPDES outfall SSS07S NO No upslope drainage. S. Veenis   Earthen berm placed around lower sand filter bed area and then covered with geotextile. NO Original assessment performed on 10/8/97 with a score of 3.6.  The outfall was not included and should have been.
46-003(h) 8.8 7/12/1999   YES NO NO NO Former outfall east end of TA-46 Rocky area with sparse grasses.  Large tree provides good canopy coverage. Flat area near building. NO NO No evidence of runoff       None observed. NO No roof drains from nearby building. NO No operations NO None Veenis, Steve     NO  
46-004(a) 30.5 10/1/1997   YES YES NO NO Outfall from edge of mesa top to bench within Canada del Buey. Canopy cover of pine and oak.  Ground cover of various types of grasses. >30% from mesa top to bench.  <10% along bench. NO NO           YES Drainage from buildings and asphalt areas. NO   YES Sheet flow from surrounding slope. T. Lemke     NO Adequate ground cover in this area.
46-004(a2) 30.5 10/1/1997   YES YES NO NO Outfall from edge of mesa top to bench within Canada del Buey. Canopy cover of pine and oak.  Ground cover of various types of grasses. >30% from mesa top to bench.  <10% along bench. NO NO           YES Drainage from buildings and asphalt areas. NO   YES Sheet flow from surrounding slope. T. Lemke     NO Adequate ground cover in this area.
46-004(b)   11/24/1997   NO NO NO NO This PRS does not exist.  The LANL ER program has no record of its existence.  Therefore this site could not be located and field evaluated.     NO NO           NO   NO   NO   T. Lemke     NO  
46-004(b2) 27.5 11/26/1997 46-1 YES NO NO NO 4 inch VCP located on the east side of TA-46-1.   PRS located on bare slope adjacent to TA-46-1. NO NO           NO   NO   YES Some sheet flow over hillside. C. McLean     NO  
46-004(c) 30.5 10/1/1997   YES YES NO NO Outfall from edge of mesa top to bench within Canada del Buey. Canopy cover of pine and oak.  Ground cover of various types of grasses. >30% from mesa top to bench.  <10% along bench. NO NO           YES Drainage from buildings and asphalt areas. NO   YES Sheet flow from surrounding slope. T. Lemke     NO Adequate ground cover in this area.
46-004(c2) 30.5 10/1/1997   YES YES NO NO Outfall from edge of mesa top to bench within Canada del Buey. Canopy cover of pine and oak.  Ground cover of various types of grasses. >30% from mesa top to bench.  <10% along bench. NO NO           YES Drainage from buildings and asphalt areas. NO   YES Sheet flow from surrounding slope. T. Lemke     NO Adequate ground cover in this area.
46-004(d) 30.5 10/1/1997   YES YES NO NO Outfall from edge of mesa top to bench within Canada del Buey. Canopy cover of pine and oak.  Ground cover of various types of grasses. >30% from mesa top to bench.    <10% along bench. NO NO           YES Drainage from buildings and asphalt areas. NO   YES Sheet flow from surrounding slope. T. Lemke     NO Adequate ground cover in this area.
46-004(d2) 56.0 11/24/1997   YES YES NO NO Area of potential contamination from stack emissions is on the mesa top.  Drainage pathways for potential contaminates are within a bench of Canada del Buey.  Evaluated between Storm Water stations T461 and CB46. Canopy cover of pine and oak.  Limited ground cover.  Areas of heavy forest liter. >30% from edge of mesa top to bench.

>10% on mesa top and along bench.
YES YES Natural drainage channel down side of canyon and along bench. Canada del Buey     Rill erosions align the bench. YES Drainage from buildings, asphalt and storm drains. NO   YES Sheet flow from surrounding slope. T.l Lemke   NPDES Status cont.  04A117 deleted 7/11/95 NO Areas of bare soil and evidence of sediment transport and deposition.  Assessment data provided by information gathered from a field visit to the area on 10/1/97.

