Virginia Mainstem Water Quality Monitoring Stations

Metadata:

Identification_Information
Data_Quality_Information
Spatial_Data_Organization_Information
Spatial_Reference_Information
Entity_and_Attribute_Information
Distribution_Information
Metadata_Reference_Information

Identification_Information: top

Citation:

Citation_Information:

Originator: Old Dominion University

Originator: Water Quality Laboratory

Publication_Date: 20251030

Title: Virginia Mainstem Water Quality Monitoring Stations

Geospatial_Data_Presentation_Form: spatial database

Online_Linkage: <http://www.chesapeakebay.net>

Description:

Abstract:

Abstract: Virginia has 27 stations presently sampled semi-monthly for June through August, and monthly throughout the rest of the year for water quality monitoring.

Program started in June 1984 with bi-monthly cruises from March to October and monthly cruises from November to February. In 1988 due to budgetary constraints, one of the March cruises was eliminated. In 1989 due to budgetary constraints, one of the October cruises was eliminated. For 1989 through 1995, bi-monthly cruises were sampled from April to September and monthly cruises from October to March. In 1996 a monitoring refinement effort demonstrated that a reduction to fourteen cruises per year would allow sufficient power for detecting long-term trends, as well as accommodating concerns for living resource monitoring. The regimen adopted was bi-monthly sampling July and August with monthly sampling the remainder of the year.

In 2004 two additional mainstem cruises were added to the months of June and September, to enable a better assessment of the dissolved oxygen in the Chesapeake Bay. In 2005 only one mainstem cruise was collected in September in Virginia due to Hurricane Ophelia. In 2006 due to budgetary constraints, the cruise regimen was decreased to 14 cruises. No mainstem cruise was collected in February this year and two cruises per month were scheduled for June - August. In 2007 a second June cruise was added, so the Bay was sampled semi-monthly June- August, and monthly throughout the rest of the year. In 2008 due to budgetary constraints the cruise regimen was decreased to 14 cruises, sampled semi-monthly July- August, and monthly throughout the rest of the year. In 2010 the cruise regimen remained 14 cruises, but the semi-monthly sampling was changed to June and August, and July had one sampling cruise. In 2011 extra cruises were added during the year due to events which warranted increased monitoring. A second July cruise was added to obtain the physicochemical profiles at a subset of stations at the end of the month to collect more data for the low dissolved oxygen observed in the summer of 2011. To accommodate this change the first July cruise, which was originally scheduled for the week of July 18, was changed to the week of July 11, 2011. The second July cruise was collected the week of July 25, 2011. No nutrient, fluorometry or light/KD data was collected on the second July cruise. For ODU the Benthic laboratory was conducting their summer sampling on the Virginia portion of the Chesapeake Bay this week, so these profiles were completed on this cruise. The second August cruise was not collected due to damage in the Tidewater Virginia area caused by Hurricane Irene. The cruise was scheduled for August 29-31, and the hurricane came ashore in coastal Virginia the evening of August 27, 2011. A large amount of rain and flooding occurred due to Hurricane Irene and Tropical Storm Lee. A large sediment plume entered the Chesapeake Bay from the Susquehanna River in September 2011. An extra cruise was added to the beginning of October to collect more sampling data to document the effects of these storms. For ODU the cruise was scheduled for October 3-4, 2011 at 19 stations deemed most likely to show the storm effects. All normal parameters were collected at these stations. In addition phytoplankton samples and NOAA pathogen samples were collected at the normal designated stations. In 2012 15 cruises are scheduled, with two cruises per month in June, July and August. One cruise in July only physiochemical data will be collected to characterize the low dissolved oxygen present in the Chesapeake Bay. In 2013 15 cruises are scheduled, with two cruises per month in June, July and August. One cruise in July and one cruise in August only physiochemical data will be collected to characterize the low dissolved oxygen present in the Chesapeake Bay. The nutrient collections for the second August 2013 cruise were eliminated due to funding issues. In 2014 14 cruises are scheduled, with two cruises per month in June, July and August. One cruise in June and one cruise in July only physiochemical data will be collected to characterize the low dissolved oxygen present in the Chesapeake Bay. The January 2014 mainstem water quality cruise and the nutrient collections for the second June 2014 cruise were eliminated due to funding issues. Starting in 2015 15 cruises are scheduled, with two cruises per month in June, July and August. One cruise in July only physiochemical data will be collected to characterize the low dissolved oxygen present in the Chesapeake Bay. In 2022 the November cruise was not sampled. The R/V Slover Captain had emergency surgery and a backup boat could not be obtained on short notice. Tentatively scheduled a small boat to sample some stations and filter in the laboratory, but weather conditions made this plan unsafe.

The following changes in monitoring occurred in 2020 and 2021 due to Covid-19 protocols. Old Dominion University (ODU) Water Quality Laboratory (WQL) did not sample the Virginia portion of the Chesapeake Bay in March and April of 2020. In May 2020 the ODU Office of Research granted the WQL permission to sample, but only 3 individuals were allowed on the Research Vessel. This included 2 research vessel crew members and one WQL scientist. The ODU R/V Fay Slover was unavailable due to repairs, so the Virginia Institute of Marine Science (VIMS) R/V Tidewater was used for May through July 2020. The R/V Tidewater does not have an underway system for the horizontal fluorometry. Due to only one WQL scientist aboard the research vessel, modifications to sample collection needed to be made. These modifications were used for May, June and July sampling in 2020. The Licor (LIGHT/KD) was not collected. The physiochemical profile data was collected on the YSI EXO data logger, but it was not written down on station. Pycnoclines could not be calculated in the field without the handwritten data, so no pycnocline samples were collected. Phytoplankton composite samples were collected at 1/3 and 2/3 of the water column instead of above and below the pycnocline. Whole water samples were collected in the field and kept on ice. Each evening a technician met the research vessel and transported the whole water samples back to the laboratory for the samples to be filtered the next day. For June and July 2020 only one cruise was collected due to decreased laboratory and field capacity due to Covid-19 protocols and the unavailability of the R/V Fay Slover.

