PROGRAMS AND PLANS--National Hydrologic Benchmark Network: Fiscal Year 1996--October 1, 1995 to September 30, 1996
In Reply Refer To December 4, 1995
Mail Stop 412
OFFICE OF WATER QUALITY TECHNICAL MEMORANDUM NO. 96.02
Subject: PROGRAMS AND PLANS--National Hydrologic Benchmark Network:
Fiscal Year 1996--October 1, 1995 to September 30, 1996
This memorandum contains an outline of Program status and protocol for
operation of the Hydrologic Benchmark Network (HBN) for fiscal year (FY)
1996. All personnel responsible for collecting HBN samples should read
and have their own copy of this memorandum. Network data collection can
be significantly enhanced when personnel responsible for field data
collection are informed of changes in sample collection and processing
procedures.
NETWORK OPERATIONS, FY 1996
HYDROLOGIC BENCHMARK NETWORK
Sampling frequency for all stations in the Benchmark Network will be
QUARTERLY in FY 1996; this is subject to change depending on funding
availability. The three stations that were discharge only
(02178400--Tallulah River near Clayton, GA; 05014500--Swiftcurrent Creek
at Many Glacier, MT; 06478540--Little Vermilion River near Salem, SD) are
discontinued as part of the Benchmark Program as of October 1, 1995.
Active stations are listed in Appendix A. Districts are encouraged to use
the sample collection and processing protocol for filtered samples (OWQ
Technical Memorandum 94.09) if they are equipped and ready to do so.
Decreasing budgets and increasing costs continue to be a problem.
Therefore, the Benchmark Program will be evaluated during FY 1996 and
changes in the number of stations and the way they are operated are
likely in FY 1997.
NOTES for FY 1996:
1. Field Alkalinity
The results of the National Field Quality Assurance proficiency tests
show that field personnel continue to have problems determining
alkalinity in the field, especially with the Hach titrator. The Hach
titrator method for determination of alkalinity is documented in Appendix
C. All individuals collecting Network samples should be familiar with the
method.
2. Sediment Samples
Suspended-sediment concentration and sand-fine split are required for all
NASQAN and Benchmark samples. Samples for sediment analysis are to be
collected in a separate set of bottles (to be composited at the sediment
lab), and are NOT to be taken from the churn splitter. If NAWQA samples
are being collected at the same time as HBN samples, and a cone splitter
is being used, the sediment sample can collected from the cone splitter.
See Open-File Report 86-531 (Field Methods for Measurement of Fluvial
Sediment by Edwards and Glysson) for details on collection of sediment
samples.
3. Samplers
Tests of existing samplers to determine their acceptability for
collection of trace-element samples have shown that all samplers, except
the D-77 and frame samplers (with a teflon or polypropylene bottle and/or
a teflon or Reynolds oven bag) and the DH-81 (with a teflon or
polypropylene bottle), contaminate samples at levels that are significant
at the microgram per liter (parts per billion) level. OWQ realizes that
these samplers cannot accommodate all environmental conditions; the
Instrumentation Committee (ICOM) has recommended development of
additional, non-contaminating samplers and the Federal Interagency
Sedimentation Project (FISP) is in the process of developing a 1-L
non-contaminating sampler.
All samplers being used for the collection of trace-element samples
(including weighted-bottle samplers) are to be coated. The FISP now uses
a Plasti-Dip coating on all new samplers. Older samplers can be recoated,
if necessary. Contact Wayne O'Neal at FISP for more information. His
phone number is 601-634-3735.
4. Barometric Pressure
Barometric pressure is to be measured with a pocket altimeter-barometer
and the value recorded on the field sheet and stored in the data base
(parameter code 00025). Barometric pressure can be read and reported to
the nearest 1 mm Hg, unless the barometer that is used is not
sufficiently accurate. The barometers that are currently available from
HIF are accurate to +/- 0.5 mm Hg. Make sure that the barometer is
properly calibrated using the UNCORRECTED or STATION pressure that is
obtained from the nearest National Weather Service office. Note that the
pressure reported on radio and television is corrected to sea level.
5. Recording Field Measurement Information
The times that individual field measurements are made, the location of
the measurements (from churn, side of stream, center of flow, point
sample, depth-integrated sample), and the method used should be recorded
on the field sheets. Because field measurements are often made some time
before or after the chemical-quality sample is collected, it is important
to note the time(s) (even though it cannot be stored in the NWIS I data
base). Dissolved oxygen should be measured at the center of flow whenever
possible. Use of the National Field Forms is recommended. They are
available from the QW Service Unit in Ocala (edoc to OCALAMAN).
6. Bacteria
Every effort should be made to obtain bacteria counts in the ideal range.
Keeping records of flow, volumes filtered, and counts in the field
folder, and referring to them each time bacteria samples are processed
should help in obtaining ideal counts most of the time. If counts are
consistently low, and sediment does not interfere, volumes greater than
100 mL can be filtered. See TWRI Book 5, Chapter A4 for correct methods
for calculating bacteria counts.
7. Storing Sampler Type in Data Base
In light of the concerns about potential contamination from samplers, it
is very important that the type of sampler used be known. This
information can be provided by storing SAMPLER TYPE under parameter code
84164. Currently-available values for this code are given below. Because
of the limitations of NWIS I, only the type of sampler used for
collecting chemical samples needs to be stored. Note-- these are the
correct codes; the codes on the National Field Form are incorrect.