Paper, aluminum foil, Styrofoam, and other debris scattered around and in drainage.
46-004(e) 30.5 10/1/1997   YES YES NO NO Outfall from edge of mesa top to bench within Canada del Buey. Canopy cover of pine and oak.  Ground cover of various types of grasses. >30% from mesa top to bench.  <10% along bench. NO NO           YES Drainage from buildings and asphalt areas. NO   YES Sheet flow from surrounding slope. T. Lemke     NO Adequate ground cover in this area.
46-004(e2)   11/24/1997   NO NO NO NO This PRS could not be located and field evaluated.     NO NO           NO   NO   NO   T. Lemke     NO  
46-004(f) 37.6 10/8/1997 46-76 YES YES NO NO All outfalls/storm drains tie into inactive NPDES - discharge into canyon. Roof drains/industrial areas. Source on mesa/outfall onto steep slope. YES NO Discharge into heavily vegetated slope.     Culvert under roadway. None visible. YES Roadway run-off onto site. NO Inactive 04A018 (deleted 12/95). NO   S. Veenis     NO Remove storm drain sources?
46-004(f2)   11/24/1997   NO NO NO NO This PRS could not be located and field evaluated.     NO NO           NO   NO   NO   T. Lemke     NO  
46-004(g) 56.0 10/1/1997   YES YES NO NO Area of potential contamination for stack emissions is on the mesa top.  Drainage pathways for potential contaminates are within a bench of Canada del Buey.  Evaluated between Storm Water stations T461 and CB46. Canopy cover of pine and oak.  Limited ground cover.  Areas of heavy forest litter. >30% from edge of mesa top to bench.

>10% on mesa top and along bench.
YES YES Natural drainage channel down side of canyon and along bench. Canada Del Buey     Rill erosion along the bench. YES Drainage from buildings, asphalt and storm drains. NO   YES Sheet flow from surrounding slope. T. Lemke   Installed jute and straw bale dams in drainage. NO Areas of bare soil and evidence of sediment transport and deposition.

Paper, aluminum foil, Styrofoam, and other debris scattered around and in drainage.
46-004(h) 56.0 10/1/1997   YES YES NO NO Area of potential contamination for stack emissions is on the mesa top.  Drainage pathways for potential contaminates are within a bench of Canada del Buey.  Evaluated between Storm Water stations T461 and CB46. Canopy cover of pine and oak.  Limited ground cover.  Areas of heavy forest litter. >30% from edge of mesa top to bench.

>10% on mesa top and along bench.
YES YES Natural drainage channel down side of canyon and along bench. Canada Del Buey     Rill erosion along the bench. YES Drainage from buildings, asphalt and storm drains. NO   YES Sheet flow from surrounding slope. T. Lemke     NO Areas of bare soil and evidence of sediment transport and deposition.

Paper, aluminum foil, Styrofoam, and other debris scattered around and in drainage.
46-004(i) 30.5 10/1/1997   YES YES NO NO Outfall from edge of mesa top to bench within Canada del Buey. Canopy cover of pine and oak.  Ground cover of various types of grasses. >30% from mesa top to bench.  <10% along bench. NO NO           YES Drainage from buildings and asphalt areas. NO   YES Sheet flow from surrounding slope. T. Lemke     NO Adequate ground cover in this area.
46-004(j) 30.5 10/1/1997   YES YES NO NO Outfall from edge of mesa top to bench within Canada del Buey. Canopy cover of pine and oak.  Ground cover of various types of grasses. >30% from mesa top to bench.  <10% along bench. NO NO           YES Drainage from buildings and asphalt areas. NO   YES Sheet flow from surrounding slope. T. Lemke     NO Adequate ground cover in this area.
46-004(k) 17.5 10/8/1997 46-158 YES NO NO NO Inactive outfall. Heavy canopy and grasses.   YES NO Matted down grass and leaves.   Infiltrates     NO   NO Inactive 03A124 (deleted 12/95) YES From above outfall. S. Veenis     NO Visible trash around site.
46-004(l) 3.6 10/8/1997 46-24 YES NO NO NO Outfall? Total asphalt cover/no WC issues!   NO NO           NO   NO   NO   S. Veenis     NO  
46-004(m) 30.5 10/1/1997   YES YES NO NO Outfall from edge of mesa top to bench within Canada del Buey. Canopy cover of pine and oak.  Ground cover of various types of grasses. >30% from mesa top to bench.  <10% along bench. NO NO           YES Drainage from buildings and asphalt areas. NO   YES Sheet flow from surrounding slope. T. Lemke     NO Adequate ground cover in this area.
46-004(n) 17.5 10/8/1997 46-41 YES NO NO NO Inactive NPDES outfall. Total asphalt coverage.   YES YES Discharge into southwest culvert under 46-314.   Ditch/vegetative swale     YES Parking/roadway run-on. NO Inactive 04A117 (deleted 7/95). NO   S. Veenis     NO Plug culvert?
46-004(o) 15.8 11/26/1997 46-200 YES NO NO NO Former NPDES outfall associated with TA-46-200.  Outfall is located at the northwest corner of the building, adjacent to a storm water conveyance.  Outfall is capped. Area vegetated with grass, no canopy cover.   NO NO Outfall has been capped.         YES Run-on from roof drain from TA-46-200. NO Outfall is deleted NPDES outfall EPA-03A-136. NO   T. Lemke     NO Outfall is no longer active and the area is well vegetated. 