Starting with the August 2020 cruises the ODU Office of Research granted the WQL permission to have two WQL scientists aboard the research vessel. The R/V Fay Slover is now available. Due to only two WQL scientists aboard the research vessel, modifications to sample collection needed to be made. These modifications were in effect until May 2021 when three WQL scientists were allowed on the research vessel. Pycnocline samples were not collected at stations CB6.2, CB6.3 and CB7.3. Replicate samples were not collected at station CB7.4N. An additional field split sample was collected to replace the replicate samples. All filtering was done in the field except for some particulate carbon/particulate nitrogen (PC/PN) samples where there was not enough time to filter. The PC/PN samples were brought back to the laboratory for filtration, and it was noted which samples/stations were affected. In December 2020 due to weather and research vessel problems no cruise was collected.

Starting in May 2021 the WQL went back to the normal sampling regime with the ODU Office of Research allowing 3 Water Quality Scientists on board the research vessel. This includes collecting pycnocline samples at all 8 stations, two replicate samples are collected at a random station and all samples are filtered in the field if conditions allow. Field Splits are collected at two random stations for dissolved nutrients and one station for DOC on cruises where DOC samples and living resources are collected.

The program was established as a long-term program of data collection and analysis to

establish baseline water quality conditions in the Bay and to monitor changes in water quality

conditions over time. Stations were located to characterize the salinity and circulation regimes

found in the Virginia portion of the Chesapeake Bay and to determine environmental conditions

associated with intensive urbanization in the lower Bay proper.

The program began in June, 1984 with the collecting organizations in Virginia and Maryland coordinating the sampling times of their stations on the mainstem Bay, so that data for each sampling event represents a synoptic picture of the main bay at that point in time. For 1984 through 1995, Old Dominion University (ODU) collected 8 Virginia mainstem samples. The station ID's were: LE5.5, CB8.1, CB8.1E, CB7.4, CB7.4N, CB7.3, CB7.3E and CB6.4. The remaining Virginia stations were collected by the Virginia Institute of Marine Science (VIMS). Starting in 1996 to present, ODU collects all 27 Virginia mainstem BAY stations. In 1994 as part of the Tributary Enhancement Program, ODU monitored 2 additional stations at the mouth of the James River. These stations ID's were LE5.5A and LE5.5B, only surface samples were collected for nutrient analysis and these two stations were only monitored for the year of 1994. In September 1996 station LE5.5 was relocated to approximately 0.6 miles west of the original station location. This station is called LE5.5-W. In December 2002 no samples were collected for this program due to weather and boat mechanical problems. Starting in July 2024 a new deep- water station was added called CB7.3N. This station was added to measure hypoxic volume in section CB7PH. It will be sampled seven times a year, twice monthly sampling in June through August and monthly sampling in September. Only physicochemical profile data will be collected at select depths. Station information and Secchi will be recorded. No light data or water samples will be collected at this station.

The sampling frequency has changed over time, and some stations have been deleted or added. Parameters sampled include: temperature (WTEMP), dissolved oxygen (DO), specific conductivity (SPCOND), salinity (SALINITY), pH (pH), secchi depth (SECCHI), chlorophyll a (CHLA), pheophytin (PHEO), filtered silica(SIF), total suspended solids (TSS), fixed suspended solids (FSS), total phosphorus (TP), total dissolved phosphorus (TDP), particulate phosphorus (PP), orthophosphate filtered (PO4F), total dissolved nitrogen (TDN), total Kjeldahl nitrogen whole and filtered (TKNW, TKNF), nitrite plus nitrate filtered (NO23F), nitrite filtered (NO2F), nitrate filtered (NO3F), ammonium filtered (NH4F), particulate nitrogen (PN), total organic carbon (TOC), dissolved organic carbon (DOC), particulate carbon (PC), colored dissolved organic matter (CDOM) . Some parameters have been dropped or replaced over time.

See the station listing at www.chesapeakebay.net/data/index.htm

Purpose:

This database was created to store grant deliverable data collected as part of the Chesapeake Bay Program water quality monitoring program.

Long term monitoring of water quality trends in the Virginia portion of the Chesapeake Bay. These data are used to guide environmental decisions and to monitor responses of the system to management actions.

Time_Period_of_Content:

Time_Period_Information:

Range_of_Dates/Times:

Beginning_Date: 19840601

Ending_Date: 20250831

Currentness_Reference: Ground Condition

Status:

Progress: In work

Maintenance_and_Update_Frequency: As needed

Spatial_Domain:

Bounding_Coordinates:

West_Bounding_Coordinate: -76.5

East_Bounding_Coordinate: -75.700000000000003

North_Bounding_Coordinate: 38.0

South_Bounding_Coordinate: 36.799999999999997

Keywords:

Theme:

Theme_Keyword_Thesaurus: CIMS Subject Keyword List

Place:

Place_Keyword_Thesaurus: User Defined Keyword List

Place_Keyword: Chesapeake

Place_Keyword: Chesapeake Bay

Place_Keyword: Monitoring Segment

Place_Keyword: Virginia

Access_Constraints: None

Use_Constraints: None

Data_Quality_Information: top

Attribute_Accuracy:

Attribute_Accuracy_Report:

All data generated by the laboratory is subjected to QA/QC protocol and peer review. Instrument maintenance is performed and recorded in instrument manuals.

Quality assurance data for chemical analyses measure two quantities, precision and accuracy. Precision is the repeatability of measurements, and accuracy is the closeness of analytical measurement to a ''true'' value. CBP QA data include precision and accuracy comparisons within the same organization, and among results from different organizations.

