# Presentation: 271258

## The NASQAN Program in the Mississippi River Basin

- R.H. Coupe

## NASQAN IINational Stream Quality Accounting Network

## What Was NASQAN I?

- Began in the early 70’s and continued through the mid 90’s
- Goal : to provide nationally comparable information on water quality
- At its peak extent, it included sampling at over 500 stations and was funded at $5 million annually

## Was the Program Successful?

- 	**Yes**, the data has been used in a variety of ways:
- To assess trends in water quality over time
- Used extensively by States in their 305(b) assessments
- To determine the flux of nutrients into the Gulf of Mexico and to determine sources areas for these nutrients within the Mississippi River Basin

## What Happened to NASQAN I?

- Program objectives could not be achieved with available funding
- Inadequate QA/QC program
- Constituents measured did not include important chemicals, such as pesticides and trace elements
- Relation between NAWQA and NASQAN unclear

## NAWQANational Water Quality Assessment

- Begun in the early 90’s
- Seeks to identify, explain, and determine status and trends in WQ conditions
- Includes on a rotational basis >40 basins with a basin size of 10,000 to 100,000 square miles
- Many original NASQAN stations were contained within NAWQA study units

## Big Rivers

- Mississippi River (1.2 million square miles)
- The Great Lakes/St. Lawrence (396,000)
- Rio Grande (336,000)
- Yukon (328,000)
- Columbia (258,000)
- Colorado (250,000)
- Next largest river 20% less than Colorado

## NASQAN II Objectives

- Provide an ongoing characterization of concentrations and flux of chemicals and sediment in the Nation’s largest rivers
- Determine source areas for these materials
- Assess the effect of human influences on the observed concentrations and flux

## NASQAN Sample Collection

- Sampling frequency varies among stations, normally 6 to 15 samples annually, with a possibility of more during extreme high flows.
- The number of samples depends on the expected variability of water quality at the site. Since this is a flux based program, more samples are allocated during expected high flows.

## Slide 10

## Mississippi River at St. Louis during the 1993 flood.

- Mississippi River at St. Louis during the 1993 flood.

## NASQAN Samples Are:

- Collected with appropriate equipment using standard and documented procedures
- Depth and width integrated and velocity weighted
- EDI or EWI with 3 to 10 verticals
- Isokinetic samplers are used

## Collecting Samples

## Slide 14

## Slide 15

## Sampler calibration

## Physical and Chemical Measurements Include:

- Field parameters, T, SC, turb., DO, pH, alk.
- Discharge
- Suspended sediment and percent <63 um
- Nutrients
- Major ions
- Trace elements – dissolved and SS
- Pesticides – water soluble

## PROCESSING : chamber used to prevent contamination. 

- PROCESSING : chamber used to prevent contamination.
- Here filtering for trace elements with 0.45 um capsule filter and masterflex pump with Teflon tubing.

## Processing occurs on site, unless a field office is close

## Processing for pesticides using a 0.7 um nominal pore size baked glass fiber filter

## All WRD Field Offices have something comparable to Montana’s mobile laboratory for processing in the field

## Extensive QA Program

- Well defined protocols for sampling, sample processing, chemical analysis and data review
- QC program includes:
- All field personnel participate in the NFQA program
- Evaluation of quality control samples, including field blanks, replicates, and field-matrix spikes
- On site inspections

## Fluxes are computed using the rating curve method

- The rating curve equation *f*(*Q*i) has the form:
- ln(L) = ao + a1ln(*Q*) + a2ln(*Q*)2 + a3sin(t) + a4cos(t) + a5t

## NASQAN Products

- Data
- Online as soon as it is received by District
- Interpretative
- Presentations at meetings and conferences
- Special volume of Hydrological Processes
- Yield maps just published online for 1995-98

## 2001 Mississippi State Soccer Champions, Division III, U14 Girls