Metadata: Identification_Information: Citation: Citation_Information: Originator: Virginia Department Of Environmental Quality Publication_Date: 20240825 Title: Virginia Chesapeake Bay Tributary Water Quality Monitoring Program Data Geospatial_Data_Presentation_Form: Spatial data set Online_Linkage: [https://www.chesapeakebay.net/what/data] Description: Abstract: Water quality monitoring results from July 1, 2024 through June 30, 2025 consisting of routine (monthly) monitoring of 43 stations located in the Elizabeth, James, York and Rappahannock tributaries of the Chesapeake Bay. General water quality parameters monitored include dissolved oxygen, pH, temperature, salinity, specific conductance and light penetration via secchi depth and, at select sites, Licor readings. Nutrient loadings and their effect on water quality are also monitored through particulate carbon, particulate nitrogen, particulate phosphorus, dissolved nitrate, dissolved nitrate plus nitrite, dissolved orthophosphorus, total suspended solids, total nonvolatile solids, total dissolved nitrogen and total dissolved phosphorus and dissolved ammonia. Purpose: This monitoring data program was established to determine the status and trends of nutrient and sediment concentrations in the James, York and Rappahannock tributaries of Virginia and to collect data used to develop, calibrate and verify water quality models for Virginia's tributaries. Time_Period_of_Content: Time_Period_Information: Range_of_Dates/Times: Beginning_Date: 20240701 Ending_Date: 20250630 Currentness_Reference: Ground Condition Status: Progress: Complete Maintenance_and_Update_Frequency: As needed Spatial_Extent: Bounding_Coordinates: West_Bounding_Coordinate: -80.53758 East_Bounding_Coordinate: -074.5759 North_Bounding_Coordinate: +42.979 South_Bounding_Coordinate: +36.66154 Keywords: Theme: Theme_Keyword_Thesaurus: CIMS Subject Keyword List Theme_Keyword: Monitoring Theme_Keyword: Nutrients Theme_Keyword: Chlorophyll Theme_Keyword: Water Quality Theme_Keyword: Dissolved oxygen Theme_Keyword: Nitrogen Theme_Keyword: Particulates Theme_Keyword: pH Theme_Keyword: Phosphorus Theme_Keyword: Salinity Theme_Keyword: Specific conductance Theme_Keyword: Water temperature Theme_Keyword: Sediment Place: Place_Keyword_Thesaurus: User Defined Keyword List Place_Keyword: Appomattox River Place_Keyword: Chesapeake Place_Keyword: Chesapeake Bay Place_Keyword: Chickahominy River Place_Keyword: Corrotoman River Place_Keyword: Cumberland Place_Keyword: Elizabeth River Place_Keyword: Frederick Place_Keyword: Fredericksburg Place_Keyword: Hopewell Place_Keyword: James River Place_Keyword: Lancaster Place_Keyword: Mattaponi River Place_Keyword: Newport News Place_Keyword: Norfolk Place_Keyword: Pamunkey River Place_Keyword: Po River Place_Keyword: Rappahannock River Place_Keyword: Virginia Place_Keyword: York River Terms_of_Use: None Data_Resource_Type: Downloadable Dataset URL: https://www.chesapeakebay.net/what/data URL: https://www.epa.gov/waterdata/water-quality-data Metadata_Reference_Information: Chesapeake Bay Program Metadata Specification, May 7, 2025 [https://www.chesapeakebay.net/what/publications/chesapeake-bay-program-metadata-specification] Metadata_Date: 20250825 Metadata_Review_Date: 20250825 Metadata_Contact: Contact_Information: Contact_Organization_Primary: Contact_Organization: Virginia Department Of Environmental Quality Contact_Person: Cindy S. Johnson Contact_Position: Grant Coordinator Contact_Address: Address_Type: Mailing Address: PO BOX 1105 City: Richmond State_or_Province: VA Postal_Code: 23218 Country: USA Contact_Voice_Telephone: 804-698-4000 Contact_Facsimile_Telephone: Contact_Electronic_Mail_Address: cindy.johnson_no_spam_@deq.virginia.gov [remove _no_spam_ for valid email address] Data_Set_Credit: Virginia Department of Environmental Quality (VADEQ) staff collected the samples and processed the data. The Division of Consolidated Laboratory Services analyzed the chemical parameters. Access_Constraints: None Data_Quality_Information: Refer to Problem codes associated within the dataset and DAITS issues located at [https://www.chesapeakebay.net/what/publications/data-analysis-issues-tracking-system-daits] Process_Steps: Process_Description: Data collected for this project are obtained using the methods from the following resources: Methods and Quality Assurance for Chesapeake Bay Water Quality Monitoring Programs. Chesapeake Bay Program, May 2017, CBP/TRS-319-17 [https://d38c6ppuviqmfp.cloudfront.net/documents/CBPMethodsManualMay2017.pdf]. VA Dept. Of Environmental Quality - Quality Assurance Quality Control Project Plan for the Virginia Tributary Monitoring Program effective date Jul 1 2024 [https://www.deq.virginia.gov/our-programs/water/water-quality/monitoring/chesapeake-bay-monitoring]. PARAMETER NAME: DO METHOD SUMMARY:A profile of dissolved