VAW-L13L_ROA03A02 - Roanoke River from the Smith Mountain Dam downstream to the Pigg River confluence. |
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WQS Class IV Sec. 6h PWS (WQS Roanoke River Basin Table p. 131) Assessment basis: DEQ station 4AROA158.22 (Ambient water quality station (AQ)- Surface only) located at Smith Mountain Dam. No stations above Pigg River in Leesville Reservoir due to releases from Smith Mountain Dam. No VDH Fish Consumption or Drinking Water Advisories. 4AROA158.22- Surface- Escherichia coli (E.coli), dissolved oxygen (DO), temperature, pH, total phosphorus (TP), chlorophyll a (CA), ammonia (NH3-N), nitrates and chlorides each Fully Support. Fecal coliform (FC) is not assessed in this AU as it is downstream of SML Dam where surface collection is made. Carlson Trophic State Index (TSI): chlorophyll a (CA) [35.6] TP [39.7] Seechi Disk (SD) [44.0] - TSI scores all less than 60- Full Support. --------------------------------------------------------- Historical Information - not assessed for 2006: 4AROA158.22- No excursions of the sediment Probable Effects Concentration (PEC) screening values (SVs) are found from AQ 1998 or 1999 collections. |
VAW-L13L_PGG01A02 - Pigg River from its confluence with the Roanoke River in Leesville Lake upstream to its backwaters. |
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WQS Class III Sec. 6a None (WQS Roanoke River Basin Table p. 130) Assessment basis: DEQ station 4APGG003.29 (AQ, '99 fish tissue (FT) and 4AROA153.59 (AQ). Pigg R. & Old Womans Creek Bacteria TMDL Study is due for completion in the spring of 2006. No VDH Fish Consumption or Drinking Water Advisories. 4APGG003.29- Surface -Five of 12 Escherichia Coli (E.coli) exceed the 235 cfu/100 ml instantaneous criterion. The range of exceeding values is from 300 cfu/100 ml to greater than 800. The station is located in the immediate backwaters of Leesville Reservoir. No excursions of the free flowing total phosphorus screening value (SV) of 0.20 mg/l are found in the data. Compared to the reservoir total phosphorus (TP) SV of 0.05 mg/l where four of 18 samples exceed ‘Observed Effect’. DO, Temp, pH, NH3-N, nitrates and chlorides each Fully Support. AQ 2000 sediment collection finds no excursions of the PEC SVs. Data are insufficient to make a trophic status determination. 1999 fish tissue collection finds no excursions of the WQS based Tissue Values (TVs) or EPA Risked Based (IRIS Database) TSVs for tissue. No exceedances from a total of 22 fish. Species include Largemouth Bass, Carp, Yellow Perch and Redhorse Sucker. No Walleye collected. ------------------------------------------------------ Historical Information - not assessed for 2006: 4APGG003.29- A 1993 Tier 2 fish tissue study (1993 Roanoke River Basin Study DEQ, Water Research & Standards, Richmond, Virginia ) found polychlorinated biphenyls (PCBs) in one of five species in excess of the tissue value (TV ) of 54 parts per billion (ppb); Walleye (65.6 max.), from a total of 50 fish. 1999 sediment collection finds no excursions of the PEC SVs. |
VAW-L13L_ROA02A02 - Roanoke River from the Pigg River mouth downstream to the Old Womans Creek mouth. |
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WQS Class IV Sec. 6h PWS (WQS Roanoke River Basin Table p. 131) Assessment basis: DEQ stations 4AROA153.59 (AQ- Surface only), 4AROA145.34 (AQ) and 4AROA140.66 ('99 FT). Previously 2002 listed for DO (bottom layer). No additional data beyond 2003. Pigg R. & Old Womans Creek Bacteria TMDL Study is due for completion in the spring of 2006. No VDH Fish Consumption or Drinking Water Advisories. 4AROA153.59- Located downstream of the Pigg River confluence in the reservoir, reports TSI scores of chlorophyll a (CA) [41.5], TP [47.4] and seechi disk (SD) [63.5]. The station is not stratified. The SD reading is indicative of turbidity. No reservoir bottom data (below the thermocline) are reported. The parameter of preference is chlorophyll a with a TSI score of 41.5, well below the 60 TSI. DO, Temp, pH, TP, chlorophyll a, NH3-N, nitrates and chlorides all Fully Support. 