Office of Water Quality Technical Memorandum 2002

Constituents Measured

Constituents measured at NASQAN stations vary somewhat across the country depending on local conditions. Major ions and nutrients (including carbon species) are measured at all NASQAN stations. Both dissolved and sediment-associated trace elements were measured at many stations in the Colorado, Columbia, Mississippi, and Rio Grande basins during 1996-2000; sampling for these constituents continues only at stations that were not well sampled during this period (including new stations in these basins and in the Yukon basin) and at a subset of stations in these basin at a reduced frequency. Pesticides (NWQL Schedule 2001) are measured throughout the Mississippi and Rio Grande basins; but are not measured in the Yukon basin. Radiochemistry is measured in the Colorado and Yukon basins.

Special Studies

Mississippi Basin

The water-quality issues in the Mississippi River Basin are complex and varied, including changing the operation of the dams on the Missouri River to provide habit for endangered species, survival of the mussel population during the building of a lock and dam on the lower Ohio River and the effects of the Spring 2001 upper Mississippi River flood. Currently, the most prominent water-quality issue in the Mississippi River Basin, on a national scale, is the hypoxic waters that form near shore in the Gulf of Mexico each summer. The areal extent of these hypoxic waters in July 2001 was about 8,000 square miles; this is the maximum extent recorded since record keeping began in the early 1980’s. Some researchers relate the increase in nitrogen being discharged from the Mississippi River over the past 50 years to the growth and severity of these hypoxic waters. Although, the NASQAN program will not answer the question of whether the increased nitrogen exacerbates the hypoxic waters, the program with its flux-based approach will provide information on source areas for nutrients and document any changes in the transport of nutrients that might occur in an effort to control the hypoxic zone.

During FY 2002, the following special studies will continue in the Mississippi Basin:

· Stable Isotopes --The stable isotopic content of C, N, and S of particulate organic matter will be measured by Carol Kendall (NRP-WR). Preliminary data indicate that the POM may have a planktonic source, contrary to what was previously assumed. To test this hypothesis, chlorophyll-a will also be measured in the Mississippi Basin. (NASQAN contributes $20,000 for partial payment of lab analyses.)

· Tritium -- Samples will be collected for tritium analysis for Robert Michel (NRP, WR) at 3 stations (Ohio R. @ Cannelton Dam; Mississippi R. @ St. Francisville; Missouri R. @ Omaha). (NRP-WR at no cost to NASQAN)

· Time of travel – In FY 2002 an effort will be made to gather the literature on the time of travel of a parcel of water in the Mississippi River Basin with an emphasis on the big rivers. This is prior to conducting new time of travel studies of the Mississippi River system. (Richard Rebich, MS District; $15,000)

· Cumberland River – The calculation of constituent yields in the lower Ohio River has shown some results, which are counter-intuitive. One of the areas of interest is the Tennessee-Cumberland system. Prior to 2001 only the Tennessee River was sampled and the yields for the Cumberland River were calculated by difference. Beginning in FY 2002 the Cumberland River near the confluence of the Ohio River will be added as a NASQAN station.

· LTRMP—NASQAN will be working during FY02 with BRD’s Long Term Resource Monitoring Program to ensure data comparability. A joint analysis of NASQAN, NAWQA, Co-op and LTRMP data is being explored to describe the water-quality effects of the spring 2001 flooding in the upper Mississippi River Basin. (Richard Coupe, Miss. Basin Coordinator, MS District; and Steve Kahlkoff, IA District, $20,000)

· Pool 8 GW/SW Interaction—Randy Hunt (WI District) will complete a multi-year study on groundwater/surface water interaction at Pool 8 on the Mississippi done in cooperation with BRD-LTRM (Onalaska, WI) and NRP-WR on nutrient budgets and processing in this navigation pool of the upper Mississippi River. ($20,000)

· Establishment of Baton Rouge “Supergage”—During FY02, NASQAN sampling will transition from the historical location at St. Francisville, LA to a new gage at Baton Rouge, LA that will include real-time water-quality monitoring. This activity is in support of Tulane University’s Lower Estuary Assessment Group. (Support for this activity is from the Toxics Program and by transferring resources from St. Francisville gage to new gage at Baton Rouge.)