oxygen is obtained from the water column from 1 meter above the bottom to 1 meter below the surface in 1 meter increments utilizing an Optical Probe calibrated in water saturated air attached to a YSI Exo1 Sonde. Multiprobe readings are allowed to equilibrate prior to recording a value. UNITS OF MEASUREMENT: mg/l METHOD: F04 PROCESS DATE: April 2017- present PARAMETER: EPAR_S METHOD SUMMARY: Par light attenuation profiles are recorded utilizing a LICOR meter. The EPAR_S is obtained from the deck sensor while the EPARU_Z is obtained from the water column. EPAR_S readings are obtained from the deck sensor prior to obtaining the water column values. PARAMETER: EPARU_Z METHOD SUMMARY: Par light attenuation profiles are recorded utilizing a LICOR meter. The EPARU_S is obtained from the deck sensor while the EPARU_Z is obtained from the water column. Readings are obtained from the deck sensor prior to obtaining the water column values. The water probe is lowered into the water column and initial readings are obtained from just below the surface and 0.5 m. The profile continues in 0.5 m increments until the bottom is reached or a value of approximately 10 um/m**2/s is obtained. Additionally LiCor readings were obtained from all Bay Program tributary sites however, in April 2007 LiCor LiCor readings became restricted to phytoplankton stations phytoplankton sampling occurs (RET5.2, TF5.5, RET3.1, TF3.3, RET4.3, TF4.2 and SBE5). EXCEPTIONS: While the initial readings are obtained just below the surface, the depth is recorded as 0.1 meters in the database. UNITS OF MEASUREMENT: UM/M**2/S METHOD: F01 PROCESS DATE: January 1994 - present PARAMETER NAME: PH METHOD SUMMARY: A calibrated pH electrode (correcting for temperature) attached to a multi-probe sonde, is lowered into the water column and readings are obtained from one meter above the bottom to 1 meter below the surface in 1 meter increments. The electrode readings are allowed to stabilize prior to taking the meter readings. Since 2017 DEQ has used YSI EXO1 or EXO1s (or comparable YSI units). Prior to April 2002 pH was only obtained a depth 1 meter above the bottom and 1 meter below the surface. From 1985-July 2007, profiles were obtained in 2 meter increments. From 1986-2017 pH profiles were obtained utilizing Sonde units and prior to 2007 pH was collected at odd depths only. EXCEPTIONS: None UNITS OF MEASUREMENT: Standard METHOD: F01 PROCESS DATE: July 1984 - present PARAMETER NAME: SALINITY METHOD SUMMARY:A profile of salinity is obtained from the water column from 1 meter above the bottom to 1 meter below the surface in 1 meter increments utilizing a YSI Exo1. Multiprobe readings are allowed to equilibrate prior to recording a value. CHANGES IN COLLECTION PROCESS: From 1985-July 2007, profiles were obtained in 2 meter increments. After 2017 Sonde sondes were phased out for YSI Exo1 sondes (or comparable YSI units). EXCEPTIONS: None UNITS OF MEASUREMENT: ppt METHOD: F01 PROCESS DATE: July 1984 - present PARAMETER NAME: SECCHI METHOD SUMMARY: Lines calibrated in 0.1 m are tied to 20 in diameter Secchi disks. The disk is lowered into the water in a shaded location and the depth at which the disk disappears then raised until it reappears. The average of the depths at which the disk appears and reappears is calculated and used as Secchi depth. CHANGES IN COLLECTION PROCESS: Some regions initially utilized a 30 cm diameter Secchi disk and then changed to a 20 cm disk early in the program. EXCEPTIONS: Because of the shallow depth at station TF5.2 secchi depth is not collected. UNITS OF MEASUREMENT: meters METHOD: F01 PROCESS DATE: July 1984 - present PARAMETER NAME: SPCOND METHOD SUMMARY: A profile of specific conductance is obtained from the water column from 1 meter above the bottom to 1 meter below the surface in 1 meter increments utilizing a calibrated conductivity sensor attached to a multi-probe. Multiprobe readings are allowed to equilibrate prior to recording a value. CHANGES IN COLLECTION PROCESS: From 1985-July 2007, profiles were obtained in 2 meter increments. Since 2017 YSI EXO1 sondes (or comparable YSI units). EXCEPTIONS: None UNITS OF MEASUREMENT: umhos/cm METHOD: F01 PROCESS DATE: July 1984 - present PARAMETER NAME: WTEMP METHOD SUMMARY: A profile of water temperature is obtained from the water column from 1 meter above the bottom to 1 meter below the surface in 1 meter increments utilizing a temperature probe (thermistor) attached to a multi-probe sonde. Probe readings are allowed to equilibrate prior to recording a value CHANGES IN COLLECTION PROCESS: From 1985-July 2007, profiles were obtained in 2 meter increments. Since 2017 YSI EXO1 sondes have been used for profiles. EXCEPTIONS: UNITS OF MEASUREMENT: Degrees Celsius METHOD: F01 PROCESS DATE: July 1984 - present PARAMETER NAME: CHLA METHOD SUMMARY: Sample water is collected