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 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 2016: The Secchi disk measurement at station XGG8251 was greater than the station total depth. An extremely small amount of Didymo was present at station SAV0000. The upstream pipe at station NPA0165 was not discharging and 10 percent “fast” ice coverage was noted. PH data values measured at stations: PXT0809, PXT0972, CJB0005, POT1184, RCM0111 and ANA0082, were deemed unreliable due to pH probe failure. The water surface at station BPC0035 was 90 percent covered with ice. Ice coverage was 80 percent at stations MON0269 and CAC0148. Ice coverage was noted to be 100 percent upstream at station MON0528 and 25 percent of the river near station CAC0031 contained ice floes. Small amounts of ice were also noted at stations CON0180, NBP0689 and ANT0044. Heavy rains occurred two days before sampling at stations WIL0013 and TOW0030. High water level was noted at station POT2766. Above normal water clarity was observed at station GEO0009.
February 2016: Post-calibration readings of the pH probe for the following stations were 0.21 units higher than the pH standard: ANA0082, GUN0125, GWN0115, JON0184, NPA0165, PAT0176, PAT0285, PXT0972 and RCM0111. Snow on the ground was noted at stations: ANT0044, BPC0035, CAC0148, CB1.0, DER0015, GUN0476, GUN0258, MON0528, MON0269 and POT1830. Muddy water was observed at stations ANT0044, CAC0148, POT1184 and POT1830. Ice was seen at stations DER0015, MON0258, MON0269, POT1830, POT1595 and POT1596. Stations POT1595 and POT1596 were sampled under Potomac flood watch conditions. Snowmelt was noted at stations: ANT0203, ANT0366, CON0005, CON0180, POT2386 and NBP0326. Similarly, snowmelt, in the days preceding sampling, was noted at stations: BDK0000, GEO0009, NBP0103, NBP0023, NBP0461, NBP0534, NBP0689, POT2766, TOW0030 and WIL0013. Rain fell during sampling operations at stations: ANT0203, ANT0366, CON0005, CON0180, NBP0689 and POT2386. Station POT1596 was deemed bank full. The presence of lots of debris was noted at station POT1830. The Secchi disk measurement at station XGG8251 was greater than the station total depth. High water levels were described at stations: NBP0326, NBP0534, POT1184 and POT2766.
March 2016: Conowingo Dam on the Susquehanna was releasing water when station CB1.0 was sampled. The presence of new USGS turbidity probes was noted at stations: PAT0176, PAT0285 and GUN0258. Rain fell three days before stations WIL0013 and POT2766 were sampled. Rainfall the night before sampling was noted at the following stations: ANA0082, BDK0000, CAC0031, CJB0005, ET5.0, MON0020, MON0155, NBP0023, NBP0103, PXT0809, PXT0972, POT1184, POT1471, POT1472, POT1595, POT1596, POT2766, RCM0111, SEN0008 and TOW0030. The Secchi disk measurement at station XGG8251 was greater than the station total depth.
April 2016: The presence of an 8 inch boom at the river’s edge and new rocks at the ramp were noted at station CB1.0. When samples were collected at station NPA0165, the pipe was not discharging. Dissolved oxygen readings at station CAC0148 were checked using a second meter. A station SEN0008 field data sheet note stated "meter L pH reads 8.47". The occurrence of rain showers during the previous night was logged at station SAV0000.
May 2016: Three days of rainfall preceded sampling at stations: ANT0044, BPC0035, CAC0148, MON0269 and MON0528. Severe thunderstorms occurred during the night preceding sampling at stations CB1.0, DER0015, GUN0258 and GUN0476. Scattered showers, the night before sampling, were noted at stations: CAC0031, GEO0009, MON0155, MON0020, NBP0326, NBP0534, POT1471, POT1472, POT1595 and SEN0008. Rain fell the morning of sampling at stations: GEO0009, NBP0326 and NBP0534.The waters were described as high and muddy at the following stations: BPC0035, CAC0031, CAC0148, MON0020, MON0155, MON0269, POT1471, POT1472, POT1595, POT1596 and SEN0008. Bridge repairs were ongoing when stations ANT0044 and NBP0326 were sampled. The Secchi disk measurement at station XGG8251 was greater than 1 meter.
June 2016: Back flow of water at the wall was noted when station POT1184 was sampled. The discharge water at station POT2386, characterized as murky during sampling, continued to fall during collection. The level of the river at station ANA0082 was very low. At station CON0005, a field data sheet note indicated, that debris which had previously accumulated under the bridge had cleared.