Discharge from a roof drain has caused a small channel to form between the drain and the former NPDES outfall.  The channel is not present downstream from the outfall.
46-004(p) 3.6 10/8/1997 46-1 YES NO NO NO Sump. Asphalt area/totally enclosed.   NO NO           NO   NO   NO   S. Veenis     NO  
46-004(q) 30.5 10/1/1997   YES YES NO NO Outfall from edge of mesa top to bench within Canada del Buey. Canopy cover of pine and oak.  Ground cover of various types of grasses. >30% from mesa top to bench.  <10% along bench. NO NO           YES Drainage from buildings and asphalt areas. NO   YES Sheet flow from surrounding slope. T. Lemke   Installed jute and straw bale dams in drainage. NO Adequate ground cover in this area.
46-004(r) 37.6 10/8/1997 46-76 YES YES NO NO All outfalls/storm drains tie into inactive NPDES - discharge into canyon. Roof drains/industrial areas. Source on mesa/outfall onto steep slope. YES NO Discharge into heavily vegetated slope.     Culvert under roadway. None visible. YES Roadway run-off onto site. NO Inactive 04A018 (deleted 12/95). NO   S. Veenis     NO Remove storm drain sources?
46-004(s) 27.5 11/26/1997 46-1 YES NO NO NO 4 inch cast iron pipe approximately 25 feet south of TA-46-1.  Pipe served as the outfall for floor and roof drains inside 46-1.  This outfall is no longer active.  Located on soil slope adjacent to building.   Close to 10%. NO NO         Small rill leading from outfall to Storm Water conveyance. YES Run-off off roof of building. NO   YES Small amount of sheet flow. C. McLean     NO This outfall is no longer active and the rill formed by previous discharges is vegetating.
46-004(t) 68.3 10/8/1997 46-76 YES NO NO NO Grass area 46-008(g) within fence.

Outfall - 46-004(t).