in a 2 liter brown plastic bottle from 1 meter below the surface utilizing a pump and hose. The sample is thoroughly mixed and between 300 ml - 1000 ml are filtered on 1-3 GF/F filters. Samples are filtered through a 47 mm diameter (0.7 um pore size) Whatman GF/F filter which are then folded in half to protect the contents, placed in a petri dish, sealed in aluminum, marked with station ID, date, time and depth of collection and then placed in a Ziplock bag and iced to 4 degrees Celsius for pickup by courier. Analysis consists of a monochromatic, spectrophotometric determination, correcting for pheophytin and turbidity. Optical density data reported by DCLS between Sept 1998 and February 2001 were only reported to 3 decimal places. Chlorophyll a values were calculated utilizing optical densities to the 4th place. UNITS OF MEASUREMENT: ug/l METHOD: L01 PROCESS DATE: June 1985 -present PARAMETER: DOC METHOD SUMMARY: Filtered samples (0.7 um filter) are preserved with sulfuric acid to a pH<2 and delivered by courier to VADCLS. Once received, the filters are purged with nitrogen 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. UNITS OF MEASUREMENT: mg/l METHOD: L01 PROCESS DATE: January 1994 - December 1994 and July 2003 - October 2009. PARAMETER: FCOLI METHOD SUMMARY: A 125 ml sample is collected from the surface and labeled for date, time, depth, collector and station. Once the label is applied, the sample is immediately placed on ice to preserve it for courier delivery to VADCLS. In the laboratory, several different volumes of sample are filtered through sterile membrane filters, which are placed in M-FC medium and incubated at 44.5 +/- 0.2 degrees Celsius for 24 +/-2 hours. Fecal colonies are identified by their blue color. UNITS OF MEASUREMENT: colonies/100 mls METHOD: L02 PROCESS DATE: - present PARAMETER NAME: FSS METHOD SUMMARY: Sample water is collected into cubitainers from 1 meter above the bottom and 1 meter below the surface via a pump and hose apparatus and labeled for date, time, depth, collector and station. Once the label is applied, the sample is immediately placed on ice to preserve it for courier delivery to the VADCLS. In the laboratory, the sample is filtered through a pre-weighed filter and dried to a constant weight at 103-105 degrees Celsius (TSS). The total suspended solids (TSS) are then combusted at 550 +/- degrees centigrade for 20 minutes in a muffle furnace and weighed. The final weight of the residue in mg/l is the fixed suspended solids (FSS). UNITS OF MEASUREMENT: mg/l METHOD: L01 PROCESS DATE: August 1984 - present PARAMETER NAME: HARDNESS METHOD SUMMARY: Sample water is collected in a gallon cubitainer from 1 meter below the surface via a pump and hose container and labeled for date, time, depth, collector and station. Once the label is applied, the sample is immediately placed on ice to preserve it for courier delivery to the VADCLS. In the laboratory, MgEDTA is added to the sample, which exchanges magnesium on an equivalent basis for any calcium and/or other cations to form a more stable EDTA chelate. The free magnesium reacts with calmagite at a pH of 10 to give a red-violet complex, which is measured colorimetrically at 520 nm. UNITS OF MEASUREMENT: mg/l METHOD: L02 PROCESS DATE: April 1992 - present PARAMETER NAME:NH4F METHOD SUMMARY: Sample water is collected from 1 meter below the surface and 1 meter above the bottom in 1/2 gallon plastic containers via a pump and hose apparatus. The sample is mixed thoroughly and immediately filtered through a 47 mm diameter (0.7 um pore size) Whatman glass fiber filter. The filtrate is collected into a 250 ml bottle, labeled with station, date, time, depth and collector and place on ice for transportation to VADCLS. In the laboratory, sample is exposed to alkaline phenol and hypochlorite and forms indophenol blue. The absorbency of which is proportional to ammonia concentrations. The solution's color is intensified by sodium nitroprusside, heated and read colorimetrically using a Seal Analyzer. CHANGES IN COLLECTION PROCESS: A Seal Analyzer has been used for this analysis since July 6, 2023. UNITS OF MEASUREMENT: mg/l METHOD: L01 PROCESS DATE: June 1984 - present PARAMETER NAME: NO2F METHOD SUMMARY: Sample water is collected in a 1/2 gallon plastic container and immediately filtered through a 47 mm diameter (0.7 um pore size) Whatman glass fiber filter. The filtrate is collected into a 250 ml bottle, labeled with station, date, time, depth and collector and place on ice for transportation to VADCLS (See the Quality Assurance/Quality Control Project Plan for the Virginia Monitoring Program for further information). In the laboratory, the filtered sample is passed through a granulated copper-cadmium column and nitrite is determined by diozotizing with sulfanilamide and coupling with N-(1-napthyl)ethylenediamine