July 2016: The river was muddy and above bank when samples were collected at TF1.0. Rain fell during the two day preceding sampling at station PXT092. A group of students on inner tubes passed prior to sampling at station ANT0044. A huge log dam, on the upstream side of the Station SEN0008 bridge, diverted 3/4ths of the river flow. When station CON0180 was sampled, the river was characterized as large and dirty with lots of tree debris. An increase in flow from 15 to 37 Cubic Feet per Second(CFS) was also noted. At station, CON0005 clear water was observed and contrasted to a plume upstream at station CON0180. A severe thunderstorm passed through shortly before station TOW0030 was sampled and sediment plumes were observed along both banks. Field data sheet notes entered at station GEO0009 described a peak in flow an hour before sampling, an increase in flow from 15 to 37 CFS and stated dark orange colored water.
August 2016: The occurrence of a record, 6-inches, rainfall 30-Jul-2016 was noted at stations: PAT0176, POT2386, PAT0285, GWN0115, NPA0165, JON0184, PXT0809, PXT0972, BPC0035 and CAC148. Sewage spills were noted in field log notes recorded at stations GWN0115, JON0184, PAT0175 (5 million gallons) and PXT0809 (2 million gallons). The hydrograph reading was still declining from the record rain when station POT2386 was sampled. Station PAT0285 flow went to 11300 CFS. The pipe at station NPA0165 was not discharging. Station BPC0035 flow went to 2100 CFS. Station CAC0148 flow went to 418 CFS. Braddock Run waters were noted across Wills Creek when station WIL0013 samples were collected. Water at station NBP0103 had an orange tint. A storm rolled in during station NBP0023 sampling and the waters were dark with higher sediment loads than usual. A storm passed just prior to sampling operations at station POT2766. A heavy storm preceded station TOW0030 sampling by half an hour. Rain fell during the morning before station NBP0689 samples were collected. Rain fell during the night before the following stations were sampled: NBP0534, SAV0000 and GEO0009.
September 2016: Field sheet notes described very low water levels at stations: PAT0176 and GUN0125; low at stations: MON0020, POT1472, POT1471, POT1596, POT1595 and SEN0008; and the lowest water level seen in a long time at station CON0180. Muddy water and upstream construction were observed at station JON0184. Submerged aquatic vegetation extended half way across the river at station GUN0125. A MD DNR Fishing and Boating Services team was sampling at the same time samples were collected at station POT1595. A lot of submerged aquatic vegetation was seen on the Maryland side during sampling at station POT1471. It rained upstream minutes before station CON0005 samples were collected. When station WIL0013 was sampled, Braddock Run waters were evident across Wills Creek. The waters at stations BDK0000 and NBP0461 were orange. Lots of submerged aquatic vegetation and fish were observed at station TOW0030. Secchi disk depth at station XGG8251 exceeded 0.6m.
October 2016: The flow rate at station CAC0031 was very low. Station WIL0013 samples were collected from the left side of the bridge in order to eliminate Braddock Run waters as much as possible. Lots of dust in the air, from trucks on the dirt road and parking lot, was noted when station NBP0534 samples were collected. Field sheet notes made when station SAV0000 was sampled, described a drain pipe installed directly into the river and algae (possibly didymo) covering sixty percent of the rocks. The Secchi disk measurement at station XGG8251 was greater than 1.1m.
November 2016: Lots of geese were present near the POT2386 sample collection site. Much leaf debris was observed in the station CON0180 sample area but the water seemed to be normal. The water at station CON0005 appeared to be normal and clear. At stations BCP0035, CAC0148, MON0269 and MON0528 the river was low and slow. Morning showers preceded sampling at stations: MON0020, POT1471, POT1472, POT1595, POT1596, SEN0008 and WIL0013. Braddock Run waters were evident when station WIL0013 was sampled. The river level was low when stations ANT0044 and POY1830 were sampled. Many leaves were observed in the creek when station ANT0082 was sampled. Filamentous algae were seen at station NBP0326 and the water was orange. The Secchi disk measurement at station XGG8251 exceeded station total depth. Leaf debris was present in the sample water collected at station NBP0326. Rain drizzle preceded sampling at stations: CJB0005, POT1184, PXt0972, RCM0111 and ANA0082.
December 2016: Rain fell the night before station TF1.0 was sampled. At stations PAT0176 and GUN0125 the rivers were low and slow. When station NPA0165 was sampled, sleet was falling, a new wire-weight auxiliary gage had been installed and culvert construction was taking place downstream. A station JON0184 field data sheet note stated that upstream restoration appeared to be complete and sleet fell during sampling.