QUALITY ASSURANCE/QUALITY CONTROL
Maryland Department of Natural Resources followed specific procedures to ensure that the Tributary component of the Chesapeake Bay Water Quality Monitoring Program design was properly implemented and managed with sufficient accuracy, precision and detection limits. Accuracy (closeness to the true value) of collected data was controlled and assured by proper use, calibration and maintenance of both field and laboratory equipment for the measurement of physical and chemical parameters.
The procedures used to control and assure the accuracy of field measurements involved the calibration of field instruments, the verification of calibrations, and equipment maintenance. Most of the details of how data acquired with YSI sondes and Hydrolab sondes were quality assured and quality controlled are described in the process description elements in the Lineage portion of this metadata record.
Daily quality control checks which included the running of blanks and standards were used to control and assure laboratory accuracy.
Accuracy of Chesapeake Biological Laboratory, Nutrient Analytical Services Laboratory (CBL NASL) and Maryland Department of Health and Mental Hygiene (DHMH) results was also assessed through DNR's participation in the Chesapeake Bay Coordinated Split Sample Program (CSSP) a split sampling program in which five laboratories involved in Chesapeake Bay monitoring analyze the coordinated split samples. CSSP was established in June 1989 to establish a measure of comparability between sampling and analytical operations for water quality monitoring throughout the Chesapeake Bay and its tributaries. The Chesapeake Bay Program Data Integrity Workgroup (formerly AMQAW) oversees the CSSP. DNR followed the protocols in the Chesapeake Bay Coordinated Split Sample Program Implementation Guidelines (EPA 1991) and its revisions. Split samples were collected quarterly. Results were analyzed by appropriate statistical methods to determine if results differed significantly among labs. If a difference occurred, discussions began regarding techniques and potential methods changes to resolve discrepancies.
January 2018: The shorelines and most of the river were frozen when stations POT1595 and POT1596 samples were collected. Shoreline ice was also noted in field data sheets for stations MON0020, MON0155, POT2766, TOW0030 and NBP0689. Large chunks of ice were floating in the river and piled up along the edges at station POT2386. Near station DER0015, possible effects of flowing ice on the gage and discharge were observed. Ice was forming in the river when station WIL0013 samples were collected. The waters at stations ANA0082, PXT0972, MON0269 and XGG8251 were described as 100 percent, 99 percent, 90 percent and 50 percent ice covered, respectively. Heavy rains during the weekend prior to sampling were noted on field sheets for stations WIL0013, POT2766, BDK0000 and NBP0103. Rain fell preceding sampling at stations CON0180 and CON0005. Didymo was not visible at station SAV0000. When station ANT0366 was sampled, presence of road salt was noted both on the bridge and along the road. The water level was high at station NBP0534 due to release of water from the dam upstream. The gage and the discharge at station PAT1076 were frozen. The discharges at stations GWN0115, NPA0165, PAT0285 and JON0184 were frozen.
February 2018: Readings at station PAT0176 were double checked using a second meter. Sensor post-calibration checks for pH 10 were not conducted on the water quality sonde used for sampling at stations DER0015, CB1.0, GUN0476 and GUN0258. Didymo was not seen at station SAV0000. There was snow on the ground at stations MON0155, CAC0031 and POT1596. The MON0020 Bridge was icy. The water at station BPC0035 was very brown. Snow and freezing rain occurred the day before sampling at stations BPC0035, MON0528, MON0269, CAC0148, POT1830, and ANT0044. Heavy rains and snowmelt occurred the weekend prior to sampling at stations WIL0013, BDK0000, POT2766 and TOW0030. Rainfall and snowmelt during the weekend preceding sample collection was noted at stations NBP0103, NBP0023 and NBP0326. The station NBP0326 water level was described as very high.
March 2018: The station WIL0013 pH results were double checked using a second meter. Braddock Run water was very clear at station BDK0000. Didymo was not seen at station SAV0000. Pure sewage was observed discharging from the outflow pipe at station GEO0009 and the effluent was reported to the Maryland Department of the Environment.
April 2018: Construction at station PXT0809 was ongoing. There were scattered showers the day before sampling operations at station TF1.0. A cold front preceded sample collection at station RCM0111. Rainfall occurred the night before the following sites were sampled: DER0015, CB1.0, GUN0476, GUN0258, MON0155, CAC0031, POT1596, POT1595, MON0020, POT1147, POT1472 and SEN0008. High river water levels were observed at stations POT1595, MON0528, MON0020, MON0269, POT1471 and POT1472. Rain showers occurred prior to sample collections at stations MON0528, MON0269, CAC0148, POT1830 and NBP0461. Heavy rain fell the Sunday preceding sampling at stations ANT0203, ANT0366, CON0180, CON0005 and NBP0023. High river flows were noted at stations POT1830 and ANT0044. The water levels at stations ANT0203, CON0005 and NBP0023 were very high. Similarly, the water level at station ANT0366 was high. Waters at stations MON0269, POT1830 and ANT0203 were muddy. The trail leading to station POT2386 was flooded and large debris floated in the river.
May 2018: Descriptions of heavy thunderstorms during the preceding few days were noted on field data sheets for stations WIL0013, BDK0000, NBP0103, POT2766, TOW0030, SAV0000, GEO0009, NBP0461 and NBP0326. The water level at station POT2386 was high and the river was murky. Heavy rain over the prior few days was noted at station NBP0023. Rain fell during the few days before station NBP0689 was sampled. A hydrograph of station NBP0534 was described as rising due to rain over the past few days.