dihydrochloride to form a highly colored azo dye which is measured colorimetrically. CHANGES IN COLLECTION PROCESS: A Seal Analyzer has been used for this analysis since July 6, 2023. UNITS OF MEASUREMENT: mg/l METHOD: L01 PROCESS DATE: July 1984 - present PARAMETER NAME: NO23F METHOD SUMMARY: Sample water is collected in a 1/2 gallon plastic container and immediately filtered through a 47 mm diameter (0.7 um pore size) Whatman glass fiber filter. The filtrate is collected into a 250 ml bottle, labeled with station, date, time, depth and collector and place on ice for transportation to VADCLS. In the laboratory, the filtered sample is passed through a granulated copper-cadmium column to reduce nitrate to nitrite. The nitrite (originally present plus reduced nitrate) is determined by diozotizing with sulfanilamide and coupling with N-(1-napthyl)ethylenediamine dihydrochloride to form a highly colored azo dye which is measured colorimetrically. Nitrate and nitrite are determined separately by conducting the analysis with and without the reduction step. Nitrate maybe obtained by subtracting the concentration of nitrite from the concentration of nitrite plus nitrate (Refer to the Chesapeake Bay Program methods paper (March 3, 1999) for further information). CHANGES IN COLLECTION/REPORTING PROCESS: A Seal analyzer was used for this p July 6, 2023 DCLS switched to a Seal Analyzer for this analysis. Also, while this parameter was analyzed by VADCLS on behalf of DEQ. DEQ reported the calculated parameter of NO3F instead of NO23F until July 1986 for all stations and from May 97 - Dec 97 for stations TF3.1B, TF3.2, and TF3.1E. DAITS ISSUES: 032 UNITS OF MEASUREMENT: mg/l METHOD: L01 (C01 1984-1986 and May 97 - Dec 97 for stations TF3.1B, TF3.2, and TF3.1E). PROCESS DATE: July 1986 - present PARAMETER NAME: NO3F METHOD SUMMARY: Sample water is collected in a 1/2 gallon plastic container and immediately filtered through a 47 mm diameter (0.7 um pore size) Whatman glass fiber filter. The filtrate is collected into a 250 ml bottle, labeled with station, date, time, depth and collector and place on ice for transportation to VADCLS. In the laboratory, the filtered sample is passed through a granulated copper-cadmium column to reduce nitrate to nitrite. The nitrite (originally present plus reduced nitrate) is determined by diozotizing with sulfanilamide and coupling with N-(1-napthyl)ethylenediamine dihydrochloride to form a highly colored azo dye which is measured colorimetrically. Nitrate and nitrite are determined separately by conducting the analysis with and without the reduction step. Nitrate maybe obtained by subtracting the concentration of nitrite from the concentration of nitrite plus nitrate. CHANGES IN COLLECTION/REPORTING PROCESS: Initial filtration utilized 50 mm filters. Prior to January 1994 VADCLS used a Technicon Auto Analyzer II, from January 1994- July 2023 a Skalar analyzer was used and on July 6, 2023 DCLS switched to a Seal Analyzer for this analysis. DEQ reported this calculated parameter instead of NO23F until July 1986. This parameter continues to be reported to DEQ but is no longer reported to the Chesapeake Bay C4 database. UNITS OF MEASUREMENT: mg/l METHOD: C01 PROCESS DATE: July 1986 - December 1997 PARAMETER NAME: PC METHOD SUMMARY: Sample water is collected in a 1/2 gallon plastic container from 1 meter above the bottom and 1 meter below the surface. The sample is thoroughly mixed and filtered through a 25 mm Gelman glass fiber filter (0.7 um pore size). Filtering takes place immediately whenever possible but no later than 2 hours after collection. The filter is placed in a Petri dish labeled with station id, date, time, depth and collector. The petri dish is placed inside a Ziplock bag and stored on ice for transport to VADCLS. At the laboratory the filter is combusted at 975 - 1050 degrees Celsius using an elemental analyzer. Organic and inorganic carbons form carbon dioxide gas, which passes through a series of thermal conductivity detectors. CHANGES IN COLLECTION/REPORTING PROCESS: Initially PC was collected on a 13 mm filter. DEQ changed to 25 mm in March 1985. UNITS OF MEASUREMENT: mg/l METHOD: L01 PROCESS DATE: January 1994 - present PARAMETER NAME: PHEO METHOD SUMMARY: Sample water is collected in a 2 liter brown plastic bottle from 1 meter below the surface utilizing a pump and hose. The sample is thoroughly mixed and between 300 ml - 1000 ml are filtered through 1-3 47 mm diameter (0.7 um pore size) GF/F filters, placed in a petri dish covered in foil and marked with station ID, date, time and depth of collection. The foil covered petri dish is placed in a Ziplock bag and placed on ice for delivery to the lab (See the Quality Assurance/Quality Control Project Plan for the Virginia Monitoring Program for further information). Analysis consists of a monochromatic, spectrophotometric