84164 100.00VAN DORN SAMPLER
84164 110.00SEWAGE SAMPLE
84164 120.00VELOCITY INTEGRATED SAMPLE
84164 125.00KEMMERER BOTTLE
84164 3001.00Sampler, US DH-48
84164 3002.00Sampler, US DH-59
84164 3003.00Sampler, US DH-75P
84164 3004.00Sampler, US DH-75Q
84164 3005.00Sampler, US DH-76
84164 3006.00Sampler, US D-43
84164 3007.00Sampler, US D-49
84164 3008.00Sampler, US D-49AL
84164 3009.00Sampler, US D-74
84164 3010.00Sampler, US D-74AL
84164 3011.00Sampler, US D-77
84164 3012.00Sampler, US P-46
84164 3013.00Sampler, US P-50
84164 3014.00Sampler, US P-61-A1
84164 3015.00Sampler, US P-63
84164 3016.00Sampler, US P-72
84164 3017.00Sampler, US U-59
84164 3018.00Sampler, US U-73
84164 3019.00Sampler, US PS-69
84164 3020.00Sampler, US PS-69TM
84164 3021.00Sampler, US CS-77
84164 3022.00Sampler, US PS-82
84164 3023.00Sampler, US BMH-53
84164 3024.00Sampler, US BMH-53TM
84164 3025.00Sampler, US BM-54
84164 3026.00Sampler, US BM-54TM
84164 3027.00Sampler, US BMH-60
84164 3028.00Sampler, US BMH-60TM
84164 3029.00Sampler, US RBM-80
84164 3030.00US DH-48 TM
84164 3031.00US DH-48 TM W/ TEFLON GASKET AND NOZZLE
84164 3032.00US DH-59 TM
84164 3033.00US DH-59 TM W/ TEFLON GASKET AND NOZZLE
84164 3034.00US DH-76 TM
84164 3035.00US DH-76 TM W/ TEFLON GASKET AND NOZZLE
84164 3036.00US D-74 TM
84164 3037.00US D-74 AL-TM
84164 3038.00US D-74 AL-TM W/ TEFLON GASKET AND NOZZLE
84164 3039.00US D-77 TM
84164 3040.00US D-77 TM MODIFIED TEFLON BAG SAMPLER
84164 3041.00US P-61 AL-TM
84164 3042.00US P-61
84164 3043.00US P-61 TM
84164 3044.00US DH-81
84164 3045.00US DH-81 WITH TEFLON CAP AND NOZZLE
84164 3050.00TEFLON BAG SAMPLER
84164 3060.00WEIGHTED-BOTTLE SAMPLER
84164 3070.00GRAB SAMPLE
84164 4010.00THIEF SAMPLER
84164 4020.00OPEN-TOP BAILER
84164 4025.00DOUBLE-VALVE BAILER
84164 4030.00SUCTION PUMP
84164 4035.00CENTRIFUGAL PUMP
84164 4040.00SUBMERSIBLE PUMP
84164 4041.00SUBMERSIBLE HELICAL ROTOR PUMP
84164 4045.00SUBMERSIBLE GEAR PUMP
84164 4050.00SQUEEZE PUMP
84164 4060.00GAS RECIPROCATING PUMP
84164 4070.00GAS LIFT
84164 4075.00PISTON PUMP
84164 4080.00PERISTALTIC PUMP
84164 4090.00JET PUMP
84164 4095.00LINE-SHAFT TURBINE PUMP
84164 8000.00NONE
84164 8010.00OTHER
8. Storage of Sampling Method in Data Base
Data analysis requires as much knowledge about a sample as possible.
Information on the method used to collect the sample is very useful.
SAMPLING METHOD is to be stored under parameter code 82398. Values for
this code are given below.
10.00EQUAL WIDTH INCREMENT (EWI)
20.00EQUAL DISCHARGE INCREMENT (EDI)
25.00TIMED SAMPLING INTERVAL
30.00SINGLE VERTICAL
40.00MULTIPLE VERTICALS
50.00POINT SAMPLE
60.00WEIGHTED BOTTLE
70.00GRAB SAMPLE (DIP)
90.00DISCHARGE INTEGRATED, CENTROID
120.00VELOCITY INTEGRATED
8010.00OTHER
9. Storing Sample Purpose Code in Data Base
A value for parameter code 71999 (Sample Purpose Code) is to be stored
with all HBN samples. The following value is to be used:
30.00 = Benchmark
Use of this code will allow identification and retrieval of Network
samples for data analysis. If samples are collected at Benchmark stations
for purposes other than National Network operations, the sample purpose
code should not be 30.00.
10. Preservatives
The only preservative now required for National Network samples is nitric
acid for the FA bottle. For schedules 176 and 177, The 1-mL glass or
teflon ampoules containing ultrapure nitric acid are to be used. Handle
ampoules carefully and dispose of them according to the method outlined
in OWQ Tech Memos 90.01 and 92.11. This will reduce potential sample
contamination. If a sample processing chamber is being used, the nitric
acid preservation can be done in the chamber after all sample processing
is completed. The chamber bag should then be disposed of.
11. Shipping Samples
Bottles for nutrient analyses (RCC and FCC -- 125 mL brown bottles) are
to be shipped to the National Water Quality Laboratory in a cooler with
plenty of fresh ice. The cooler should be lined with a plastic bag that
is then tied or sealed at the top to prevent leakage. The nutrient
samples are to be shipped to the lab immediately after sample collection,
preferably from the field, by overnight delivery. The Analytical Services
Request Form should be sealed in a zip-lock bag and included in the
cooler (taped to the inside of the lid) with the sample bottles. A
postcard requesting the arrival date and temperature of the sample can be
placed in the zip-lock bag. Lab personnel will fill out the information
and return the postcard to the District. This will enable you to
determine that the samples remained chilled to about 4 degrees Celsius
during shipping.