June 2018: The Patapsco river, at stations PAT0176 and PAT0285, was high and muddy. The water level was high at station GUN0125. Scattered showers fell during sampling at station GUN0475. Heavy rain, over the weekend preceding sampling, was noted at stations MON0155, CAC0031 and POT1596. The ramps at stations MON0155 and POT1596 were flooded. There was flooding at station POT1471. The river was flowing over the bank at station TF1.0. Heavy rains during the night prior to sampling were noted at stations WIL0013, NBP0103 and NBP0023. Extremely high water levels were noted at stations WIL0013 and NBP0103 and a very high water level was logged at station POT2386. There was a large buildup of debris and trash on the upstream side of the CON0005 Bridge.
July 2018: Station POT0159 sampling was conducted from Point of Rocks Bridge due to bridge construction at the normal site. Field notes for station CON0005 recorded the presence of debris under the bridge and construction on the upstream side of the bridge. A downpour occurred prior to sampling operations at station NBP0103. Station POT2766 samples were collected from the beach upstream of the bridge. Evidence of the influence of Braddock Run was noted when station WIL0013 was sampled. Station YOU0925 field notes stated rain in McHenry and dry in Friendsville. Orange colored water was noted at station GEO0009. Didymo was present at station SAV0000.
August 2018: Rain fell the night prior to sampling at stations ANT0044, BPC0035, CAC0148, MON0269, MON0528, POT1830, CB1.0, DER0015, GUN0258 and GUN0476. Station MON0528 field sheet notes observed that that the river flow rate on 22-Jul-2018 was 10,900 cubic feet per second. Station CB1.0 notes stated that the rate of water flow over Conowingo Dam was 400,000 cubic feet per second on 26-Jul-2018. Samples for station POT1471 were collected from the ramp. The creek was very muddy when station DER0015 samples were collected. Heavy rain fell during the week prior to sampling at station PAT0176. The water had a high level and a dark color when station ANT0203 was sampled. Debris blocked more than half of the CON0005 bridge. Storms occurred on the Tuesday prior to station POT2386 sampling and the water was dark. Heavy rain occurred in the area of station NBP0103. Downpours prior to sampling were noted at stations WIL0013 and YOU0925. Rainfall preceded sampling at station POT2766 and samples were collected upstream of the bridge. The water level at station GEO0009 was high. Heavy rain fell the night before samples were collected at stations GEO0009, NBP0326, NBP0461 and NBP0534. Heavy rains fell the day before, overnight and during the morning preceding, sampling at stations NBP0689. SAV0000 and YOU1139. Algae (not Didymo) covered the rocks at station SAV0000.
September 2018: The Susquehanna River rose one foot after samples were collected at station CB1.0. There appeared to be a flood tide when samples were collected at station ANA0082. Station PXT0809 dissolved oxygen readings were double checked with meter 5. The arrival of Hurricane Florence was remarked in sampling notes 17-Sep-2018 when stations ANT0203, ANT0366, CON0005, CON0180 and POT2386 were surveyed. Hurricane Florence was noted in 18-Sep-2018 in comments for stations BDK0000, CAS0479, NBP0023, NBP0103, POT2766, TOW0030, WIL0013 and YOU0925. 19-Sep-2018 sample collections at stations GEO0009, LYO0004, NBP0326, NBP0461, NBP0534, NBP0689, SAV0000 and YOU1139 also noted Hurricane Florence. Debris covered three quarters of the creek when station CON0005 was sampled. Rain poured when station POT2386 was sampled. The station NBP0023 bridge was submerged and samples were collected from the riverbank. When station POT2766 was sampled, the water level was bank top and samples were collected from the bank upstream.
October 2018: A station PAT0107 field data sheet comment stated that the Bloede Dam had been breached upstream since September 2018 samples were collected. Water levels were high at stations CB1.0, MON0020, MON0155, POT1471, POT1472, POT1595 and POT1596. Similarly, the waters at station GUN0258 were characterized as elevated. The pre-existing large island of debris at station NBP0023 had washed away.
November 2018: The water level at station PIS0033 was very high. The river was high and muddy at stations ANT0203, ANT0044, CAC0031, SEN0008, MON0020, MON0155, MON0269, POT1472 and POT1595. The water at station POT1472 was described as high and muddy but not as dark as the water on the Maryland side at station POT1471. The banks at station ET5.0 were flooded. Station CB1.0 samples were collected 50 feet downstream of the normal location. Debris piled up along 2/3 the length of the station CON0005 bridge. The river was high at station CON0180 and there was flooding adjacent to the USGS gage. The water level was up at station MON0528 and high at station CAC0148. The river at station POT1830 was at flood stage. Station MON0155 samples were collected at the boat launch. Rain fell during the night prior to sampling at stations NBP0023, NBP0103, NBP0326, NBP0461 and TOW0030. Station TOW0030 sampling operations were conducting during the peak of flow. Rain fell during the early morning of the day before samples were collected at stations NBP0534, NBP0689 and SAV0000. Rain fell during the day and the night before sampling at station WIL0013. The United States Geological Survey listed turbidity as 54 NTU when samples were collected at station PAT0176.
December 2018: Station TF1.0 pH sensor post-calibration results fell outside of the acceptable range. The Secchi disk measurement at station XGG8521 exceeded the station total water depth and salinity results were double-checked using a second sonde. Station POT1472 conductivities were double checked using a second sonde. Rain fell the weekend prior to sample collection at stations BDK0000, GEO0009, LYO0004, NBP0023, NBP0326, NBP0461, NBP0689, POT2766, SAV0000, TOW0030 and WIL0013. A large pile of debris blocked three quarters of the station CON0005 bridge. The water level at station NBP0534 reached the top of the river bank. The bridge at station NBP0023 was flooded and samples were collected from the bank on the Maryland side. Station NBP0534 conductivity results were not considered reliable, possibly due to inadequate submersion of the sensor.