Within-organization QA data:

Samples are spiked and replicated at a frequency of at least 20%. The spike recoveries must be within 80-120%, and the replicates must be ≤20% RPD or ≤ PQL for dissolved and ≤30% RPD or ≤PQL for particulates. Calibration curves are analyzed and the r>= 0.9980. Calibration standards are analyzed every 10-20 samples to ensure analysis is in calibration. CRMs are analyzed for parameters they are commercially available for. For the following analysis CRMs are analyzed with each calibration curve: NO23F, NH4F, TDN, TDP, PP, PO4F, DOC, PC and PN. For SIF a stock standard is purchased, and a second stock standard or CRM is used to confirm the calibration curve. For NO2F, the stock standard is made and a second purchased stock standard is used to confirm the calibration. The YSI EXO2 sonde used to collect physiochemical parameters DEPTH, COND (SALINITY), PH, WTEMP, and DO is calibrated before every sampling event and post-calibrated after each sampling event. The spectrophotometer used for CHLA/PHEO analysis is checked monthly with NIST standards. The balances used in the laboratory are checked monthly with Class 1 standard weights. Laboratory replicate and spike data are submitted to CBP. At some stations, field replicates or field splits are also generated, and these are reported and included within the water quality database.

Field QA Data:

Field precision is estimated with field replicates and splits.

Field replicates:

Old Dominion University collects true field replicate samples (separate grabs) at a specified station (first CB7.3 and currently CB7.4N) and includes these as individual observations in both its monitoring and QA data submissions. SAMPLE_ID for these monitoring data will have values of ''S1'' or ''S2''.

Starting in May 2008, Old Dominion University collects two field splits at random stations and depths and include these as individual observations in both its monitoring and QA data submissions. SAMPLE_ID for these monitoring data will have values of ''FS1'' or ''FS2''.

Inter-organization QA data:

In Virginia, VIMS and ODU exchanged field split samples from 1985 through 1989; these results were analyzed in Bergstrom (1989), ''Split sample water quality results from laboratories participating in the Chesapeake Bay Program: 1985-1989''.

The Coordinated Split Sample Program (CSSP) was organized to include all the laboratories in the CBP. Mainstem laboratories have analyzed split samples quarterly since June 1988, sending mainstem samples to the three mainstem laboratories, Chesapeake Biological Laboratory (CBL), VIMS, and ODU, as well as the two main tributary laboratories, Maryland Dept of Health and Mental Hygiene, (DHMH), and Virginia Division of Consolidated Laboratory Services (DCLS). Over time the CSSP has grown to include three components (mainstem, tributary, and fall line) each including three to five labs that analyze samples from similar salinity regimes and concentration ranges. The fall line has since been eliminated, and those laboratories now participate in the tributary split program.

ODU participates in the mainstem and tributary CSSP. For the tributary component labs analyze triplicate field samples that are collected quarterly. For the mainstem component the sample design was identical to the tributary component until 1999. Starting in 1999 labs analyze quadruplicate field samples that are collected quarterly. Two of the samples are analyzed for each parameter, and the other two samples are analyzed on a separate analysis day (or time for analyses such as TSS) for each parameter. Starting in May 2007 if it creates hardship to spilt the mainstem samples into two analysis days they may be run on the same day. This change was approved by AMQAW, now known as DIW (Data Integrity Workgroup).

The data are analyzed at the CBP and reported to the Data Integrity Workgroup (DIW). The goal is to identify parameters that have low inter-laboratory agreement, estimate the measurement system variability, and then take action to increase the level of agreement. These data are not included in the water quality database.

Another aspect of quality assurance is detection limits. The minimum detection limit (MDL) is the lowest concentration of a parameter that the measurement system can detect reliably. At participating laboratories, the MDL is currently determined from the students’t times the standard deviation of a minimum of seven replicates. Starting in 2018 for dissolved parameters the most recent version of the EPA Definition and Procedure for the Determination of the Method Detection Limit will be used. For particulate parameters a minimum of 7 low level samples are used. The MDL determination is analyzed on multiple dates or times. NOTE: Prior to 2011 the MDL was determined from three times the standard deviation of seven replicates of a low-level ambient water sample. Prior to 2013 the MDL sample was analyzed all in the same day. Prior to 2017 used low level samples to calculate MDLs for all parameters. Starting in 2017 low level standards are used to calculate MDLs for dissolved parameters. In the Chesapeake Bay Program (CBP) database, when measurements are below the MDL, the value of the parameter is set to the detection limit and the associated detection limit field, QUALIFIER, is set to ''<''. Detection limits for many parameters have generally been lowered over the life of the program. These detection limits are submitted by ODU to the CBP database on a yearly basis.

Logical_Consistency_Report: None.

Completeness_Report:

When the monitoring program began in June, 1984, there were 20 cruises scheduled for the VA mainstem - one each in Nov, Dec, Jan, Feb, and two each in all other months. Through time, changes in number of cruises per year for VA have occurred. 1984-1987 20 cruises per year. 1988 19 cruises per year, the second March cruise is dropped. 1989-1995 18 cruises, the second October cruise is dropped. 1996-2003 14 cruises, the second cruise in April, May, June and September are dropped. 2004 - 2005 16 cruises, a second cruise is added to June and September. 2006 14 cruises, no cruise in February and a second cruise in June through August. 2007 15 cruises, two cruises a month June through August. 2008-2009 14 cruises, one cruise a month except two cruises a month for July and August. Starting in 2010 14 cruises, one cruise a month except two cruises a month for June and August. Starting in 2011 a second July cruise has been added to collect physicochemical profile data to help capture the low dissolved oxygen values seen in the summer. Starting in 2013 the second August cruise was changed to only collecting the physicochemical profile. In 2014 the January cruise was eliminated, the second June cruise was changed to only collecting the physicochemical profile, and the second August cruise was a full cruise with nutrient water collection. In 2015 the January cruise was reinstated for a total of 15 cruises. Two cruises a month are collected June, July and August and one cruise is collected September through May. The second July cruise only the physicochemical profile is collected.

In addition, some stations may not be sampled at times depending on weather or other anomalies. This information is documented in the WQ_CRUISE table COMMENTS field.