Although it is no longer necessary to separate the nutrient samples from
other samples, all other samples can be shipped unchilled in a cooler or
box. Make sure that each container has a separate Analytical Services
Request Form (ASR). The latest revision of the ASR is in tablets with a
blue cover. Books (of 50) forms can be obtained by sending edoc to
DENSUPPL. There is no charge for the forms. Older versions of the ASR
should not be used.
Shipping charges are paid by the Districts, either directly or billed by
the laboratory. Information on shipping samples is contained in a
memorandum dated September 17, 1991, from the Assistant Chief Hydrologist
for Operations. A copy can be obtained from your District administrative
officer.
12. Bottle Types
Following is a list of bottle types and the analyses that are done from
each. Individuals processing Network samples should be aware of this
information as means of preventing sample contamination. Note that the
FAM bottle will not be required again this year.
Schedule 86 - Nutrients
FCC - 125 mL, brown poly, filtered, chilled to 4oC
Nitrogen, dissolved, NO2 + NO3 as N (00631)
Nitrogen, dissolved, NH4 as N (00608)
Nitrogen, dissolved, NO2 as N (00613)
Phosphorus, dissolved, ortho as P (00671)
Phosphorus, dissolved as P (00666)
RCC - 125 mL, brown poly, chilled to 4oC
Nitrogen, total, NH4 + organic as N (00625)
Phosphorus, total as P (00665)
Schedule 1703 - Radiochemicals
FAR - 2 L poly, acid rinsed, filtered, treated with 2 mL nitric acid
(or amount necessary to obtain pH <2)
Radium-226, dissolved (09511)
Uranium, dissolved, ext, LIP, FF (22703)
Schedule 176 - Physical properties, common and trace dissolved inorganic
constituents
FA - 250 mL poly, filtered, treated with 1 mL nitric acid (glass
ampoule)
(or amount necessary to obtain to pH <2)
Aluminum (01106) Molybdenum (01060)
Barium (01005) Nickel (01065)
Calcium (00915) Potassium (00935)
Cobalt (01035) Selenium (01145)
Iron (01046) Silver (01075)
Lithium (01130) Sodium (00930)
Magnesium (00925) Strontium (01080)
Manganese (01056) Vanadium (01085)
FU - 500 mL poly, filtered, untreated
Silica (00955)
Sulfate (00945)
Fluoride (00950)
Chloride (00940)
ROE at 180 C (70300)
LC00050 - 125 mL poly, untreated
Turbidity, NTU (00076)
RU - 250 mL poly, untreated
pH, laboratory (00403)
Specific conductance, laboratory (90095)
Alkalinity, total, laboratory (00417)
Schedule 177 - Physical properties, common and trace dissolved inorganic
constituents
FA - 500 mL poly, filtered, treated with 2 mL nitric acid (glass
ampoule)
(or amount necessary to obtain to pH <2)
Aluminum (01106) Molybdenum (01060)
Barium (01005) Nickel (01065)
Calcium (00915) Potassium (00935)
Cobalt (01035) Selenium (01145)
Iron (01046) Silver (01075)
Lithium (01130) Sodium (00930)
Magnesium (00925) Strontium (01080)
Manganese (01056) Vanadium (01085)
FU - 500 mL poly, filtered, untreated
Silica (00955)
Sulfate (00945)
Fluoride (00950)
Chloride (00940)
ROE at 180 C (70300)
LC0050 - 125 mL poly, untreated
Turbidity, NTU (00076)
RU - 250 mL poly, untreated
pH, laboratory (00403)
Specific conductance, laboratory (90095)
Alkalinity, total, laboratory (00417)
13. Water-Quality Field Techniques References
Below is a list of Office of Water Quality Technical Memoranda and
additional references that describe the techniques that are to be used in
the collection and processing of water-quality samples. These references
should be available to all people collecting water- quality samples.