determination, correcting for pheophytin and turbidity. The filters are placed in 90% aqueous acetone and ground to a uniform consistency with a tissue grinder. Samples are steeped overnight at 4 degrees Celsius in the dark. The extract is clarified by centrifugation. Spectrophotometric optical density readings are taken before and after acidification using 2 drops of 1 N HCL. Pheophytin is calculated from optical density readings using Lorenzen's equation. CHANGES IN COLLECTION PROCESS: Initially chlorophyll and pheophytin determinations were made by VCU. In September of 1998 VADCLS began to perform the analyses. Whole water samples were collected until May 1999 when VADEQ began field filtration. From Sept 1998 through February 2001 DCLS reported optical densities to 3 decimal places. Pheophytin values were determined with 4 decimal places. UNITS OF MEASUREMENT: mg/l METHOD: L01 PROCESS DATE: June 1985 - present PARAMETER NAME: PN METHOD SUMMARY: Sample water is collected in a 2 liter brown plastic bottle from 1 meter above the bottom and 1 meter below the surface. The sample is thoroughly mixed and filtered through a 25 mm Gelman glass fiber filter (0.7 um pore size). Filtering takes place immediately whenever possible but no later than 2 hours after collection. The filter is placed in a petri dish labeled with station id, date, time, depth and collector. The petri dish is placed inside a Ziplock bag and stored on ice for transport to VADCLS. At the laboratory the filter is combusted at 975 - 1050 degrees Celsius using an elemental analyzer. Organic and inorganic carbons form carbon dioxide gas which passes through a series of thermal conductivity detectors. CHANGES IN COLLECTION/REPORTING PROCESS: Initially PN was collected on a 13 mm filter. DEQ changed to 25 mm in March 1985. UNITS OF MEASUREMENT: mg/l METHOD: L01 PROCESS DATE: January 1994 - present PARAMETER NAME: P04F METHOD SUMMARY: Sample water is collected in a 2 liter brown plastic bottle from 1 meter above the bottom and 1 meter below the surface. The sample is thoroughly mixed and filtered through a 47 mm glass (0.7 um pore size) Whatman fiber filter. The filtrate is collected into a 250 ml bottle, labeled with station, date, time, depth and collector and place on ice for transportation to VADCLS. Ammonium molybdate and antimony potassium tartrate in an acid medium are added to sample to form an antimony-phospho-molybdate complex. This complex is reduced to an intensely blue-colored complex by ascorbic acid and is measured colorimetrically using a Seal. A salinity correction is applied as necessary (refer to Chesapeake Bay Program methods paper (March 3, 1999) for further information). CHANGES IN COLLECTION/REPORTING PROCESS: DCLS has utilized a Seal Analyzer since July 6, 2023. UNITS OF MEASUREMENT: mg/l METHOD: L01 PROCESS DATE: July 1984 - present PARAMETER NAME: PP METHOD SUMMARY: Sample water is collected in a 2 liter brown plastic bottle from 1 meter above the bottom and 1 meter below the surface. The sample is thoroughly mixed and filtered through a 47 mm Whatman glass (0.7 um pore size) fiber filter. Filtering takes place immediately whenever possible but no later than 2 hours after collection. The filter is placed in a petri dish labeled with station, date, time, depth and collector. The petri dish is then placed in a Ziploc bag and placed on ice for transportation to VADCLS. The particulates on the 0.7 um filter are weighed, then combusted at 550 degrees Celsius to convert organically bound phosphorus to phosphate. Phosphate is extracted with HCL and measured by the automated ascorbic acid method for PO4. CHANGES IN COLLECTION/REPORTING PROCESS: Initial filtration utilized 50 mm filters. In January 1994 VADCLS began using a Skalar analyzer for nutrient series instead of the Technicon Auto Analyzer II. UNITS OF MEASUREMENT: mg/l METHOD: L01 PROCESS DATE: July 1984 - present PARAMETER NAME: SIF METHOD SUMMARY: Sample water is collected in a 2 liter brown plastic bottle from 1 meter above the bottom and 1 meter below the surface. The sample is thoroughly mixed and filtered through a 47 mm Whatman glass (0.7 um pore size) fiber filter. The filtrate is collected into a 250 ml bottle, labeled with station, date, time, depth and collector and place on ice for transportation to VADCLS (See the Quality Assurance/Quality Control Project Plan for the Virginia Monitoring Program for further information). An automated colorimetric method based on the reduction of silicomolybdate in acidic solution to 'Molybdenum blue' (herteropoly blue) by ascorbic acid. Oxalic acid is introduced to the sample stream before addition of ascorbic acid to eliminate interference from phosphates. The absorbance is determined at 660 or 815 nm. CHANGES IN COLLECTION/REPORTING PROCESS: DCLS has utilized a Seal Analyzer since July 6, 2023. DAITS