· Lower Valley Synoptic Sampling. Plans are being made to conduct a one-time synoptic sampling of major tributaries and historic NASQAN stations from Memphis, TN to Vicksburg, MS to assess the contribution of lower valley directly rather than by difference between the loadings measured at St. Francisville and Melville and those measured at Thebes and Grand Chain. Sampling will be done in cooperation with NAWQA Mississippi Embayments Study Unit. (AR District, MS District, LA District, and Richard Coupe, $35,000)

· Modeling size and volume of hypoxic zone—Bill Battaglin (CO District) will work with Nancy Rabalais (Louisiana Universities Marine Consortium (LUMCON)) on determining volume (rather than just area) of hypoxic zone and explore the relation between this volume and nutrient loadings. ($37,000)

Rio Grande Basin

The Rio Grande forms the boundary between Mexico and the United States in Texas and often is the sole source of water for a number of communities on both sides of the border and a source of habitat for wildlife and endangered species. The region is mostly arid to semiarid and flow is controlled by numerous reservoirs in the basin. On the mainstem of the Rio Grande, Amistad International Reservoir and Falcon International Reservoir serve to subdivide the Rio Grande into discrete river systems with unique hydrologic, geologic, and chemical characteristics.

The NASQAN fixed-station network will continue to collect data from the eight (8) stations monitored in FY 2001: Rio Grande near Presidio (08374200), Rio Grande at Foster Ranch (08377200), Pecos River near Langtry (08447410), Rio Grande below Amistad Dam (08450900), Rio Grande near Laredo (08459200), Rio Grande below Falcon Dam (08461300), Arroyo Colorado near Harlingen (08470400), and Rio Grande near Brownsville (08475000). The goal of the fixed-network is to continue to collect samples using a flux-based approach over a range in stage. Sampling will be done on a routine basis at the eight (8) stations located in the middle and lower portions of the Rio Grande watershed because of infrequent storm events in the basin. Although sampling is planned on a regular basis, efforts will be made to sample at higher stages and during storm events if they occur. Samples from the upper Rio Grande watershed near El Paso will continue to be collected as part of the NAWQA program. In FY 2002, NASQAN will take on a greater role in sampling at the Rio Grande near Presidio site. This site, operated in cooperation with the National Park Service at Big Bend National Park, provides information on water quality downstream of the confluence of the Rio Conchos with the Rio Grande. The Rio Conchos is the largest freshwater inflow to the Rio Grande in Texas and inflow from the river has historically dominated flow in the middle Rio Grande Basin during the summer rainy season. In the Rio Conchos watershed, expanding agricultural, mining, and timber harvesting activities as well as urban and industrial development affect both the quantity and quality of the Rio Grande. For the lower Rio Grande basin, flow at the Rio Grande at Brownsville site (08475000) will be sampled on an event-only basis. Because of reduced flows in the Rio Grande resulting from the construction of a low-water dam and reduced inflows from tributaries, the Rio Grande flows into the Gulf of Mexico generally only during higher flows and most of the time a sample cannot be collected at the Brownsville site. Most of the base flow from the Lower Valley is diverted into the Arroyo Colorado and is discharged into the Laguna Madre. During FY2002, NASQAN will review the network design in the lower basin to determine if an additional monitoring station is needed further upstream to account for flow downstream of Falcon Reservoir.

Both water column and suspended sediment samples will be collected and analyzed at the fixed-network stations. Field parameters such as stream discharge, water temperature, pH, dissolved oxygen, and conductivity will be measured. Water samples will be analyzed for major ions, nutrients, trace metals, dissolved and suspended organic carbon, dissolved inorganic carbon, selected pesticides, and sediment concentration. Additionally, oxygen/deuterium and nitrogen isotope samples are collected for NRP. Suspended sediment samples will be collected at selected sites and analyzed for suspended trace elements.

Special studies in the Rio Grande Basin: Special studies in the Rio Grande Basin are designed to address issues and concerns that cannot be adequately characterized using the current fixed-station network of NASQAN. Concerns in the region include the increasing concentration of metals including arsenic and mercury, increasing salinity, and the presence of numerous pesticide and organic compounds, especially in the lower Rio Grande Valley.