Office of Water-Quality Technical Memoranda
Number Date Subject
70.07 11-28-69 Quality control of water analyses: water-quality
service units and mobile laboratories
71.04 1-13-71 Methods for collection and analysis of water samples
for dissolved minerals and gases (TWRI book 5, Ch. A1)
71.05 3-18-71 Sampling and analysis of water-quality constituents
associated with suspended solids
71.09 6-22-71 Guidelines for sampling and analysis of water-quality
constituents associated with solids
72.04 11-08-71 Instructions for use of sediment samplers for the
collection of samples to be analyzed for organic
substances
72.09 1-05-72 Preservation of water samples for chemical analysis
(superceded by 80.26)
72.13 2-28-72 Computations of fluvial-sediment discharge (TWRI book
5, Ch. C3)
73.02 9-11-72 Field determinations (superceded by 82.06)
73.07 10-26-72 Teflon sample splitters and plastic sleeves
73.16 4-23-73 Sampling procedures and problems in determining
pesticide residues in the hydrologic environment
74.11 2-28-74 Field instruction for NASQAN
75.09 12-26-74 Acceptable methods for collection of water-quality
data
75.15 3-13-75 Publication of water temperatures
75.25 6-19-75 Guidelines on sampling and statistical methodologies
for ambient pesticide monitoring
76.03 10-14-75 Water-quality field instrumentation
76.17 5-12-76 Sampling mixtures of water and sediment in streams
76.24-T 8-16-76 Sample splitter for water-sediment samples
77.01 12-13-76 Sample splitter for water-sediment samples (cleaning
instructions) (supplements 76.24T)
77.03 1-17-77 DH-75 suspended-sediment sampler
77.07 4-06-77 Guidelines for application of Helley-Smith bedload
sampler
77.08 5-06-77 Relationship of sediment discharge to streamflow
78.03 1-17-78 Churn splitters (supplements 76.24T and 77.01)
78.06 4-05-78 Field filtering of water samples for chemical analyses
78.13 7-10-78 Microbiological monitoring for water-quality
assessment
79.06 12-11-78 Shipment of hazardous material
79.08 3-07-79 Modification of the field chamber for the YSI
dissolved oxygen meter
79.10 3-14-79 Recommended procedures for calibrating dissolved
oxygen meters
79.15 9-11-79 Data networks; unique number identification for
federally funded stations
79.16 9-28-79 Quality assurance of temperature measurements
79.17 10-02-79 Use of Helley-Smith bedload sampler
80.03 11-19-79 Samplers--P-61 and P-63 point-integrating sediment
samplers
80.06 1-24-80 Color-coded nozzles for sediment samplers
80.07 2-05-80 Use of Helley-Smith sampler
80.16 6-02-80 Quality assurance program for sediment laboratories
80.17 7-03-80 New sample splitter for water-quality samples (cone
splitter)
80.18 6-13-80 Samplers-- problems with installation of plastic
nozzles on samplers
80.26 9-19-80 Preservation of nutrient samples by addition of
mercuric chloride
80.30 9-23-80 Significance of bottom material data in evaluating
water quality
81.02 10-16-80 Operation and availability-- D-77 water-quality
sampler
81.08 2-10-81 Electrodes for pH measurement in low-conductivity
waters
81.11 5-08-81 New tables of dissolved oxygen saturation values
82.01 10-27-81 Collecting water samples for stable isotope analysis
82.05 12-11-81 Provisional method for carbonate, dissolved;
bicarbonate, dissolved; and carbonate alkalinity,
dissolved; electrometric titration, incremental, field
82.06 1-22-82 Policy on publishing constituents with both field and
laboratory values
84.04 11-30-83 Technical information: briefing paper on mercury
84.18 9-28-84 Preservation and shipment of water samples for
determination of mercury
87.03 2-12-87 pH measurement in low conductivity waters
90.01 10-03-89 Sample preservation and ampoule disposal
90.07 2-02-90 Contamination from D-77 sampler equipped with
solenoid-actuated valves
91.01 10-29-90 "Methods for collection and analysis of aquatic
biological and microbiological samples," by L.J.
Britton and P.E. Greeson, editors, Techniques
Water-Resources Investigations (TWRI), Book 5,
Chapter A4
91.02 12-05-90 "Methods for collection and processing of
surface-water and bed-material samples for physical
and chemical analysis," by Janice R. Ward and C.
Albert Harr, editors, Open-File Report 90-140
91.04 2-08-91 Office of Water Quality electronic memorandum system
91.08 8-07-91 "A primer on sediment-trace element chemistry"
(second edition), by Arthur J. Horowitz
91.09 8-27-91 "Filtration of water-sediment samples for
determination of organic compounds," by Mark W.
Sandstrom
91.10 9-30-91 Dissolved trace element data
92.01 12-20-91 Distilled/deionized water for District operations
92.02 12-20-91 Field preparation of containers for aqueous samples
92.04 3-20-92 Revised statement regarding dissolved trace-element
data production
92.05 3-20-92 Quality of existing dissolved trace-element data
92.06 3-20-92 Report of committee on sample shipping integrity and
cost
92.08 3-27-92 Nutrient sample size reduction
92.10 7-13-92 Phosphorus methods and the quality of phosphorus data
92.11 7-16-92 Return of spent mercury and dichromate ampoules to
the National Water Quality Laboratory
92.12 7-17-92 Trace-element concentrations in deionized water
processed through selected surface-water samplers:
Study results and implications
92.13 7-17-92 Trace-element contamination: Findings of studies on
the cleaning of membrane filters and filtration
systems
93.01 10-05-92 National Water-Quality Networks: Fiscal year
1993--October 1, 1992 to September 30, 1993
93.03 10-29-92 Dissolved trace-element data
93.04 12-02-92 Discontinuation of the NWQL determinations for "total"
nitrite, "total" nitrite plus nitrate, "total"
ammonia, and "total" orthophosphate (using the
four-channel analyzer)
93.05 1-21-93 Evaluation of capsule filters
93.06 2-19-93 Trace-element contamination--Findings of study on the
cleaning of sampler caps, nozzles, bottles, and bags
for trace-element work at the part-per-billion level
93.09 4-16-93 Sample splitting devices
93.10 4-91-93 (1) Disposal of petri dishes containing bacteria
media, and (2) aspergillus
93.11 7-15-93 Implementation of the protocol for collecting and
processing surface-water samples for low-level
inorganic analyses
94.02 11-22-93 Discontinuance of field use of mercury liquid-in-glass
thermometers
94.06 1- 3-94 New custom analysis schedule (172) for blanks
94.09 1-28-94 Revision of new Division protocol for collecting and
processing surface-water samples for low-level inorganic
analyses
94.12 4-20-94 Changes in schedule 172
94.13 4-21-94 Evaluation of the churn splitter for inclusion in the
Division protocol for the collection and processing of
surface-water samples for subsequent determination of
trace elements, nutrients, and major ions in filtered
water
94.16 8- 5-94 New preservation techniques for nutrient samples
Additional References
Barnes, Ivan, 1964, Field measurement of alkalinity and pH:
U.S. Geological Survey Water-Supply Paper 1535-H, 17 p.