ISSUE: 032 UNITS OF MEASUREMENT: mg/l METHOD: L03 PROCESS DATE: July 1984-July 1991 January 1994-present PARAMETER NAME: TDN METHOD SUMMARY: Sample water is collected in a 2 liter brown plastic bottle from 1 meter above the bottom and 1 meter below the surface. The sample is thoroughly mixed and filtered through a 47 mm Whatman glass (0.7 um pore size) fiber filter. The filtrate is collected into a 250 ml bottle, labeled with station, date, time, depth and collector and place on ice for transportation to VADCLS. The filter sample is 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. CHANGES IN COLLECTION/REPORTING PROCESS: DCLS has utilized a Seal Analyzer since July 6, 2023. UNITS OF MEASUREMENT: mg/l METHOD: L01 PROCESS DATE: January 1994 - present PARAMETER NAME: TDP METHOD SUMMARY: Sample water is collected in a 2 liter brown plastic bottle from 1 meter above the bottom and 1 meter below the surface. The sample is thoroughly mixed and filtered through a 47 mm Whatman glass (0.7 um pore size) fiber filter. The filtrate is collected into a 250 ml bottle, labeled with station, date, time, depth and collector and place on ice for transportation to VADCLS. The filter sample is 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. CHANGES IN COLLECTION/REPORTING PROCESS: DCLS has utilized a Seal Analyzer since July 6, 2023. UNITS OF MEASUREMENT: mg/l METHOD: L01 PROCESS DATE: July 1984 - present PARAMETER NAME: TN METHOD SUMMARY: This parameter is calculated as PN + TDN = TN. PARAMETER NAME: TP METHOD SUMMARY: This parameter is calculated as PP + TDP = TP. PARAMETER NAME: TSS METHOD SUMMARY: Sample water is collected into a quart cubitainer (or larger container) from 1 meter above the bottom and 1 meter below the surface via a pump and hose apparatus and labeled for date, time, depth, collector and station. Once the label is applied, the sample is immediately placed on ice to preserve it for courier delivery to the lab. In the laboratory, the sample is filtered through a pre-weighed filter and dried to a constant weight at 103-105 degrees Celsius. The final weight of the residue in mg/l is the total suspended solids. UNITS OF MEASUREMENT: mg/l METHOD: L01 PROCESS DATE: August 1984 - present PARAMETER NAME: TURB_NTU METHOD SUMMARY: Sample water is collected in a gallon cubitainer from 1 meter below the surface via a pump and hose container and labeled for date, time, depth, collector and station. Once the label is applied, the sample is immediately placed on ice to preserve it for courier delivery to the lab. A comparison of the intensity of light scattered by the sample with the intensity of light scattered by a standard reference suspension of formazin. Readings, in NTUs are considered comparable to FTUs. UNITS OF MEASUREMENT: NTU METHOD: L01 PROCESS DATE: January 1993 - present. PARAMETER NAME: VSS METHOD SUMMARY: Sample water is collected into a quart cubitainer from 1 meter above the bottom and 1 meter below the surface via a pump and hose apparatus and labeled for date, time, depth, collector and station. Once the label is applied, the sample is immediately placed on ice to preserve it for courier delivery to the lab (See the Quality Assurance/Quality Control Project Plan for the Virginia Monitoring Program for further information). In the laboratory, the sample is filtered through a pre-weighed filter and dried to a constant weight at 103-105 degrees Celsius (TSS). The total suspended solids (TSS) are then combusted at 550 +/- degrees centigrade for 20 minutes in a muffle furnace. The final weight of the residue in mg/l is the fixed suspended solids (FSS). The difference between the total suspended solids and the fixed suspended solids represents the volatile suspended solids. This is a calculated parameter that continues to be collected by DEQ but is not reported to CIMS. UNITS OF MEASUREMENT: mg/l METHOD: C01 PROCESS DATE: August 1984 - July 1991 Process_Date: Unknown Attribute_Accuracy: Refer to Virginia DEQ Quality Assurance and Quality Control Project Plan Appendices for Log of Significant Changes and Chesapeake Bay Program's DAITS Attribute_Accuracy_Report: As a participating member of the Chesapeake Bay program, the Virginia Tributary Monitoring Program strives to provide high quality data. To assess the quality of a data set, the Chesapeake Bay Program utilizes detailed documentation of methods, protocols and quantitative proof of measurement control. Quality assurance data for chemical analyses measure precision and accuracy to determine both the repeatability of measurements and the closeness of an analytical measurement to a true value. The VADEQ quality assurance data include precision and accuracy comparisons both within the Virginia Division of Consolidated Laboratory Services (VADCLS, provides analytical services to VADEQ) and comparing results from VADCLS to