An analysis of historical (1970’s to 1994) riverbed sediment data for the Rio Grande Basin showed increasing trends of mercury and selenium in the region between the Pecos River and Amistad International Reservoir. Sampling of Falcon and Amistad Reservoirs was conducted in FY2001 to assess the occurrence and distribution of total mercury and methylmercury in the water column and in fish tissue. Methylmercury, the most toxic form of mercury, is usually ingested and can affect the immune system and nervous system. Elemental mercury may be found in higher concentrations in areas such as mining sites, but is not as toxic as methylmercury. The sampling of the reservoirs and fish will provide additional information on the distribution and forms of mercury present in the Rio Grande Basin. NASQAN will provide $10,000 in FY 2002 to analyze the mercury data and publish the results of FY 2001 special study.

Drainage from abandoned mercury, silver, lead, and gold mines are a principal source of contaminants affecting the quality of the Rio Grande upstream of, and in, Big Bend National Park. The presence of trace elements of concern including arsenic, cadmium, chromium, copper, lead, selenium, silver, and thallium have been documented, as has increasing trends of mercury and zinc in the middle Rio Grande basin. In FY 2002, an assessment of the effects of historical mining on the middle Rio Grande is planned to take a closer look at the influence of abandoned mines on the quality of the soil, sediment, and water in middle Rio Grande Basin in and around Big Bend National Park in the United States and the adjacent Maderas del Carmen and Canon de Santa Elena Mexican Protected Areas in Mexico. As part of the assessment, soil samples will be collected from mine tailings in Mexico and the United States, water and sediment (bed and suspended) samples will be collected from tributaries in Mexico and the United States and from the Rio Grande. When possible, some sediment samples will be collected during or shortly after storm events in tributaries downstream of abandoned mines. The assessment will be conducted in cooperation with the National Park Service – Big Bend National Park, the Mexican Protected areas, the International Boundary and Water Commission, the Texas Natural Resource Conservation Commission, and the U.S. Environmental Protection Agency (EPA). Part of the assessment will be funded by a $10,000 grant from the National Park Service’s United States-Mexico Affairs Office (MEAF). NASQAN will provide $40,000 for the trace metal special study in FY 2002.

Salinity continues to be of major concern throughout the Rio Grande Basin. Extended periods of drought in recent years in conjunction with decreased inflows because of recently constructed reservoirs on watersheds in Mexico have contributed to increasing salinity levels in the middle Rio Grande Basin. Researchers at the Texas A&M University Agricultural and Research Center at El Paso have shown that salinity is increasing in the region around Presidio at an annual rate of 15 to 18 mg/L. An assessment is planned in FY2003 to collect information on possible source(s) and distribution of salinity in the Rio Grande Basin. If feasible, a water-quality monitor will be installed to continuously monitor change in salinity in the Rio Grande or the Pecos River near Amistad Reservoir.

In FY 2004, NASQAN-Rio Grande special studies will take a more in-depth look at the presence and distribution of organic compounds and pesticides in the basin. The Rio Grande is home to numerous parks and wildlife refuges (including Big Bend National Park, Laguna Atascosa National Wildlife Refuge, and Mexican Protected Areas) that compete for water with agricultural and industrial users in the region. Increasing urbanization in the basin has increased the use of pesticide and organic compounds. The NASQAN program will look at the occurrence and distribution of these compounds, especially in the Lower Rio Grande Valley.

Yukon Basin

FY 2002 is the second year of the Yukon River NASQAN study. This year’s activities focus on two work elements: 1) operation of a fixed station network, and 2) synoptic sampling of a portion of the Yukon River (and its tributaries) from Eagle, AK to Stevens Village, AK.

Fixed Station Network: The fixed station network consists of 5 sites - 3 located along the mainstem of the Yukon River and 2 that drain major tributaries to the Yukon.

15356000 – Yukon River at Eagle, AK – 114,000 mi². Represents about one third of the Yukon River Basin. Importance of the site is that it is located above the Yukon Flats, a large depositional area.