Britton, L.J., and Greeson, P.E., eds, 1989, Methods for collection and
analysis of aquatic biological and microbiological samples:
U.S. Geological Survey Techniques of Water Resources Investigations,
book 5, chap. A4, 363 p.
Busenberg, Eurybiades, and Plummer, L.N., 1987, pH measurement of
low-conductivity waters: U.S. Geological Survey Water-Resources
Investigations Report 87-4060, 22 p.
Edwards, T.K., and Glysson, G.D., 1988, Field methods for measurement of
fluvial sediment: U.S. Geological Survey Open-File Report 86-531,
188 p.
Guy, H.P., and Norman, V.M., 1970, Field methods for measurement of
fluvial sediment: U.S. Geological Survey Techniques of Water Resources
Investigations, book 3, chap. C2, 59 p.
Hem, J.D., 1985, Study and interpretation of chemical characteristics of
natural water: U.S. Geological Survey Water-Supply Paper 2254, 263 p.
Stevens, H.H., Jr., Ficke, J.F., and Smoot, G.F., 1975, Water
temperature--influential factors, field measurement, and data
presentation: U.S. Geological Survey Techniques of Water Resources
Investigations, book 1, chap. D1, 65 p.
Sylvester, M.A., Kister, L.R., and Garrett, W.B.,eds, 1990, Guidelines
for the collection, treatment, and analysis of water samples--U.S.
Geological Survey Western Region field manual: U.S. Geological Survey,
Western Region, internal report, 144 p.
Ward, J.R., and Harr, C.A., eds, 1990, Methods for collection and
processing of surface-water and bed-material samples for physical and
chemical analyses: U.S. Geological Survey Open-File Report 90-140,
71 p.
Wells, F.C., Gibbons, W.J., and Dorsey, M.E., 1990, Guidelines for
collection and field analysis of water-quality samples from streams
in Texas: U.S. Geological Survey Open-File Report 90-127, 79 p.
Wood, W.W., 1976, Guidelines for collection and field analysis of
ground-water samples for selected unstable constituents: U.S.
Geological Survey Techniques of Water Resources Investigations, book 1,
chap. D2, 24 p.
Yurewicz, M.C., 1981, Incremental field titration of bicarbonate: U.S.
Geological Survey Water Resources Division Bulletin, October-December
1981, (for WRD use only), p. 8-13.
Collection of Representative Samples
As in past years, the Office of Water Quality reminds all field personnel
that the collection of a representative sample is of utmost importance.
Procedures for the collection of a representative sample are well
documented. As part of this effort, cross-section surveys (depth and
width) of water temperature, pH, specific conductance, dissolved oxygen,
and suspended sediment have been required activities at each site in the
two networks. Over a period of years the data base of such data should
include observations for various seasons and surface-water discharges.
Cross-section surveys should include a discharge measurement so that each
measured constituent can be associated with a weighted discharge value.
The results of cross-section surveys should be stored in the
WATSTORE/NWIS Water-Quality File. When entering such data, be sure to
enter the cross section location - WATSTORE code 00009, CROSS-SECTION
LOCATION, FEET FROM LEFT BANK, LOOKING DOWNSTREAM.
Contamination of trace-element samples in the field has become an
important issue as laboratory methods continue to improve and reporting
limits are lowered. Therefore, all individuals who are collecting
water-quality samples need to be aware of the importance of keeping
equipment and field vehicles clean and of using proper care when
collecting and handling samples. All sampling equipment is to be
thoroughly cleaned (the cleaning procedures are described in detail in
Appendix D of this memo). Churn splitters and other equipment are to be
stored in sealed plastic bags after they are cleaned and until they are
used. Sample water should be poured carefully into the churn so that the
water does not come into contact with hands or the cover of the churn.
The churn is to be kept covered, when water is not being added to it (or
modify the churn splitter by adding a cappable funnel as described in OWQ
Technical Memorandum 94.09). In order to keep dirt off the outside of the
churn, and dust from getting into the churn, it should be kept in a
plastic bag which is opened only to allow access to the churn for
emptying the sampler bottle. The "clean hands/dirty hands" technique is
suggested where the "clean hands" person wears disposable gloves and
handles only the sample bottle and the "dirty hands" person handles the
sampling equipment (metal part of the sampler, reel, etc.) The "clean
hands" person is careful not to touch metal objects or anything that
could contaminate the sample, and changes gloves whenever this type of
contact occurs.
Sample processing should be done inside the vehicle and away from dust
and exhaust. Best results are obtained when samples are processed in a
clean, metal-free chamber (a glove box or chamber built from wood and
plexiglass). All bottles are to be stored in clean areas and uncapped
bottles (other than the untreated bottles) should be discarded. Untreated
bottles are to be rinsed with sample water (filtered water for filtered
samples and unfiltered water for unfiltered samples), as described in OWQ
Technical Memorandum 92.02. Disposable gloves are to be worn when
handling preservatives (and changed between different types of
preservatives), and when processing bacteria samples.
Periods for Sample Collection
The table below indicates the time periods for sample collection for
stations sampled quarterly (four times per year). Sample collection
frequencies for FY 1995 are shown in Appendix A. In order for the data to
meet the objectives of the Benchmark program, it is important that the
sampling schedule be adhered to.