For the period June, 1984 through August, 1998 data from the monitoring program were stored in SAS data sets at the CBP computer center. When the ACCESS format came into use as the submittal format, information normally contained in the data set documentation file was stored within the data tables or in COMMENTS fields. As time permits the cruise, station, and parameter documentation for the old data will be moved to the appropriate ACCESS tables. Refer to DIW, ''Guide to Using Chesapeake Bay Program Water Quality Monitoring Data'', www.chesapeakebay.net/data/index.htm

Values that are missing have a code in the PROBLEM column in tables that it is available. If there is not a PROBLEM code in the table it is listed in the COMMENT section of the table.

Positional_Accuracy:

Horizontal_Positional_Accuracy:

Horizontal_Positional_Accuracy_Report: A GPS using NAD83 is used on the boat to find station location.

Vertical_Positional_Accuracy:

Vertical_Positional_Accuracy_Report: A GPS using NAD83 is used on the boat to find station location.

Lineage:

Process_Step:

Process_Description:

Samples are collected on 27 fixed stations 14 times a year. Presently, for the SIF, NO23F, NO2F, NH4F, PO4F, TDN, TDP and PP analysis, a Lachat® Flow Injection Analyzer is used. Starting in December 2023 a Seal® AutoAnalyzer 500 will be used in conjunction with the Lachat® Flow Injection Analyzer. It will be noted in the individual parameters which instrument was used. For PC/PN analysis a CE Instruments Flash EA 1112 Elemental analyzer is used. For DOC a Shimadzu® Total Organic Carbon Analyzer Model TOC-L is used. For field parameters SPCOND, SALINITY,DO, PH, WTEMP, and DEPTH, a YSI EXO2 with an optical DO probe is used. For CHLA and PHEO a Shimadzu UV-2401 PC dual beam spectrophotometer is used. In WQ_DATA table, all data with SAMPLE_TYPE D is downloaded directly from instruments and entered into the database, except CHLA, PHEO, FSS and TSS which are calculated in ACCESS. The raw OD values for CHLA and PHEO and the weights for TSS and FSS are downloaded directly from the instruments into an Access database. For this data the volume filtered, the volume extracted (for CHLA and PHEO) and the light path (for CHLA and PHEO) are hand entered and visually inspected. For the WQ_DATA table the SECCHI data are double entered and compared in Access. For the WQ_DATA table all data with SAMPLE_TYPE ISM, except the SECCHI data, are downloaded directly from the YSI data logger and imported into the Access database. If a depth is not saved in the YSI data logger file the data is hand entered and visually inspected, and a note is placed in the comment section of the WQ_DATA table. For the WQ_EVENT table all data are double entered and compared in Access. For the WQ_KD table the instrument values are downloaded and imported into the Access database, and the station and depths are hand entered and visually inspected.

The methods are found in the METHOD column, which corresponds to a method code. The methods used by this laboratory through the years are as follows:

PARAMETER NAME: BIOSI, particulate biogenic silica

CBP METHOD: L01

EPA METHOD OR OTHER DESCRIPTION: Particulates collected on a 0.4 um polycarbonate filter undergo a mild digestion using 0.2 N NAOH. Silicon is analyzed colorimetrically using an automated silicomolybdate method at a wave length of 660 or 810 nm.

REFERENCE: Technicon Industrial Method No.186-72W, Silicates in Water and Seawater, (1973).

ODU only analyzed this parameter in 1994 as part of the CBP Manistem Enhancement program. Samples were analyzed for the following cruises: BAY194 (March), BAY198 (May), BAY200 (June), BAY202 (July), BAY204 (August) and BAY208 (October). They were analyzed on a Skalar continuous flow analyzer.

PARAMETER NAME: CHLA, chlorophyll a, monochromatic, spectrophotometric

CBP METHOD: L01

EPA METHOD OR OTHER DESCRIPTION: APHA – 10200H.

REFERENCE: APHA, 1995. Standard Methods, 19th edition, Method 10200H.

Perkin Elmer dual beam spectrophotometer used until December 1997. January 1998-December 2005 a Unicam UV1 dual beam spectrophotometer is used. January 2006-present a Shimadzu 2401PC dual beam spectrophotometer is used.

PARAMETER NAME: CDOM_440 and CDOM_SLOPE, colored dissolved organic matter, spectrophotometric

CBP METHOD: L01

EPA METHOD OR OTHER DESCRIPTION:

REFERENCE: Mitchell B.G., Bricaud A., Carder K., Cleveland J., et al., 2000, Determination of spectral absorption coefficients of particles, dissolved material and phytoplankton for discrete water samples, [in:] Ocean Optics Protocols for Satellite Ocean Color Sensor Validation. Revision 2, G. S. Fargion & J.L.Mueller (eds.), NASA/TM2000209966, Greenbelt, Maryland, Goddard Space Flight Centre, 125153.

Analysis conducted in July 2005-October 2005 and April 2006-June 2006 using a Shimadzu UV-2401 PC dual beam UV/VIS Recording spectrophotometer. The data was calculated using an Excel® spreadsheet developed by the Smithsonian Environmental Research Center, and is reported using the parameter names CDOM_440 and CDOM_SLOPE.

PARAMETER NAME: SPCOND, conductivity, in-situ specific conductance at 25 C

CBP METHOD: F01

EPA METHOD OR OTHER DESCRIPTION: A calibrated conductivity sensor attached to a multi-probe sonde is lowered into a water body and allowed to stabilize prior to taking the meter reading.

REFERENCE:

ODU used an RS-5 salinometer from 1984 to April, 1986. ODU used a Hyrolob Sonde unit II from May, 1986 to February, 1997. ODU using a YSI 6000 from March, 1997 to March, 2008. ODU using a YSI 6600 V2 from April, 2008 to October 2014. Purchased a YSI 6600 V2 and started using in April 2007. Doing a comparison study between this YSI and previous YSI. Did not submit this YSI data until instructed by VA DEQ, unless a problem with old YSI. On April 19, 2007 had to submit this data because old YSI was sent back to manufacturer for repairs. Beginning in November 2014 started using a YSI EXO2 sonde and handhelds.