AOC 46-001 - historic spill.
Heavy vegetation - grasses. Culvert discharges under road down steep area. YES YES Culvert under road into SWSC canyon.       At end of culvert into canyon. YES Roadway run-off. NO Inactive 04A014 (deleted 7/95). NO   S. Veenis     NO Remove or plug culvert if possible.
46-004(u) 30.5 10/1/1997   YES YES NO NO Outfall from edge of mesa top to bench within Canada del Buey. Canopy cover of pine and oak.  Ground cover of various types of grasses. >30% from mesa top to bench.  <10% along bench. NO NO           YES Drainage from buildings and asphalt areas. NO   YES Sheet flow from surrounding slope. T. Lemke     NO Adequate ground cover in this area.
46-004(v) 30.5 10/1/1997   YES YES NO NO Outfall from edge of mesa top to bench within Canada del Buey. Canopy cover of pine and oak.  Ground cover of various types of grasses. >30% from mesa top to bench.  <10% along bench. NO NO           YES Drainage from buildings and asphalt areas. NO   YES Sheet flow from surrounding slope. T. Lemke     NO Adequate ground cover in this area.
46-004(w) 37.6 10/8/1997 46-76 YES YES NO NO All outfalls/storm drains tie into inactive NPDES - discharge into canyon. Roof drains/industrial areas. Source on mesa/outfall onto steep slope. YES NO Discharge into heavily vegetated slope.     Culvert under roadway. None visible. YES Roadway run-off onto site. NO Inactive 04A018 (deleted 12/95). NO   S. Veenis     NO Remove storm drain sources?
46-004(x) 30.5 10/1/1997   YES YES NO NO Outfall from edge of mesa top to bench within Canada del Buey. Canopy cover of pine and oak.  Ground cover of various types of grasses. >30% from mesa top to bench.  <10% along bench. NO NO           YES Drainage from buildings and asphalt areas. NO   YES Sheet flow from surrounding slope. T. Lemke     NO Adequate ground cover in this area.
46-004(y) 30.5 10/1/1997   YES YES NO NO Outfall from edge of mesa top to bench within Canada del Buey. Canopy cover of pine and oak.  Ground cover of various types of grasses. >30% from mesa top to bench.  <10% along bench. NO NO           YES Drainage from buildings and asphalt areas. NO   YES Sheet flow from surrounding slope. T. Lemke     NO Adequate ground cover in this area.
46-004(z) 30.5 10/1/1997   YES YES NO NO Outfall from edge of mesa top to bench within Canada del Buey. Canopy cover of pine and oak.  Ground cover of various types of grasses. >30% from mesa top to bench.  ,10% along bench. NO NO           YES Drainage from buildings and asphalt areas. NO   YES Sheet flow from surrounding slope. T. Lemke     NO Adequate ground cover in this area.
46-005 52.8 9/30/2000   YES NO NO YES Lined lagoons with overflow discharge pipe to NPDES outfall.  The outfall discharges directly into a channel that flows to SWSC Canyon. Lined lagoons with outfall discharging into channel with moderate vegetative cover. Moderate slope to the north into SWSC Canyon. YES YES Formerly discharged into channel created by outfall.     Discharges terminated into SWSC Canyon. Does not currently discharge, there are no current sources into the drainage channel. NO No structural impacts. YES Potential exists although debris at outfall indicates that there has not been a discharge.  EPA-SSS12S, TA-46-OX-PD. NO No upslope sources. Veenis, Steve     NO Original assessment completed on 10/20/97 with a score of 3.6.  The outfall was not included and should have been.
46-006(a) 30.5 10/1/1997   YES YES NO NO Outfall from edge of mesa top to bench within Canada del Buey. Canopy cover of pine and oak.  Ground cover of various types of grasses. >30% from mesa top to bench.  <10% along bench. NO NO           YES Drainage from buildings and asphalt areas. NO   YES Sheet flow from surrounding slope. T. Lemke     NO Adequate ground cover in this area.
46-006(b) 10.6 10/8/1997 46-41 YES NO NO NO Storage area - void 008(e) photo here. Total asphalt cover - vegetative buffer on south side +/- 15 feet wide.   NO NO SW culvert runs under site.         YES Parking area and roadway. NO   NO   S. Veenis     NO  
46-006(c) 30.3 10/8/1997 46-158 NO NO NO NO Operational release east side of 46-158. Asphalt covered. Flat before entering storm drain. YES YES Culvert discharges from area storm catch basin. SWSC Canyon       YES Roof and parking area run-on. NO   NO   S. Veenis     NO Visible trash around site.
46-006(d) 30.5 10/1/1997   YES YES NO NO Outfall from edge of mesa top to bench within Canada del Buey. Canopy cover of pine and oak.  Ground cover of various types of grasses. >30% from mesa top to bench.  <10% along bench. NO NO           YES Drainage from buildings and asphalt areas. NO   YES Sheet flow from surrounding slope. T. Lemke     NO Adequate ground cover in this area.
46-006(f) 34.6 10/8/1997 46-277 YES NO NO NO Storage area. Total asphalt cover.   YES YES Site drains directly into culvert-asphalt channel plus backhoe cut into tuff - "outfall m."     Via culvert to "outfall m." Not at actual site. YES Adjacent parking lot. NO   NO   S. Veenis     NO Adequate ground cover in this area.
46-007 22.8 10/1/1997   YES YES NO NO Outfall from edge of mesa top to bench within Canada del Buey. Canopy cover of pine and oak.  Ground cover of various types of grasses. >30% from mesa top to bench. NO NO           YES Drainage from buildings and asphalt areas. YES NPDES outfalls:  4(i) -   03A044         4(j) -   03A042