QUARTERLY STATIONS
first sample OCTOBER-NOVEMBER-DECEMBER
second sample JANUARY-FEBRUARY-MARCH
third sample APRIL-MAY-JUNE
fourth sample JULY-AUGUST-SEPTEMBER
Use of ICP
The inductively-coupled plasma (ICP) procedure is used for the analysis
of selected dissolved common and trace inorganic constituents. The ICP
procedure is not to be used whenever the specific conductance is greater
than 2,000 uS/cm because the detection limits become greater. Schedule
177 will be used in lieu of schedule 176 whenever the specific
conductance is greater than 2,000 uS/cm. Based upon historical specific
conductance data for each NASQAN and HBN Station, the percentage of
samples with specific conductance values equal to or greater than 2,000
uS/cm was computed and is given in Appendix A under the right-hand
heading "PROBABILITY (%) THAT SPECIFIC CONDUCTANCE WILL BE EQUAL TO OR
GREATER THAN 2,000 US/CM." These probabilities indicate the expected
frequency of use schedule 177 will get at each site over a long period of
time. Determination of specifically which schedule to request for a
sample is based on the specific conductance value measured at the time of
sampling.
Only schedule 176 is authorized for stations with zero probability of the
specific conductance exceeding 2,000 uS/cm. Because of the uncertainty
involved in predicting the number of samples that will exceed 2,000
uS/cm, both schedule 176 and 177 are authorized for four uses at HBN
stations where the value given in the right-hand column of Appendix A is
greater than zero. The actual number of usages authorized between
schedules 176 and 177 is however four, not eight.
District Water-Quality Specialists have the authority and responsibility
to request schedules 176 versus schedule 177. Because use of schedule 176
versus 177 is dependent solely upon the specific conductance of the
sample, District Water-Quality Specialists should ensure that all field
personnel are aware that a field specific conductance measurement is
absolutely necessary whenever schedule 176 or 177 is to be utilized.
Unique Numbers
Districts are reminded that all samples (excluding suspended-sediment
samples which are analyzed in District sediment laboratories for particle
size and concentration) are to be sent to the U.S. Geological Survey
National Water-Quality Laboratory in Arvada, CO, with appropriate
National Laboratory unique numbers. Unique numbers are described in
Quality of Water Branch Technical Memorandum 79.15 and can be obtained by
station number through the SPN system on DCOLKA. New unique numbers are
established at the beginning of the each water year and are to be used
until September 30 of each water year. Personnel collecting HBN samples
should keep a current listing of the unique numbers in their field
folders.
Any National-Networks sample processed by the National Water Quality
Laboratory without a unique number will result in the analytical costs
being billed to the District default account instead of the appropriate
National-Networks account. Correcting such billing errors after they
occur requires a memorandum to the Coordinator, National Hydrologic
Benchmark Program.
Analytical Services Request Form
Although the unique number, date, and time are all that are required on
the Analytical Services Request Form, additional information such as
station name, special sampling conditions, National-Networks program
(Benchmark), etc., are helpful to the National Water Quality Laboratory
personnel and District personnel processing the analytical results. All
information coded in the comments section of the Analytical Services
Request Form is stored in the Water-Quality File.
Uniform Data-Collection Program
Districts are reminded of the importance to ensure that all HBN samples
be analyzed for the same measurements as specified later in this
memorandum. In particular, all field measurements specified have to be
done for every sample.
HYDROLOGIC BENCHMARK DATA COLLECTION PROGRAM
Hydrologic Benchmark Network stations to be operated in FY 1996 are
listed in Appendix A. Rain gages were installed at a number of stations
during FY 1994. The rain gages should collect precipitation data at the
same frequency as the stream gage. Changes in locations of sampling sites
must be approved by the National Networks Coordinator.
All HBN stations will be sampled quarterly. Schedule 1904 will no longer
be used. Analysis of radiochemicals will be on a semiannual basis (1
high-flow and 1 low-flow sample).
The specific conductance is likely to exceed 2,000 uS/cm at only one HBN
station - the Bear Den Creek at Mandaree, ND (06332515). Therefore, this
station may require schedule 177 for analysis of quarterly dissolved
common and trace inorganic constituents. All other stations will require
use of schedule 176 for analysis of these constituents.
HBN Sampling Schedule for FY 1996
Please notify the Office of Water Quality if the District responsible for
collection of samples for any HBN station has changed recently and is
therefore incorrectly listed in Appendix A.
Hydrologic Benchmark Network Sampling Schedule
4 per year - Field Measurements:
Instantaneous discharge (WATSTORE Code 0006l)
Specific conductance (WATSTORE Code 00095)
Water temperature, degrees C (WATSTORE Code 00010)
Barometric pressure, mm Hg (WATSTORE Code 00025)
pH (WATSTORE Code 00400)
Carbonate, water, dissolved, mg/L (WATSTORE Code 00452)
Bicarbonate, water, dissolved, mg/L (WATSTORE Code 00453)
Alkalinity, water, dissolved, as CaCO3, mg/L
(WATSTORE Code 39086)
Hydroxide, water, dissolved, mg/L (WATSTORE Code 71834)
Dissolved oxygen (WATSTORE 00300)
Fecal coliform bacteria, 0.7 um (WATSTORE Code 31625)
Fecal streptococcal bacteria, 0.45 um (WATSTORE Code 31673)
4 per year - Suspended sediment:
Concentration (WATSTORE Code 80154)
Percent finer than 0.062 mm, sieve diameter
(WATSTORE Code 70331)
4 per year - Nutrients, lab schedule 86
4 per year - Physical properties, common and trace dissolved
inorganic constituents: lab schedule 176
2 per year - Radiochemicals, lab schedule 1703
Cross-section surveys (depth and width) of temperature, pH, specific
conductance, dissolved oxygen, and suspended-sediment concentration as
needed to document cross-section homogeneity.