4AROA145.34- Surface - DO, Temp, pH, TP, chlorophyll a, NH3-N, nitrates and chlorides each Fully Support. Six of 69 DO measurements did exceed the 4.0 mg/l minimum criterion. Carlson Trophic State Index (TSI): TSI - Chlorophyll a [45.3] TP [42.7] Seechi Disk [54.1] - TSI scores all less than 60- Full Support. FC exceeds in one of nine samples - insufficient to assess. Escherichia coli (E.coli) exceed the 235 cfu/100 ml instantaneous criterion in two of five observations resulting in the overall AU Category 5A designation. Values in excess of the criterion are 375 and 500 cfu/100 ml. Bottom- DO exceeds the 4.0 mg/l minimum in 14 of 110 measurements. Category 4C - DO exceedances at depth natural based on TSI scores above. Temp, TP, NH3-N, nitrates and chlorides each Fully Support. 4AROA140.66- 1999 fish tissue collections find no excursions of the WQS TVs or Risked Based TSVs. -------------------------------------------------------- Historical Information - not assessed for 2006: 4AROA145.34- TSI: CA [46.86] TP [41.50] Seechi Disk [50.28]. |
VAW-L13L_ROA01A02 - Roanoke River from the mouth of Old Womans Creek downstream to Leesville Dam. |
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WQS Class IV Sec. 6h PWS (WQS Roanoke River Basin Table p. 131)
Assessment basis: DEQ station 4AROA140.66 (AQ, '99 FT)
Pigg R. & Old Womans Creek Bacteria TMDL Study is due for completion in the spring of 2006.
No VDH Fish Consumption or Drinking Water Advisories. 4AROA140.66- Surface -FC, Temp, TP, chlorophyll a, NH3-N, nitrates and chlorides each Fully Support. Carlson Trophic Index (TSI): TSI - Chlorophyll a [42.1] TP [42.2] Seechi Disk [51.3] - TSI scores all less than 60- Full Support. DO exceeds the minimum 4.0 mg/l criterion in 14 of 78 measurements. An extremely dry period occurred within the assessment data window contributing to these excursions. The TSI scores do not indicate an overwhelming human influence, eg. TSIs greater than 60. Three of 19 pH measurements exceed the WQS maximum range of 9.0 SU at 9.3 and two measurements at 9.1 SU. Because of the DO and pH excursions of their respective criterion the overall AU is categorized 5C until further data clarifiy conditions in the reservoir and/or WQ Standards address these conditons in reservoirs. Bottom - DO exceeds the 4.0 mg/l minimum criterion in 56 of 180 measurements. DO exceedances at depth are natural based on TSI scores above. Temp, TP, NH3-N nitrates and chlorides each Fully Support. 4AROA140.66- 1999 fish tissue collections find no excursions of the WQS TVs or Risked Based TSVs. --------------------------------------------------------- Historical Information - not assessed for 2006: 4AROA140.66- TSI: CA [44.73] TP [41.14] SD [48.86]. 1998 fish tissue collection did report one species, Stripped Bass, at 52.2 ppb below the WQS TV of 54 ppb- Fully Supporting. 1999 sediment collection finds no excursions of the PEC SVs. |
VAW-L13L_OWC01A02 - Old Womans Creek from its confluence with the Roanoke River upstream to its backwaters. |
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WQS Class III Sec 6a None (WQS Roanoke River Basin Table p. 130) Assessment basis: DEQ stations 4AOWC001.00 ('99 FT) Pigg R. & Old Womans Creek Bacteria TMDL Study is due for completion in the spring of 2006. No VDH Fish Consumption or Drinking Water Advisories. 4AOWC001.00- WQS 1999 fish tissue (TV) collections find no excursions of the WQS based TVs or Risk Based TSVs. Sediment collections also fully support with no excursions of the PEC SVs. No additional reservoir data are available, trophic status is not determined. -------------------------------------------------------- Historical Information - not assessed for 2006: 4AOWC001.00- 1998 fish tissue collections find no excursions of the WQS based TVs or Risk Based TSVs. Sediment also Fully Supports with no excursions of the PEC SVs. |