PARAMETER NAME: DO, dissolved oxygen, in-situ membrane electrode

CBP METHOD: F01 for Clark Cell Do probe. F04 for optical DO probe.

EPA METHOD OR OTHER DESCRIPTION: APHA - 4500-O G

REFERENCE: APHA. Standard Methods, 18th Edition.

ODU used an RS-5 salinometer from 1984 to April, 1986. ODU used a Hyrolob Sonde unit II from May, 1986 to February, 1997. ODU using a YSI 6000 from March, 1997 to March, 2008. ODU using a YSI 6600 V2 with an optical DO probe from April, 2008 to October 2014. Purchased a YSI 6600 V2 and started using in April 2007. Doing a comparison study between this YSI and previous YSI. Did not submit this YSI data until instructed by VA DEQ, unless a problem with old YSI. On April 19, 2007 had to submit this data because old YSI was sent back to manufacturer for repairs. Beginning in November 2014 started using a YSI EXO2 sonde and handhelds.

PARAMETER NAME: DOC, dissolved organic carbon, wet oxidation method

CBP METHOD: L02

EPA METHOD OR OTHER DESCRIPTION: APHA - 5310 D

REFERENCE: APHA, 1986. Standard Methods, 19th Edition Supplement. Method 5310 D.

ODU analyzed this parameter from 1984-1995. It was dropped as a parameter for the mainstem BAY by the EPA beginning in 1996.

PARAMETER NAME: DOC, dissolved organic carbon

CBP METHOD: L01

EPA METHOD OR OTHER DESCRIPTION: EPA Method No. 415.1. APHA - 5310B.

REFERENCE: Combustion Infrared Method. EPA Method No. 415.1. USEPA. EPA. 1983. METHODS FOR CHEMICAL ANALYSIS OF WATER AND WASTES. USEPA-600/4-79-020. METHOD 415.1; PP. 415.1/1-3. AMERICAN PUBLIC HEALTH ASSOCIATION. 1995. STANDARD METHODS FOR EXAMINATION OF WATER AND WASTEWATER; 19TH EDITION. METHOD 5310 B.

FILTERED SAMPLES (0.7 um FILTER) ARE PURGED WITH AIR UNDER ACIDIC CONDITIONS TO REMOVE INORGANIC CARBON. THE ORGANIC CARBON IS CONVERTED TO CARBON DIOXIDE BY CATALYTIC COMBUSTION. THE CARBON DIOXIDE FORMED IS MEASURED DIRECTLY BY AN INFRARED DETECTOR.

Started analyzing this parameter at surface only at living resources stations CB6.1, CB6.4, CB7.3, CB7.4, LE5.5-W, WE4.2 and LE3.6 in January 2007. Will only collect when living resource samples are collected. ODU used a Shimadzu Corporation TOC-5000 from January 2007 to September 2016. Starting in October 2016 a Shimadzu Corporation TOC-LCSH used.

PARAMETER NAME: EPAR_S, epar at surface

CBP METHOD: F01

EPA METHOD OR OTHER DESCRIPTION: Reference measurement for incident radiation at surface of the water. Photosynthetically active radiation (PAR) is measured in air using a flat cosine quantum light sensor (Li-cor, LI-190SA/ LI-190R or equivalent) pointed upwards. Units are micromoles per second per square meter, which equal microeinsteins. One EPAR_S value is taken as close as possible in time to each underwater value collected.

REFERENCE:

ODU started analyzing this parameter in the mainstem BAY with the BAY176 (April 13, 1993) cruise.

PARAMETER NAME: EPARD_Z, in-situ, downwelling par

CBP METHOD: F01

EPA METHOD OR OTHER DESCRIPTION: Photosynthetically active radiation (PAR) is measured underwater using a flat cosine quantum sensor (Li-cor LI-190SA/LI-192 or equivalent) pointing down in the water column. An initial underwater light reading is taken at 1.0 meter depth, then at 1.0 meter increments until the bottom or if the value is <1 m/m**2/s with the underwater upwelling probe before reaching bottom the light profile is terminated.

REFERENCE:

ODU started analyzing this parameter in the mainstem BAY with the BAY176 (April 13, 1993) cruise. ODU stopped taking this parameter with the BAY295 (March, 1999) cruise with the approval of the CBP subcommittees.

PARAMETER NAME: EPARU_Z, in-situ, upwelling par

CBP METHOD: F01

EPA METHOD OR OTHER DESCRIPTION: Photosynthetically active radiation (PAR) is measured underwater using a flat cosine quantum sensor (Li-cor LI-190SA/li-192 or equivalent) pointing up in the water column. An initial underwater light reading is taken at 0.5 meters starting in June, 2003 (previously the initial reading had been collected at the 1.0 meter depth. Starting in June 2004, the depths for which light data is collected is determined by water clarity as measured by the secchi depth. (Previously light was collected at 1.0 meter increments until the bottom or if the value is <1 m/m**2/s with the underwater upwelling probe before reaching bottom the light profile is terminated. If the light is not <1 m/m**2/s before reaching 15 meters, than the light is collected in 2 meter intervals.)

REFERENCE:

ODU started analyzing this parameter in the mainstem BAY with the BAY176 (April 13, 1993) cruise.

PARAMETER NAME: FSS, fixed suspended solids

CBP METHOD: L01

EPA METHOD OR OTHER DESCRIPTION: APHA – 2540 E.

REFERENCE: APHA. 1989. Method: 2540 E. Fixed and Volatile Solids Ignited at 550°C. Standard Methods for the Examination of Water and Wastewater. American Public Health Association, American Water Works Association, and Water Pollution Control Federation. Washington, D.C. 17th Edition. 1989

ODU only analyzed this parameter in 1994 as part of the CBP Mainstem Enhancement program. Samples were analyzed for the following cruises: BAY194 (March), BAY198 (May), BAY200 (June), BAY202 (July), BAY204 (August) and BAY208 (October).

In January 2002 this parameter was added to the Virginia mainstem Chesapeake Bay Program at all stations.