other laboratories participating in the CB monitoring program. Field QA Data: Water temperature, specific conductance, dissolved oxygen and pH measurements are all obtained with electronic field instrumentation. The instruments are calibrated for all parameters as recommended by the manufacturer. All parameters are calibrated at the start of each sampling week and checked at the end of each sampling day for drift. Dissolved Oxygen and depth are calibrated daily while pH and specific conductance if end of day checks are outside of tolerance. The temperature of the instruments are calibrated against a certified thermometer annually and the instruments are also visually inspected any source of equipment problems prior to each sampling event. A log is kept of calibration results and maintenance requirements. A Secchi disk is used to determine water clarity. The Secchi disk lines are measured and marked using a meter stick. Water clarity is also determined through PAR measurements utilizing a LICOR meter. The meter is maintained according to manufacturer recommendations. Water samples are collected at most stations via a submersible pump and hose apparatus. The hoses are measured against a meter stick and marked in 1 meter increments with tape. The tape is replaced when necessary. VADEQ began collecting field duplicates (splits obtained via a "y" fitting on the hose) in February 1999 (although some regions did not begin collecting QA/QC samples until May of 1999). Field duplicates are designated with a SAMPLE_ID of FS1 or FS2. However, when variation between field replicates was observed, it was difficult to determine the source (i.e. field methods or laboratory methods). In an effort to further pinpoint the source of observed variation, VADEQ requested VADCLS to produce laboratory duplicates of the field duplicates whenever possible. These samples are designated in the CBP water quality database with a SAMPLE_ID of S1, S2, FS1, FS2 for field variation only or FS1/LS1, FS1/LS2, FS2/LS1and FS2/LS2 when laboratory variation is included in the analysis. VADEQ's Quality Assurance Project Plans (QAPPs) and Standard Operating Procedures (SOPs) and VADCLS laboratory methods for Chesapeake Bay Program Monitoring follow the guidelines set in "Methods and Quality Assurance for Chesapeake Bay Water Quality Monitoring Programs" (US Environmental Agency. CBP/TRS-19-17. May 2017). VADEQ's documents are reviewed by VADEQ and VADCLS in April of each year for method changes and correctness. Finalized QAPPs and SOPs and submitted annually to the Chesapeake Bay Program QA Coordinator for approval prior to the start of each monitoring year. VADEQ's QAPPs and SOPs are downloadable from https://www.deq.virginia.gov/our-programs/water/water-quality/monitoring/chesapeake-bay-monitoring. VADCLS QAPPs and SOPs are available from VADCLS upon request. Additional Comments: Due to the loss of 2 field personnel and weather, Stations RET5.2, LE5.1, LE5.2, LE5.3, LE5.4, EBE1, EBB01, SBE2, SBE5, RET4.1, RET4.3, LE4.1, LE4.2, LE4.3 were not collected in January. The James River samples were also lost in February and March (RET5.2, LE5.1, LE5.2, LE5.3, LE5.4), the York River stations were also lost in March (RET4.1, RET4.3, LE4.1, LE4.2, LE4.3) and the first day of the Elizabeth River were not collected in April (Eli2, LE5.6, LFA01, LFB01, ELD01, WBE1, WBB05 and ELE01). Laboratory QA: Water Quality analyses are performed by the Virginia Division of Consolidated Laboratories. Samples are rejected if improperly preserved to 6 Celsius degrees (plus or minus 2 degrees) or if they are not properly sealed or labeled. Field precision is estimated with field splits. The Division of Consolidated Laboratory Services in Virginia (VADCLS) performs chemical analyses for VADEQ Services in Virginia. VADCLS utilizes laboratory replicates and laboratory spike samples to estimate laboratory precision and accuracy. Ten percent of samples analyzed (on a parameter by parameter basis) by VADCLS are randomly selected for lab replicate analysis. These QA/QC measures are maintained by VADCLS and are not submitted to the CBP water quality database. To further assure the highest quality data, VADCLS determines minimum detection limits (MDLs) for each parameter and does not submit information below the calculated MDL. The MDL is the lowest concentration of an analyte that can be quantified with reliability. Participants in the CBP currently determine the MDL from three times the standard deviation of seven replicates of a low-level ambient water sample. When instrument values are below the MDL, the value of the parameter is set to the detection limit and QUALIFIER is set to < in the C4 database however below detection data is provided to the Bay Program so that it may be requested by scientists to be used in models and trends as needed. Inter-organization QA