HomeMy WebLinkAbout2021-Appendix-IV---Chowan-SubbasinChowan – Appendix IV 1 2/18/2021
Appendix IV
Weight-Average Methodology
The reasoning behind this methodology is that the earlier years of monitoring collected multiple samples
within a single day, multiple samples within a single month on an irregular basis. This differs from the
current sampling regime which collects one sample per month. The intent of this method was to have a
historical distribution of samples that matched the current sampling regime. We maintained this
methodology throughout the report. The annual means for the water quality parameters presented in
appendix III, appendix IV, chapter 2, chapter 4, and chapter 5 were calculated using monthly averages
which were based on daily average values. First, the average daily values were calculated for each water
quality parameter, then the monthly average values were calculated from the daily average values. These
average monthly values were then used to calculate the yearly means. The five-year means and 2010 –
2018 means presented in Chapter 5 were calculated using a similar methodology using the yearly average
values to calculate the five year means.
NOTTOWAY RIVER AT US 258 NEAR RIVERDALE VA Ambient Monitoring Station Water Quality
Data with the Number of Samples Collected inside the Bar, Annual Weighted Means, and Annual
Median values with the Nottoway River Discharge (USGS Gage: 02047000).
Chowan – Appendix IV 2 2/18/2021
Chowan – Appendix IV 3 2/18/2021
Chowan – Appendix IV 4 2/18/2021
Chowan – Appendix IV 5 2/18/2021
Chowan – Appendix IV 6 2/18/2021
Chowan – Appendix IV 7 2/18/2021
BLACKWATER RIVER .5 MI UPS MOUTH NEAR WYANOKE Ambient Monitoring Station Water
Quality Data with the Number of Samples Collected inside the Bar, Annual Weighted Means, and
Annual Median values with the Backwater River Discharge (USGS Gage: 02049500).
Chowan – Appendix IV 8 2/18/2021
Chowan – Appendix IV 9 2/18/2021
Chowan – Appendix IV 10 2/18/2021
Chowan – Appendix IV 11 2/18/2021
Chowan – Appendix IV 12 2/18/2021
Chowan – Appendix IV 13 2/18/2021
CHOWAN RIVER NEAR RIDDICKSVILLE Ambient Monitoring Station Water Quality Data with the
Number of Samples Collected inside the Bar, Annual Weighted Means, and Annual Median values
with the Nottoway River Discharge (USGS Gage: 02047000).
Chowan – Appendix IV 14 2/18/2021
Chowan – Appendix IV 15 2/18/2021
Chowan – Appendix IV 16 2/18/2021
Chowan – Appendix IV 17 2/18/2021
Chowan – Appendix IV 18 2/18/2021
Chowan – Appendix IV 19 2/18/2021
CHOWAN RIVER AT US 13 AT WINTON Ambient Monitoring Station Water Quality Data with the
Number of Samples Collected inside the Bar, Annual Weighted Means, and Annual Median values
with the Nottoway River Discharge (USGS Gage: 02047000).
Chowan – Appendix IV 20 2/18/2021
Chowan – Appendix IV 21 2/18/2021
Chowan – Appendix IV 22 2/18/2021
Chowan – Appendix IV 23 2/18/2021
Chowan – Appendix IV 24 2/18/2021
Chowan – Appendix IV 25 2/18/2021
CHOWAN RIVER AT CHANNEL MARKER 16 NEAR GATESVILLE Ambient Monitoring Station Water
Quality Data with the Number of Samples Collected inside the Bar, Annual Weighted Means, and
Annual Median values with the Nottoway River Discharge (USGS Gage: 02047000).
Chowan – Appendix IV 26 2/18/2021
Chowan – Appendix IV 27 2/18/2021
Chowan – Appendix IV 28 2/18/2021
Chowan – Appendix IV 29 2/18/2021
Chowan – Appendix IV 30 2/18/2021
Chowan – Appendix IV 31 2/18/2021
CHOWAN RIVER AT CHANNEL MARKER 7 AT COLERAIN Ambient Monitoring Station Water
Quality Data with the Number of Samples Collected inside the Bar, Annual Weighted Means, and
Annual Median values with the Nottoway River Discharge (USGS Gage: 02047000).
Chowan – Appendix IV 32 2/18/2021
Chowan – Appendix IV 33 2/18/2021
Chowan – Appendix IV 34 2/18/2021
Chowan – Appendix IV 35 2/18/2021
Chowan – Appendix IV 36 2/18/2021
Chowan – Appendix IV 37 2/18/2021
CHOWAN RIVER AT US 17 AT EDENHOUSE Ambient Monitoring Station Water Quality Data with
the Number of Samples Collected inside the Bar, Annual Weighted Means, and Annual Median
values with the Nottoway River Discharge (USGS Gage: 02047000).
Chowan – Appendix IV 38 2/18/2021
Chowan – Appendix IV 39 2/18/2021
Chowan – Appendix IV 40 2/18/2021
Chowan – Appendix IV 41 2/18/2021
Chowan – Appendix IV 42 2/18/2021