If any information in this memorandum prompts questions or comments,
please call Kathy Fitzgerald whose current number is (703) 648-6902.
Janice R. Ward
for David A. Rickert
Attachments
This memorandum supersedes OWQ Technical Memorandum 95.01.
Distribution: A, B, S, FO, PO
Key Words: water quality, networks, sampling, Benchmark, FY 1996
APPENDIX A
This appendix contains the listing by District of all HBN stations.
Copies of the appendix may be retrieved via anonymous ftp by issuing the
following commands:
ftp 130.11.50.18
login: anonymous
password: your userid
cd pub/benchmark
type binary
get appendix.a.96.fm/
bye
This is a Framemaker 4.0 file. It must be opened in Framemaker to be
printed. Choose the landscape option for printing.
APPENDIX B
NUTRIENTS
SCHEDULE 86 WN OWNER:NQ
COST: 77.80 CALCULATED
LAB WATSTORE
CODE CODE INCLUDED PARAMETERS
1688 00625 A NITR. NH4+ORG AS N WWR
1685 00666 B PHOSPHORUS, DIS. JKA
1686 00665 B PHOSPHORUS, TOTAL JKA
0160 00613 B NITR DIS NO2 AS N
0162 00671 B PHOS DIS ORTHO AS P
0301 00608 B NITR DISS NH4 AS N
0228 00631 B NITR DIS NO2+NO3 -N
REQUIRES
0125 ml OF FCC
0125 ml OF RCC
RADIOCHEMICALS
SCHEDULE 1703 WR OWNER:NQ
COST: 305.00 FIXED
LAB WATSTORE
CODE CODE INCLUDED PARAMETERS
0794 09511 B RADIUM-226, DISS. RN
1386 22703 E U.DIS,EXT,LIP,FF
REQUIRES
0002 liters OF FAR
PHYSICAL PROPERTIES, COMMON AND TRACE DISSOLVED INORGANIC
CONSTITUENTS
SCHEDULE 176 WI OWNER:NQ
COST: 256.30 FIXED
LAB WATSTORE
CODE CODE INCLUDED PARAMETERS
0027 70300 A ROE, DISS. AT 180 C
0050 00076 A TURBIDITY (NTU)
0054 00935 B POTASSIUM, DISSOLVED
0068 00403 A PH (LABORATORY)
0069 90095 A SP. CONDUCTANCE LAB
0070 90410 A ALK TOT LAB. CACO3
0087 01145 A SELENIUM, DISSOLVED
0641 01005 C BARIUM, DISSOLVED
0644 01035 C COBALT, DISSOLV.
0645 01046 D IRON, DISSOLV.
0648 01056 C MANGANESE, DISSOLVED
0649 01060 A MOLYBDENUM, DISS.
0652 01080 B STRONTIUM, DISSOLVED
0653 01085 B VANADIUM, DISSOLVED
0659 00915 D CALCIUM, DISSOLVED
0663 00925 C MAGNESIUM, DISSOLVED
0664 01130 B LITHIUM, DISSOLVED
0667 00955 D SILICA, DISSOLVED
0675 00930 C SODIUM, DISSOLVED
1284 01106 E ALUMINUM-DIS-DCP
1552 01075 F SILVER GFAA DIS
1562 01065 F NICKEL GFAA DIS
1571 00940 J CHLORIDE DIS IC
1572 00945 G SULFATE DIS IC
1573 00950 E FLUORIDE DIS IC
REQUIRES
0250 ml OF FA
0250 ml OF RU
0125 ml OF LC0050
0500 ml OF FU
SCHEDULE 177 WI OWNER:NQ
COST: 318.40 CALCULATED
LAB WATSTORE
CODE CODE INCLUDED PARAMETERS
0007 01005 B BARIUM, DIS.
0012 00915 C CALCIUM, DISSOLV.
0027 70300 A ROE, DISS. AT 180 C
0039 01130 A LITHIUM, DISSOLV.
0040 00925 B MAGNESIUM, DISSOLV.
0042 01056 A MANGANESE, DISSOLV.
0050 00076 A TURBIDITY (NTU)
0054 00935 B POTASSIUM, DISSOLVED
0056 00955 C SILICA, DIS.
0059 00930 B SODIUM, DIS.
0062 01080 A STRONTIUM, DIS.
0068 00403 A PH (LABORATORY)
0069 90095 A SP. CONDUCTANCE LAB
0070 90410 A ALK TOT LAB. CACO3
0087 01145 A SELENIUM, DISSOLVED
0110 01060 B MOLYBDENUM, DISSOLV.
0172 01046 C IRON, DIS.
1210 01085 D VANADIUM, DIS. AUTO.
1284 01106 E ALUMINUM-DIS-DCP
1552 01075 F SILVER GFAA DIS
1556 01035 F COBALT GFAA DIS
1562 01065 F NICKEL GFAA DIS
1571 00940 J CHLORIDE DIS IC
1572 00945 G SULFATE DIS IC
1573 00950 E FLUORIDE DIS IC
REQUIRES
0500 ml OF FA
0250 ml OF RU
0125 ml OF LC0050
0500 ml OF FU
APPENDIX C
ALKALINITY - INCREMENTAL TITRATION METHOD
Hach Titrator
INTRODUCTION
Alkalinity is a measure of the buffering capacity of water against acid.
Degasification, precipitation, and other chemical and physical reactions
may cause the concentrations of carbonate and bicarbonate to change
substantially within several hours or even minutes after sample
collection. Consequently, field values for carbonate and bicarbonate or
alkalinity usually are more reliable than values obtained in the
laboratory (Wells and others, 1990).
