There is no detailed map available for TA-42

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

42-001(a)

65.8

3/3/1998

55-05

YES

NO

NO

NO

42-001(a) incinerator bldg.  42-001(b,c) ash holding tanks.  42-002(b) outdoor decon area.  D&D in 1979-80.  42-002(a) indoor decon area.

Mostly grass and weeds, some pine trees.

Flat to edge of canyon to cliff.

YES

YES

Run-on and run-off has caused severe gully channels.

Gullies discharge into canyon.

Severe gully erosion found in 3 locations.

YES

Roadway discharges from TA-55 access road (designated as wetland?)

YES

NPDES (SW drains?) discharges causing most of erosion (03A181) 55-6.

NO

S. Veenis

Flow dissipation and hard armor (rip rap?) of channels.

NO

12 a):  Minor cans/trash

42-001(b)

65.8

3/3/1998

55-05

YES

NO

NO

NO

42-001(a) incinerator bldg.  42-001(b,c) ash holding tanks.  42-002(b) outdoor decon area.  D&D in 1979-80.  42-002(a) indoor decon area.

Mostly grass and weeds, some pine trees.

Flat to edge of canyon to cliff.

YES

YES

Run-on and run-off has caused severe gully channels.

Gullies discharge into canyon.

Severe gully erosion found in 3 locations.

YES

Roadway discharges from TA-55 access road (designated as wetland?)

YES

NPDES (SW drains?) discharges causing most of erosion (03A181) 55-6.

NO

S. Veenis

Flow dissipation and hard armor (rip rap?) of channels.

NO

12 a):  Minor cans/trash

42-001(c)

65.8

3/3/1998

55-05

YES

NO

NO

NO

42-001(a) incinerator bldg.  42-001(b,c) ash holding tanks.  42-002(b) outdoor decon area.  D&D in 1979-80.  42-002(a) indoor decon area.

Mostly grass and weeds, some pine trees.

Flat to edge of canyon to cliff.

YES

YES

Run-on and run-off has caused severe gully channels.

Gullies discharge into canyon.

Severe gully erosion found in 3 locations.

YES

Roadway discharges from TA-55 access road (designated as wetland?)

YES

NPDES (SW drains?) discharges causing most of erosion (03A181) 55-6.

NO

S. Veenis

Flow dissipation and hard armor (rip rap?) of channels.

NO

12 a):  Minor cans/trash

42-002(a)

65.8

3/3/1998

55-05

YES

NO

NO

NO

42-001(a) incinerator bldg.  42-001(b,c) ash holding tanks.  42-002(b) outdoor decon area.  D&D in 1979-80.  42-002(a) indoor decon area.

Mostly grass and weeds, some pine trees.

Flat to edge of canyon to cliff.

YES

YES

Run-on and run-off has caused severe gully channels.

Gullies discharge into canyon.

Severe gully erosion found in 3 locations.

YES

Roadway discharges from TA-55 access road (designated as wetland?)

YES

NPDES (SW drains?) discharges causing most of erosion (03A181) 55-6.

NO

S. Veenis

Flow dissipation and hard armor (rip rap?) of channels.

NO

12 a):  Minor cans/trash

42-002(b)

65.8

3/3/1998

55-05

YES

NO

NO

NO

42-001(a) incinerator bldg.  42-001(b,c) ash holding tanks.  42-002(b) outdoor decon area.  D&D in 1979-80.  42-002(a) indoor decon area.

Mostly grass and weeds, some pine trees.

Flat to edge of canyon to cliff.

YES

YES

Run-on and run-off has caused severe gully channels.

Gullies discharge into canyon.

Severe gully erosion found in 3 locations.

YES

Roadway discharges from TA-55 access road (designated as wetland?)

YES

NPDES (SW drains?) discharges causing most of erosion (03A181) 55-6.

NO

S. Veenis

Flow dissipation and hard armor (rip rap?) of channels.

NO

12 a):  Minor cans/trash

42-003

35.8

1/13/2000

55-05

YES

YES

NO

NO

Septic tank and drain line - drain field discharged over mesa edge onto small canyon bench.  Septic tank was  removed during D&D operations in the 1970's.  Upto 15 ft of crushed tuff/backfill now cover the former septic tank location (fill was added for a proposed building site).

Top of mesa has upto 15 ft of crushed tuff/backfill over the former septic tank location.  Side slopes of fill are well vegetated. Drain field is well vegetated and covered with needles, rock etc.

Flat on top, small gradient to bench and then steep over canyon edge.

YES

NO

Small area where former discharges occurred.

Former drain field discharged onto canyon bench and then into canyon. No current erosion, Storm water does not reach this area.

None observed.

NO

NO

NO

J. Walterscheid

NO

12 a):  minor debris on bench.                                                                                                                                                  Site revisit completed by J. Walterscheid on 1/13/00. Original site visit completed on 3/13/98.

42-004

93.5

3/3/1998

NO

NO

YES

YES

Canyon disposal area.

Dense canopy, ground cover moderate with rocks and pine needles.

Over canyon edge.

YES

YES

Gullies from above discharging onto site.  Drainage channels exist throughout hillside.

Run-off into canyon via channels on hillside.

From discharges above.

YES

From roadway north of TA-55.

YES

NPDES outfall 03A181 also runs through other PRSs.

YES

S. Veenis

Flow dissipation needed in gullies.

NO

Construction debris throughout slope.