15453500 – Yukon River near Stevens Village, AK – 196,300 mi². Located downstream of the Yukon Flats. Comparisons of fluxes at this site with the fluxes from sites upstream of Yukon Flats should indicate amount of deposition of various water quality constituents.

15565447 – Yukon River at Pilot Station, AK – 321,000 mi². Represents the mouth of the basin.

15389000 – Porcupine River near Fort Yukon, AK – 29,500 mi². Drains a permafrost basin.

15515500 – Tanana River at Nenana, AK – 25,600 mi². Drains a glacial basin.

Sampling frequency and constituents Each site is sampled 7 times, once in March (representing low flow conditions) and the remaining six times during the open water season, late May to September. Samples are analyzed for standard NASQAN constituents, suspended trace elements, and suspended sediment. In addition, samples are analyzed for specific NRP studies. These include mercury, radiochemistry, organic carbon, total and dissolved trace metals, carbon dioxide, methane, inorganic carbon, deuterium, and oxygen-18. (NASQAN contributes $50,000 to NRP in partial payment for these laboratory analyses and NRP personnel’s contributions to the Yukon study.)

Synoptic Sampling: Two synoptic sampling trips will be conducted along a portion of the Yukon River from Eagle, AK to Stevens Village, AK. These trips will take place in June and August in order to 1) characterize this section of the Yukon under different flow conditions and 2) determine instantaneous flux of major ions, nutrients, dissolved and suspended trace elements at a large number of points to determine important source areas and patterns of transport and fate. Water quality samples will be collected both along the mainstem of the Yukon River and at major tributaries such as the Porcupine, Chandular, and Sheenjek Rivers. (NASQAN is contributing an additional $75,000; NRP is contributing $50,000, as well as a substantial commitment of NRP personnel and laboratory resources; and AK District has provided planning and support at no additional cost to NASQAN to accomplish this study.)

Columbia Basin

The scope of the NASQAN program in the Columbia River Basin for the period 2001-2005 is much reduced relative to 1996-2000, with sampling at only one index station, the Columbia River at Beaver Army Terminal near Quincy, Oregon (14246900). Nonetheless, sampling at this station continues to be oriented toward the primary NASQAN program objective of characterizing fluxes of water and chemicals out of the basin to receiving waters, i.e. the Columbia River Estuary. One of the important water-quality issues in the Columbia Basin concerns the effect of toxic contaminants on wildlife, especially hydrophobic compounds that are predominantly transported in association with sediment particles. Because of the high degree of flow regulation in the Columbia River, much of the sediment from the upper regions of the basin is deposited in main-stem reservoirs and does not reach the mouth of the river. As a result, local sediment sources assume greater importance. Of particular concern to wildlife in the Estuary is the influence of sediment input from the Willamette River, which is heavily influenced by agriculture and the major metropolitan area of Portland.

The standard approach for flux determination in NASQAN is to develop a regression relationship between constituent concentration with streamflow and seasonal factors, as appropriate. At this site, however, suspended sediment concentration exhibits a generally poor relation with streamflow because of extensive flow regulation upstream, and further weakened by tidal effects. The influence of the Willamette also is a confounding factor, as it contributes a large proportion of the total water and sediment flux during winter storms when flow is relatively low in the main-stem Columbia River. Given the concern about delivery to the Estuary of sediment-associated toxic contaminants, the Columbia Basin NASQAN program is augmenting the routine sampling program with a special turbidity study during 2001-2005. The objectives of the special study are as follows:

· To improve estimates of sediment delivery to the Columbia River Estuary through the use of in-situ turbidity measurements as a surrogate for suspended sediment concentration

· To evaluate the influence of the Willamette River as a source of estimated sediment loads to the main-stem Columbia River

The general approach of the special study will be to explore the relation of turbidity and suspended sediment concentration, in context with other relevant factors. Two continuous nephelometric turbidity sensors have been deployed at the site, co-located with a side-scan Doppler unit monitoring streamflow velocity. Sampling includes a mix of water-quality and field-calibration samples, totaling 15-17 site visits per year.