                           4(y) - 03A043         4(m) - 04A013

                           6(a) - 03A042
YES Sheet flow from surrounding slope. T. Lemke     NO Adequate ground cover in this area.
46-008(a) 17.5 10/8/1997 46-88 YES NO NO NO East of 46-88 - storage area. Asphalt covered area drains onto heavily vegetated area.   YES NO Yes from asphalt portion of site - PRS boundary does not have channelized run-off (see map).   Infiltrates     YES Adjacent parking area. NO   NO   S. Veenis Pick up debris.   NO Visible debris on asphalt pad.
46-008(b) 22.8 10/1/1997   YES YES NO NO Outfall from edge of mesa top to bench within Canada del Buey. Canopy cover of pine and oak.  Ground cover of various types of grasses. >30% from mesa top to bench. NO NO           YES Drainage from buildings and asphalt areas. YES NPDES outfalls:  4(i) -   03A044         4(j) -   03A042

                           4(y) - 03A043         4(m) - 04A013

                           6(a) - 03A042
YES Sheet flow from surrounding slope. T. Lemke     NO Adequate ground cover in this area.
46-008(d) 10.6 10/8/1997 46-24 YES NO NO NO South 46-24 - old storage area.     NO NO           YES Minimal from asphalt channel on west edge. NO   NO   S. Veenis     NO  
46-008(e) 3.6 10/8/1997 46-187 YES NO NO NO Storage pad. Asphalt cover with grasses growing within.   NO NO           NO   NO   NO   S. Veenis     NO Office salvage stuff.
46-008(f) 17.5 10/8/1997 46-25 YES NO NO NO Storage area and drainage on west side of 46-25. Grass in ditch/asphalt adjacent.   YES YES Along edge of asphalt and tuff cliff.   Ditch Infiltrates into ditch.   YES Roadway/parking area. NO   NO   S. Veenis     NO  
46-008(g) 68.3 10/8/1997 46-76 YES NO NO NO Grass area 46-008(g) within fence.

Outfall - 46-004(t).

AOC 46-001 - historic spill.
Heavy vegetation - grasses. Culvert discharges under road down steep area. YES YES Culvert under road into SWSC canyon.       At end of culvert into canyon. YES Roadway run-off. NO Inactive 04A014 (deleted 7/95). NO   S. Veenis     NO Remove or plug culvert if possible.
46-009(a) 57.0 1/13/2000 46-41 YES NO YES NO Land disposal of concrete and construction material south 46-41. Weeds, grasses and brush on slope.  Brush, trees, grasses at toe of slope. Debris slope from road cut is steep but flattens towards the canyon bottom. YES NO Mostly sheet flow.     Sheetflow runoff terminates into SWSC Canyon. Rill erosion prevalent throughout slope. YES Roadway run-on. NO   NO   S. Veenis     NO Concrete, asphalt, construction debris on slope and into canyon bottom.    Site rescored per SWAT recommendation.  Original score 70 on 11/6/97.  New score on 1/13/00 of 57.0 based on revaluation of run-off factors.  Performed by JCW.
46-009(b) 70.0 10/8/1997   NO YES NO NO Bench above SWSC plant - old filter bed. Chamisa and sand. Beds on flat bench - sloped south off bench towards SWSC. YES YES Total concrete curb enclosure at filter - off slope run-off channelized.     Off bench. Off southern slope towards SWSC plant. NO   NO Inactive o7S YES   S. Veenis     NO Run-off/run-on diversion.
46-010(f) 30.3 10/8/1997 46-158 NO NO NO NO Operational release east side of 46-158. Asphalt covered. Flat before entering storm drain. YES YES Culvert discharges from area storm catch basin. SWSC Canyon       YES Roof and parking area run-on. NO   NO   S. Veenis     NO Visible trash around site.
C-46-001 68.3 10/8/1997 46-76 YES NO NO NO Grass area 46-008(g) within fence.

Outfall - 46-004(t).

 C-46-001 - historic spill.
Heavy vegetation - grasses. Culvert discharges under road down steep area. YES YES Culvert under road into SWSC canyon.       At end of culvert into canyon. YES Roadway run-off. NO Inactive 04A014 (deleted 7/95). NO   S. Veenis     NO Remove or plug culvert if possible.