FSS data was not submitted for BAY 463 collected July 24-26, 2007.

FSS data was not submitted for BAY 543 collected December 17, 2010. The muffle furnace broke while processing these samples. A new furnace was purchased and used starting with the January 2011 samples.

PARAMETER NAME: NH4F, ammonia nitrogen, (filtered), colorimetric, automated phenate (indophenol)

CBP METHOD: L01

EPA METHOD OR OTHER DESCRIPTION: 350.1

REFERENCE: A. EPA, 1983. USEPA-600/4-79-020. Method 350.1.

B. EPA, 1993. EPA/600/R-93/100. Method 350.1, Rev 2.

ODU used a Scientific Instruments Corporation autoanalyzer from 1984 to April, 1997. In May, 1997 switched to a Skalar continuous flow analyzer. In July, 2014 switched to a Lachat flow injection analyzer. In March 2024 switched to a Seal AutoAnalyzer 500. Both instruments could be used in the laboratory starting in December 2024 for this analysis.

In July 2008, the buffer solution used in this analysis was changed. The buffer solution for the ammonia analysis included both sodium potassium tartrate tetrahydrate and sodium citrate. The buffer is present for the prevention of precipitation due to salts. It was discovered sodium potassium tartrate tetrahydrate was a source of contamination in numerous ammonia analyses. The chemical was ordered from four vendors, all with the same result. When the analysis was run without the sodium potassium tartrate no precipitation was noted and, therefore, is not necessary. The ODU WQL will eliminate sodium potassium tartrate tetrahydrate from the ammonia buffer solution unless precipitation is noted, at which time it will be required. In July 2014 when switched to the Lachat flow injection analyzer, this chemical was added back into the buffer reagent. In January 2022 problem with sodium potassium tartrate tetrahydrate occurred again. Was removed from buffer reagent. For SEAL, EDTA is used in the buffer reagent/complexing reagent so this should not be an issue in the future.

PARAMETER NAME: NO23F, nitrite plus nitrate nitrogen (filtered), colorimetric, automated cadmium reduction.

CBP METHOD: L01

EPA METHOD OR OTHER DESCRIPTION: 353.2

REFERENCE: A. EPA, 1983. USEPA-600/4-79-020. Method 353.2.

B. EPA, 1993. EPA/600/R-93/100. Method 353.2, Rev 2.

ODU used a Scientific Instruments Corporation autoanalyzer from 1984 to December, 1995. In January, 1996 switched to a Skalar continuous flow analyzer. In July, 2014 switched to a Lachat flow injection analyzer. In March 2024 switched to a Seal AutoAnalyzer 500.

PARAMETER NAME: NO2F, nitrite nitrogen (filtered), automated, colorimetric, diazotization

CBP METHOD: L01

EPA METHOD OR OTHER DESCRIPTION: 353.2

REFERENCE: EPA, 1983. USEPA-600/4-79-020. Method 353.2.

ODU started using this method in July, 1997 with a Skalar continuous flow analyzer. In July, 2014 switched to a Lachat flow injection analyzer. In December 2023 switched to a Seal AutoAnalyzer 500.

PARAMETER NAME: NO2F, nitrite nitrogen (filtered), manual, colorimetric, diazotization

CBP METHOD:

EPA METHOD OR OTHER DESCRIPTION: APHA Method No. 413 B.

REFERENCE: APHA 1985. Standard Methods for Examination of Water and Wastewater. 16th ed., American Public Health Association, Washington, D.C.

ODU used this or the 15th ed. method from 1984 to June, 1997.

PARAMETER NAME: PC, particulate carbon

CBP METHOD: L01

EPA METHOD OR OTHER DESCRIPTION: 440.0

REFERENCE: Methods for the Determination of Chemical Substances in Marine and Estuarine Matrices. 2nd Edition, 1997. Method 440.0.

ODU started analyzing this method in January, 1988. ODU used a Carlo Erba N/A 1500 from 1988 until April 30, 2001.

Starting May 1, 2001 ODU is using a CE Instruments Flash EA 1112 Elemental Analyzer. A method comparison study between this new instrument and the Carlo Erba NA 1500 was completed. The results are reported in A Comparison of Two Instruments for the Determination of Particulate Carbon and Particulate Nitrogen Concentrations in Estuarine Water Samples.

PARAMETER NAME: PH, in-situ electrode method

CBP METHOD: F01

EPA METHOD OR OTHER DESCRIPTION: 150.1, A calibrated pH electrode, (corrects for temperature) attached to a multi-probe sonde, is lowered into a water body and allowed to stabilize prior to taking the meter reading.

REFERENCE: EPA, 1983. USEPA-600/4-79-020. Method 150.1.

PARAMETER NAME: PH, electrode method

CBP METHOD: F02

EPA METHOD OR OTHER DESCRIPTION: 150.1, A grab sample is collected and measured in the field using a portable PH meter (temperature corrected).

REFERENCE: EPA, 1983. USEPA-600/4-79-020. Method 150.1.

ODU used this method from 1984-April, 1986. Only report pH for surface and bottom and pycnocline samples where applicable.

PARAMETER NAME: PHEO, monochromatic, spectrophotometric

CBP METHOD: L01

EPA METHOD OR OTHER DESCRIPTION: APHA - 10200 H

REFERENCE: APHA, 1995. Standard Methods, 19th Edition, Method 10200 H.

PARAMETER NAME: PIP, particulate inorganic phosphorus, semi-automated, direct

CBP METHOD: L01

EPA METHOD OR OTHER DESCRIPTION: Particulates on a 0.7um glass fiber filter are dried at 104C. Phosphate is extracted with HCL and measured by the automated ascorbic acid method for PO4.

REFERENCE: Aspila, Agemian and Chau, 1976. ''A Semi-automated

Method for the Determination of Inorganic, organic and Total Phosphate in Sediments'', Analyst 101:187-197.