data: VADEQ requires that any laboratory analyzing data on their behalf for the CBP participate in the CBP Data Integrity Workgroup (DIWG, formerly the Analytical Methods and Quality Assurance Workgroup (AMQAW)) and through DIWG in the Coordinated split Sample Program (CSSP). The CSSP collects samples from the mainstem and tributary areas of the Chesapeake Bay. Participating laboratories then analyze the samples in triplicate and submit the results to DIWG. DIWG statistically compares the laboratory results to those of 3- 5 other participating laboratories. DIWG then identifies parameters having low inter-laboratory agreement, estimates the system variability, and then tries to improve the level of agreement (Refer to [https://d18lev1ok5leia.cloudfront.net/chesapeakebay/documents/chesapeake_bay_program_mainstem_coordinated_split_sample_program_report_1994-1998.pdf]. Additionally the Commonwealth of Virginia requires any laboratory analyzing data for regulatory purposes be certified to perform that analysis through the Virginia Environmental Laboratory Accreditation Process (VELAP certified). Since VADCLS is the VELAP authority for the Commonwealth, VADCLS is certified through the National Environmental Laboratory Accreditation Program conducted by the NELAC Institute or a comparable program. Data Analysis Issues Tracking System (DAITS): In 1990 the DAITS system was established to document program design changes and questions affecting the comparability of data submitted by various Chesapeake Bay participants. The DAITS system ensures the issues are thoroughly investigated and documented for future data users. Pending issues are usually referred to members of the appropriate Monitoring Subcommittee (MSC) workgroup for resolution and are stored at the Chesapeake Bay Program (Refer to the "Guide to Using the Chesapeake Bay Program Water Quality Monitoring Data" at www.chesapeakebay.net/wquality.html for further information). Logical_Consistency_Report: not applicable Completeness_Report: Parameters are omitted due to malfunction of equipment or when other considerations (e.g. poor weather or crew safety issues) preclude capturing the information. Entity_and_Attribute_Information: Overview_Description: Entity_and_Attribute_Overview: Virginia Tributary Water Quality Monitoring Program Water Quality Monitoring data from the Elizabeth, James, Rappahannock and York River Basins in Virginia Metadata_Standard_Name: FGDC-STD-001-1998 Metadata_Standard_Version: FGDC-STD-001-1998 Positional_Accuracy: Horizontal_Positional_Accuracy: Horizontal_Positional_Accuracy_Report: na Vertical_Positional_Accuracy: Vertical_Positional_Accuracy_Report: na Spatial_Data_Organization_Information: Direct_Spatial_Reference_Method: Point Spatial_Reference_Information: Horizontal_Coordinate_System_Definition: Geographic: Latitude_Resolution: 1.0E-5 Longitude_Resolution: 1.0E-5 Geographic_Coordinate_Units: Decimal degrees Geodetic_Model: Horizontal_Datum_Name: North American Datum of 1983 Ellipsoid_Name: Clarke 1866 Semi-major_Axis: 6,378,206.4 Denominator_of_Flattening_Ratio: 294.98 Distribution_Information: Distributor: Contact_Information: Contact_Organization_Primary: Contact_Organization: Chesapeake Bay Program Contact_Person: Mike Mallonee Contact_Position: Water Quality Data Manager Contact_Address: Address_Type: Mailing and Physical Address: 1750 Forest Drive, Suite 130 City: Annapolis State_or_Province: MD Postal_Code: 21401 Country: USA Contact_Voice_Telephone: 410.267.5785 Contact_Facsimile_Telephone: Contact_Electronic_Mail_Address: mmallonee_no_spam@chesapeakebay.net [remove _no_spam_ for valid email address] Distribution_Liability: None of the Chesapeake Bay Program partners nor any of their employees, contractors, or subcontractors make any warranty, expressed or implied, nor assume any legal liability or responsibility for the accuracy, completeness, or usefulness of any information or data contained within the web site. Reference to any specific commercial products, processes, or services or the use of any trade, firm, or corporation name is for the information and convenience of the public and does not constitute endorsement, recommendation or favoring by the Chesapeake Bay Program partners. Standard_Order_Process: Digital_Form: Digital_Transfer_Information: Format_Name: Ascii file, formatted for text attributes, declared formats Format_Information_Content: Light_Attenuation_Data, Monitoring_Event_Data, Optical_Density, Station_Information, and Water_Quality_Data. Digital_Transfer_Option: Online_Option: Computer_Contact_Information: Network_Address: Network_Resource_Name: [https://www.chesapeakebay.net/what/data] Access _Instructions: User defined data are available through the Chesapeake Bay Data Hub by choosing options from a picklist of all available data, date ranges, locations and parameters. Fees: none