Data will be used to fine-tune the regression model for estimating loads of suspended sediment, and, if possible, to estimate the percent of silt-sized and smaller particles. Results will analyzed to determine the governing factors for sediment delivery to the Columbia River Estuary, especially the effect of Willamette River inputs. (NASQAN is providing $20,000 for this study.)

Colorado Basin

Two index stations will be operated in the Colorado Basin (Colorado River above Diamond Creek and Colorado River at Northerly International Boundary), the same as last year. Sampling at the compact point (Colorado River at Lees Ferry) is supported through the cooperative program. No special studies or interpretive reports are planned for FY 2002.

Other Special Studies

1. Richard Vogel (Tufts University) is extending his work on estimating the precision of load estimates to include estimating loads at ungaged sites. ($10,000)

2. Art Horowitz (GA District) is preparing a report on the effects of length of record on load estimates. ($15,000)

3. Art Horowitz (GA District) is performing a holding time test for unpreserved large volume samples to determine changes in particulate C, N and P values. ($10,000)

NASQAN Contact Information

For any questions on the NASQAN program, consult our web page (http://water.usgs.gov/nasqan) or contact any of the following individuals:

· National Coordinator: Rick Hooper, Office of Water Quality, Northborough, MA. rphooper@usgs.gov; 508-490-5065

· Mississippi Basin Coordinator: Richard Coupe, MS District, Pearl, MS. rhcoupe@usgs.gov;
601-933-2982

· Rio Grande Basin Coordinator: Becky Lambert, TX District, San Antonio, TX. blambert@usgs.gov; 210-691-9218

· Colorado Basin Coordinator: Bob Hart, AZ District, Tucson, AZ. bhart@usgs.gov; 520-556-7137

· Columbia Basin Coordinator: Valerie Kelly, OR District, Corvallis, OR. vjkelly@usgs.gov;
541-754-4784

· Yukon Basin Coordinator: Tim Brabets, AK District, Anchorage, AK. tbrabets@usgs.gov;
907-786-7105

Stephen K. Sorenson

Acting Chief, Office of Water Quality

This memorandum supersedes OWQ Technical Memorandum 2001.01.

Distribution: A, B, DC, AO, District and Regional Water-Quality Specialists

Attachment 1. FY 2002 NASQAN Stations

Station ID	Name	District	Fixed Samples	Planned Event	Replicates	Sediment Chemistry
Mississippi Basin
03086000	Ohio R @ Sewickley, PA	PA	12	3	3	15
03216600	Ohio R@Greenup Dam	KY	12	3	3	0
03303280	Ohio R@Cannelton	KY	12	3	3	0
03378500	Wabash R@New Harmony	KY	12	3	3	0
*	Cumberland R@ Smithland	KY	6	0	1	6
03609750	Tennessee R @ Paducah	KY	6	0	1	4
03612500	Ohio R nr Gr. Chain	KY	12	3	3	4
05420500	Mississippi R@Clinton	IA	10	3	3	4
06185500	Missouri R nr Culbertson	MT	6	3	2	0
06338490	Missouri R@Garrison Dam	ND	6	0	1	0
06467500	Missouri R@ Yankton	SD	8	0	1	0
06610000	Missouri R@Omaha	IA	12	3	3	0
06934500	Missouri R@Hermann	MO	12	3	3	4
07022000	Mississippi R@Thebes	MO	12	3	3	4
07263620	Ark. R@D.Terry Dam	AR	10	0	2	4
07373420	Mississippi R@St. Francisville	LA	12	3	3	4
07381495	Atchafalaya R @Melville	LA	12	3	3	4
Rio Grande Basin
08374200	Rio Grande blw Presidio	TX	8	0	1	8
08377200	Rio Grande@Foster Ranch	TX	8	0	1	4
08447410	Pecos R. nr. Langtry	TX	8	0	1	0
08450900	Rio G. blw Amistad Res	TX	6	0	1	0
08459200	Rio Grande@Laredo	TX	10	0	2	7
08461300	Rio Grande bl Falcon Dam	TX	6	0	1	0
08470400	Arroyo Colorado nr Harlingen	TX	10	0	2	7
08475000	Rio Grande nr Brownsville	TX	0	5	1	0
Colorado Basin
09404200	Colorado R@Diamond CK	AZ	8	0	1	8
09522000	Colorado R @NIB	AZ	6	0	1	4
Columbia Basin
14246900	Columbia R@Beaver Army	OR	8	0	1	4
Yukon Basin
15356000	Yukon R@ Eagle	AK	6	1	1	7
15389000	Porcupine R nr Ft Yukon	AK	6	1	1	7
15453500	Yukon R@ Stevens Village	AK	6	1	1	7
15515500	Tanana R @ Nenana	AK	5	2	1	7
15565447	Yukon R @ Pilot Station	AK	6	1	1	7

*Station number not yet assigned.