PARAMETER NAME: PN, particulate nitrogen

CBP METHOD: L01

EPA METHOD OR OTHER DESCRIPTION: 440.0

REFERENCE: Methods for the Determination of Chemical Substances in Marine and Estuarine Matrices. 2nd Edition, 1997. Method 440.0.

ODU started analyzing this method in January, 1988. ODU used a Carlo Erba N/A 1500 from 1988 until April 30, 2001.

PARAMETER NAME: PO4F, orthophosphate, (filtered), automated, ascorbic acid

CBP METHOD: L01

EPA METHOD OR OTHER DESCRIPTION: 365.1

REFERENCE: EPA, 1983. USEPA-600/4-79-020. Method 365.1.

EPA, 1993. EPA/600/R-93/100. Method 365.1, Rev 2.

ODU started using this method in May, 1997 on the Skalar continuous analyzer. In July, 2014 switched to a Lachat flow injection analyzer. In December 2023 switched to a Seal AutoAnalyzer 500.

PARAMETER NAME: PO4F, orthophosphate, (filtered), manual, ascorbic acid

CBP METHOD:

EPA METHOD OR OTHER DESCRIPTION: 365.3

REFERENCE: EPA, 1983. USEPA-600/4-79-020. Method 365.3.

ODU used this method from 1984 to April, 1987.

PARAMETER NAME: PP, particulate phosphorus, semi-automated, direct

CBP METHOD: L01

EPA METHOD OR OTHER DESCRIPTION: Particulates on a 0.7um glass fiber filter are weighed, then combusted @ 550C to convert organically bound phosphorus to phosphate. Phosphate is extracted with HCL and measured by the automated ascorbic acid method for PO4.

REFERENCE: Aspila, Agemian and Chau, 1976. ''A Semi-automated Method for the Determination of Inorganic, organic and Total Phosphate in Sediments'', Analyst 101:187-197.

ODU started to analyze this parameter in January, 1988. ODU used a Scientific Instruments Corporation autoanalyzer from 1988 to December, 1995. In January, 1996 switched to a Skalar continuous flow analyzer. In July, 2014 switched to a Lachat flow injection analyzer. In April 2024 switched to a Seal AutoAnalyzer 500. Started having peak shape problems with the Seal PP method and switched back to the Lachat flow injection analyzer starting with the second August BAY 871 cruise while the method problems are corrected.

PARAMETER NAME: SALINITY, in-situ measurement

CBP METHOD: L01

EPA METHOD OR OTHER DESCRIPTION: In-situ measurement with probe

REFERENCE:

PARAMETER NAME: SECCHI, 20 cm secchi disk

CBP METHOD: F01

EPA METHOD OR OTHER DESCRIPTION: A 20 cm diameter secchi disk is lowered into the water and the depth (in meters) at which the black and white quadrants can no longer be distinguished is averaged with the depth at which the black and white quadrants can again be distinguished.

REFERENCE: Tyler, John. 1968. The Secchi Disk, Limnology and Oceanography, 13(1):1-6.

PARAMETER NAME: SIF, silica as SI, (filtered), colorimetric, automated, molybdenum blue

CBP METHOD: L01

EPA METHOD OR OTHER DESCRIPTION: 366.0

REFERENCE: Methods for the Determination of Chemical Substances in Marine and Estuarine Matrices - 2nd Edition, 1997. Method 366.0 “Determination of Dissolved Silicate in Estuarine and Coastal Waters by Gas Segmented Continuous Flow Colorimetric Analysis.”

PARAMETER NAME: TDN, total dissolved nitrogen, alkaline persulfate wet oxidation + EPA 353.2

CBP METHOD: L01

EPA METHOD OR OTHER DESCRIPTION: Pre-filtered samples are run through an alkaline persulfate wet oxidation to change all N-containing compounds into nitrate. Nitrate concentration is determined using an auto analyzer equipped with a cadmium reduction column.

REFERENCE: D’Elia, C.F., P.A. Steudler and N. Corwin, 1977. “Determination of Total Nitrogen in Aqueous Samples using Persulfate Digestion.” Limnology and Oceanography, 22:760-764

APHA. 1995. Method: 4500-N_org.D. Nitrogen. Persulfate Method. Standard Methods for the Examination of Water and Wastewater. American Public Health Association, American Water Works Association, and Water Pollution Control Federation. Washington, D.C. 19th Edition. 1995.

PARAMETER NAME: TDP, total dissolved phosphorus, alkaline persulfate wet oxidation + EPA 365.1

CBP METHOD: L01

EPA METHOD OR OTHER DESCRIPTION: Filtered samples are run through an alkaline persulfate wet oxidation, which turns acidic and changes all P-containing compounds into phosphate. Phosphorus is measured as PO4 using EPA 365.1, an automated spectrophotometric method.

REFERENCE: EPA, 1993. EPA/600/R-93/100. Method 365.1, Rev 2.

D’Elia, C.F., P.A. Steudler and N. Corwin, 1977. “Determination of Total Nitrogen in Aqueous Samples using Persulfate Digestion.” Limnology and Oceanography, 22: 760-764

APHA. 1995. Method: 4500-P F. Automated Ascorbic Acid Reduction Method. Standard Methods for the Examination of Water and Wastewater. American Public Health Association, American Water Works Association, and Water Pollution Control Federation. Washington, D.C. 19th Edition. 1995.

ODU started using this method in July, 1997 on the Skalar continuous flow analyzer. In July, 2014 switched to a Lachat flow injection analyzer.

PARAMETER NAME: TDP, total dissolved phosphorus, colorimetric, manual, ascorbic acid

CBP METHOD:

EPA METHOD OR OTHER DESCRIPTION: 365.3

REFERENCE: EPA, 1983. USEPA-600/4-79-020. Method 365.3

ODU used this method from 1984 to June, 1997.

PARAMETER NAME: TKNF, total Kjeldahl nitrogen (filtered), semi-automated block digestor, colorimetric, nitroprusside

CBP METHOD: L02

EPA METHOD OR OTHER DESCRIPTION: 351.2

REFERENCE: EPA, 1983. USEPA-600/4-79-002. Method 351.2.