Particulates can take up some strong acid by dissolution, adsorption, or
ion exchange and, thereby, cause anomalously high measurements. For this
reason, filtration through a 0.45 micron pore-size filter is required. In
order to prevent contamination by wind-borne dust and loss of carbon
dioxide due to warming by the sun, the analysis should be done in an
enclosed vehicle (OWQ Technical Memorandum 82.05).
APPARATUS
1. pH meter with combination pH probe or equivalent.
2. Hach digital titrator.
3. Titrant acid cartridges (0.16 and 1.6 N) with straight- or bent-tube
delivery tubes.
(NOTE: Clear delivery tubes are now available from Ocala)
4. Magnetic stirrer.
5. Deionized water.
6. 50 mL and 100-mL volumetric pipets.
METHOD
1. Select the appropriate strength titrant, 0.1600 Normal (N) or 1.600N
sulfuric acid, and sample volume from the following table, based on the
expected alkalinity. Record the acid normality and sample volume on the
field sheet.
Expected Alkalinity Sample Volume Acid Normality
<20 100 0.1600
20-50 50 0.1600
50-150 100 1.600
>150 50 1.600
NOTE: The volumes and acid normalities in the above table are guidelines
only. Inflection points will be better defined by using the 0.1600
N acid.
2. Assemble the digital titrator:
a) Insert the appropriate cartridge into the titrator and turning it
1/4 turn to lock it in position.
b) Remove the vinyl cap and insert a delivery tube into the cartridge
tip. Delivery tubes cannot be interchanged between different
normality cartridges and should be identified to avoid
cross-contamination.
c) Flush the tube by turning the delivery knob to release some of the
titrant into a waste container. Make sure that a sufficient amount
is released to assure that there are no bubbles or water in the
tube.
d) Gently blot any droplets that adhere to the end of the tube and
set the digital counter reading to ZERO.
3. Use a clean volumetric pipet or cylinder, rinse with sample water, and
measure the appropriate sample volume into a clean beaker containing a
Teflon-coated stirring bar.
4. Place rinsed pH probe (previously rinsed with sample water) into the
sample and place the beaker on a magnetic stirrer.
5. Turn on stirrer and adjust stirring rate to LOW. Sample should be
GENTLY stirred throughout the titration. Turn on pH meter, allow reading
to stabilize and then read and record the initial pH value.
6. If sample pH is less than 8.3, then skip the next step (7).
7. If sample pH is greater than 8.3, add sulfuric acid by small
increments (1 to 3 digital counts at a time) until the pH is less than
8.0. The tip of the delivery tube should be below the sample surface
(keep the tube clean to avoid contamination of the sample). Allow 15-20
seconds for equilibration between incremental additions of acid. Record
pH and digital counter reading after each addition of acid.
8. Titrate rapidly to pH 5.0 (5.5 for alkalinities of <20 mg/L). The tip
of the delivery tube should be below the sample surface (keep the tube
clean to avoid contamination of the sample). Allow 15-20 seconds for
equilibration and record the digital counter reading.
9. From pH 5.0 (5.5) to 4.0, add acid by small increments (1 to 3 digital
units at a time). Allow 15-20 seconds for equilibration between
incremental additions of acid and record pH and digital counter reading
after each addition of acid.
10. Calculations: (initial calculations should be done in the field)
(a) Calculate the change in pH and the change in counter numbers and
record these values on the field sheet.
(b) Divide each change in pH by the change in the counter numbers
and record the results on the field sheet.
(c) The endpoints are the counter numbers where the maximum rates of
change in pH per counter number increments occur. If a tie for
the end point occurs, choose the last one (the one with the
lower pH).
(d) Calculate carbonate (00452).
CO3 (mg/L as CO3) = A x F1/mL sample
(e) Calculate bicarbonate (00453).
HCO3 (mg/L as HCO3) = [B - 2(A)] x F2/mL sample
(f) Calculate total alkalinity (39086).
Total Alkalinity = B x F3/mL sample
where:
A = digital count from initial pH to endpoint near 8.3
B = digital count from initial pH to endpoint near 4.5
0.1600N 1.600N
F1 12.0 120
F2 12.2 122
F3 10.0 100
After completing the titration, remove the cartridge from the titrator
and replace the vinyl cap immediately to avoid exposure of the contents
to the air. Rinse the delivery tube with distilled water and blow out the
remaining water with a syringe to avoid starting the next titration with
water. Store the delivery tubes in a clean plastic bag.
REPORTING
Report total alkalinity, carbonate, and bicarbonate concentrations as
follows: less than 1,000 mg/L, to whole numbers; 1,000 mg/L and above,
three significant figures.
REFERENCES
Barnes, Ivan, 1964, Field measurement of alkalinity and pH:
U.S. Geological Survey Water-Supply Paper 1535-H, 17 p.
Quality Water Service Unit, 1990, Water-quality field techniques:
U.S. Geological Survey, Florida District, internal document, 164 p.
Sylvester, M.A., Kister, L.R., and Garrett, W.B., eds, 1990, Guidelines
for the collection, treatment, and analysis of water samples--U.S.
Geological Survey Western Region field manual: U.S. Geological Survey,
Western Region, internal document, 144 p.
Wells, F.C., Gibbons, W.J., and Dorsey, M.E., 1990, Guidelines for
collection and field analysis of water-quality samples from streams
in Texas: U.S. Geological Survey Open-File Report 90-127, 79p.
Branch of Water Quality Technical Memorandum 82.05: December 11, 1981.