Attachment 2. FY 2002 Funding Allocations by Station and Account Number

Station ID	Account Number	District	Fixed Sampling Cost	Gaging Cost	Total Initial Transfer	Event Sampling Reserve
Eastern Region
03216600	4421-00300	KY	$ 58,593	$ -		$ 13,902
03303280	4421-00300	KY	$ 46,881	$ 11,450		$ 10,974
03378500	4421-00300	KY	$ 51,006	$ -		$ 11,955
03410500	4421-00300	KY	$ 25,420	$ -		$ -
03609750	4421-00300	KY	$ 24,704	$ -		$ -
03612500	4421-00300	KY	$ 47,794	$ 11,450		$ 10,944
TOTAL	4421-00300	KY			$ 277,298
03086000	4442-00350	PA	$ 40,716	$ -	$ 40,716	$ 7,476
Central Region
07263620	4605-00300	AR	$ 29,614	$ 4,725	$ 34,339	$ -
05420500	4619-00307	IA	$ 35,243	$ -	$ 35,243	$ 9,627
06610000	4619-00303	IA	$ 53,262	$ -	$ 53,262	$ 12,600
07373420	4622-00304	LA	$ 61,838	$ -		$ 14,455
07381495	4622-00304	LA	$ 62,164	$ -		$ 14,455
TOTAL	4622-00304	LA			$ 124,002
06934500	4629-00300	MO	$ 51,506	$ 5,450		$ 12,216
07022000	4629-00300	MO	$ 72,458	$ -		$ 17,454
TOTAL	4629-00300				$ 129,414
06185500	4630-00300	MT	$ 19,830	$ -	$ 19,830	$ 8,700
06338490	4638-00300	ND	$ 18,202	$ -	$ 18,202	$ -
06467500	4646-00320	SD	$ 38,384	$ 1,000	$ 39,384	$ -
08377200	4648-00330	TX	$ 28,454	$ -		$ -
08447410	4648-00330	TX	$ 27,414	$ -		$ -
08450900	4648-00330	TX	$ 17,812	$ -		$ -
TOTAL	4648-00330	TX			$ 73,680
08374200	4648-00331	TX	$ 16,670	$ -		$ -
08459200	4648-00331	TX	$ 38,962	$ -		$ -
08461300	4648-00331	TX	$ 21,222	$ -		$ -
08470400	4648-00331	TX	$ 39,372	$ -		$ -
08475000	4648-00331	TX	$ -	$ -		$ 17,160
TOTAL	4648-00331	TX			$ 116,226
Western Region
15356000	4702-00351	AK	$ 65,170	$ -		$ 10,560
15389000	4702-00351	AK	$ 60,830	$ -		$ 8,720
15453500	4702-00351	AK	$ 39,278	$ -		$ 5,128
15515500	4702-00351	AK	$ 21,505	$ -		$ 7,878
15565447	4702-00351	AK	$ 69,160	$ -		$ 11,225
TOTAL	4702-00351	AK			$ 255,943
09404200	4704-00320	AZ	$ 31,364	$ -	$ 31,364	$ -
09522000	4704-00350	AZ	$ 20,766	$ -	$ 20,766	$ -
14246900	4741-00332	OR	$ 22,488	$ -	$ 22,488	$ -

Basin	Number of Stations
Mississippi	17
Rio Grande	8
Colorado	2
Columbia	1
Yukon	5
Total	33

Mississippi Basin

Rio Grande Basin

Colorado Basin

Columbia Basin

Yukon Basin

Eastern Region

TOTAL

Central Region