ODU used this method until December, 1987. This parameter has not been analyzed for the mainstem Bay since December, 1987.

PARAMETER NAME: TKNW, total Kjeldahl nitrogen (whole), semi-automated block digestor, colorimetric, nitro

CBP METHOD: L02

EPA METHOD OR OTHER DESCRIPTION: 351.2

REFERENCE: EPA, 1983. USEPA-600/4-79-002. Method 351.2.

ODU used this method until December, 1987. This parameter has not been analyzed for the mainstem Bay since December, 1987.

PARAMETER NAME: TOC, total organic carbon, wet oxidation

CBP METHOD: L02

EPA METHOD OR OTHER DESCRIPTION: APHA - 5310 D

REFERENCE: APHA, 1996. Standard Methods, 19th Edition Supplement, Method 5310 D.

ODU used this method until December, 1987. This parameter has not been analyzed for the mainstem Bay since December, 1987.

PARAMETER NAME: TP, total phosphorus, colorimetric, manual, ascorbic acid

CBP METHOD:

EPA METHOD OR OTHER DESCRIPTION: 365.3

REFERENCE: EPA, 1983. USEPA-600/4-79-020. Method 365.3.

ODU used this method until December, 1987. This parameter has not been analyzed directly for the mainstem Bay since December, 1987. Since January, 1988 it has been a calculated parameter.

PARAMETER NAME: TSS, total suspended solids, gravimetric, dried at 103-105°C

CBP METHOD: L01

EPA METHOD OR OTHER DESCRIPTION: 160.2

REFERENCE: EPA, 1983. USEPA-600/4-79-020. Method 160.2.

APHA. 1989. Method: 2540 D. Total Suspended Solids Dried at 103-105°C. Standard Methods for the Examination of Water and Wastewater. American Public Health Association, American Water Works Association, and Water Pollution Control Federation. Washington, D.C. 17th Edition. 1989

TSS data was not submitted for BAY 463 collected July 24-26, 2007.

PARAMETER NAME: WTEMP, water temperature, in-situ

CBP METHOD: F01

EPA METHOD OR OTHER DESCRIPTION: 170.1

REFERENCE: EPA, 1983. USEPA-600/4-79-020. Method 170.1

Process_Date: Unknown

Spatial_Data_Organization_Information: top

Direct_Spatial_Reference_Method: Point

Spatial_Reference_Information: top

Horizontal_Coordinate_System_Definition:

Geographic:

Latitude_Resolution: 0.0010

Longitude_Resolution: 0.0010

Geographic_Coordinate_Units: decimal minutes

Geodetic_Model:

Horizontal_Datum_Name: North American Datum of 1983

Ellipsoid_Name: Geodetic Reference System 80

Semi-major_Axis: 6,378,137

Denominator_of_Flattening_Ratio: 298.257

Entity_and_Attribute_Information: top

Overview_Description:

Entity_and_Attribute_Overview:

In the database there are 6 data tables submitted: WQ_DATA, WQ_DATA_BMDL, WQ_KD, WQ_CHLOROPHYLL, WQ_CRUISES, WQ-QAQC and WQ_EVENT.

Entity_and_Attribute_Detail_Citation:

WQ_CRUISES table contains the cruise name, dates and comments about the cruise. The WQ_EVENT table contains weather data for the stations. The WQ_KD table contains light data collected during the vertical profile on stations. WQ_CHLOROPHYLL table contains the absorbance values, sample volumes filtered and extraction volumes for chlorophyll samples. The WQ_DATA table contains physiochemical profile data and nutrient data. The WQ_DATA_BMDL table contains the actual instrument values obtained for samples below the method detection limit. The WQ_QAQC table contains the accuracy and precision data for the analyses.

U.S. Chesapeake Bay Program, Water Quality Database Design and Data Dictionary, www.chesapeakebay.net/data/index.htm. See database Lookup Tables.

Distribution_Information: top

Distributor:

Contact_Information:

Contact_Organization_Primary:

Contact_Organization: Old Dominion University, Department of Chemistry and Biochemistry

Contact_Person: Suzanne C. Doughten

Contact_Position: Water Quality Supervisor

Contact_Address:

Address_Type: mailing and physical

Address: 4211 Colley Ave.

City: Norfolk

State_or_Province: Virginia

Postal_Code: 23508

Country: USA

Contact_Voice_Telephone: 757-451-3043

Contact_Facsimile_Telephone: 757-440-4005

Contact_Electronic_Mail_Address:

sdoughte_no_spam_@odu.edu [remove _no_spam_ for valid email address]

Distribution_Liability: none provided

Standard_Order_Process:

Digital_Form:

Digital_Transfer_Information:

Format_Name: Access Database File

Format_Version_Number: 97

Transfer_Size: 0.012 MB

Digital_Transfer_Option:

Online_Option:

Computer_Contact_Information:

Network_Address:

Network_Resource_Name: <http://www.chesapeakebay.net>

Fees: 0

Metadata_Reference_Information: top

Metadata_Date: 20021029

Metadata_Review_Date: 20080505

Metadata_Contact:

Contact_Information:

Contact_Organization_Primary:

Contact_Organization: Old Dominion University, Department of Chemistry and Biochemistry

Contact_Person: Suzanne C. Doughten

Contact_Position: Water Quality Supervisor

Contact_Address:

Address_Type: mailing and physical

Address: 4211 Colley Ave.

City: Norfolk

State_or_Province: Virginia

Postal_Code: 23508

Country: USA

Contact_Voice_Telephone: 757-451-3043

Contact_Facsimile_Telephone: 757-440-4005

Contact_Electronic_Mail_Address:

sdoughte_no_spam_@odu.edu [remove _no_spam_ for valid email address]

Metadata_Standard_Name: FGDC-STD-001-1998

Metadata_Standard_Version: FGDC-STD-001-1998

Generated by mp version 2.8.22 on Tue May 06 12:22:00 2008