There is no detailed map available for TA-4

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

04-001

45.0

5/1/2001

YES

YES

NO

NO

4-001 - former firing pit now covered with approximately 15 cubic feet of solid (spoils pile placed by FSS.  Located on mesa top near mesa edge.

Mesa has mixed vegetation with some barren areas.  Canop cover consists of Ponderosa pines.

Site mostly flat, gently sloping towards Ten Site Canyon to the North

YES

NO

Sheet flow with gentle swale located within PRS boundary.

Bench below site

Runoff appears to terminate on bench below site.

None observed.

NO

No structural impacts

NO

YES

Sheet flow run-on from area above site near spoils piles.

Veenis, Steve

NO

Site impacted be Cerro Grande Fire.  BMPs are in place to reduce run-on to slope below.  Site originally assessed on 8/27/97.

04-002

51.5

8/27/1997

YES

YES

NO

NO

4-002 - canyon side disposal area located below 04-001.  Site believed to exist on slope above Ten Site Canyon.

Mostly rock and some minor vegetative cover with ponderosa canopy.

Cliff face of above bench setting.

YES

YES

Run-on from mesa edge discharges onto slope which has several drainage channels.

Bench setting above canyon

Runoff appears to terminate on bench above Ten Site Canyon.

No erosion features observed, the drainages are natural with PRS boundary.

NO

No structural impacts.

NO

No operational impacts.

YES

Sheet flow run-on from mesa top above.

Veenis, Steve

Site reseeded and mulched.  Straw wattles are placed in several locations.

NO

Site impacted by Cerro Grande Fire.  BMPs were placed to dissipate flow and to re-establish vegetation.  Orignal assessment performed on 8/27/97.

04-003(a)

57.3

8/27/1997

YES

NO

NO

NO

Former TA-4-7, currently identified in TA-52, former building west of 52-115.

a)  Shallow trench containing former waste line. c)  Former TA-4-7 site well vegetated.

YES

YES

Old back hoe trench corridor.

Former outfall discharge to Canada del Buey.

Most erosion occurring at lower end of PRS along back side of Building 115, discharging to deeper eroded channel approximately 3/4 deep leading to Canada del Buey.

YES

Building run-on from adjacent trailer and parking lot.

NO

YES

R. Reynolds

1) Re-establish vegetative cover on trench line. 2) Sediment retention dams (natural or rock) in discharge channel.

NO

04-003(b)

51.5

5/1/2001

YES

YES

NO

NO

4-003(b) - trench (former) outfall from building (removed). Outfall discharged over mesa edge onto slope below.  .

Site mostly rocks with mixed vegetation along slope.  Mixed ponderosa pine and shrub canopy.

Cliff face is steep going towards bench below.

YES

NO

Sheet flow run-off evidence exists.  No channelization is occurring.  Drainage channels are naturally occurring.

bench setting below site

Runoff terminates on bench setting below site.

None observed.

NO

No structural impacts

NO

No operational impacts

YES

Sheet flow drainage onto site from above.

Veenis, Steve

Site re-seeded and mulched.  Straw wattles are installed throughout the site.

NO

Site impacted by Cerro Grande Fire. BMPs installed to mitigate erosion potential.

04-004

57.3

8/27/1997

YES

NO

NO

NO

Former TA-4-7, currently identified in TA-52, former building west of 52-115.

a)  Shallow trench containing former waste line. c)  Former TA-4-7 site well vegetated.

YES

YES

Old back hoe trench corridor.

Former outfall discharge to Canada del Buey.

Most erosion occurring at lower end of PRS along back side of Building 115, discharging to deeper eroded channel approximately 3/4 deep leading to Canada del Buey.

YES

Building run-on from adjacent trailer and parking lot.

NO

YES

R. Reynolds

1) Re-establish vegetative cover on trench line. 2) Sediment retention dams (natural or rock) in discharge channel.

NO