Bimonthly Water Quality Sampling

The Bimonthly Sampling Program is ORSANCO’s long-term water quality monitoring program for the Ohio River. The monitoring program began in 1975 and has a continuous record through the present day at 29 locations: 15 stations on the main stem of the Ohio River and 14 points near the mouth of major tributaries. The program’s six-sample annual design provides long-term trend monitoring of the Ohio River while maintaining an ability to evaluate attainment of water quality criteria.

Bimonthly Sampling Program water quality parameters include:

  • Ammonia as Nitrogen
  • Bromide
  • Chloride
  • Hardness (as CaCO3)
  • Nitrate Nitrite
  • pH
  • Specific Conductivity
  • Sulfate
  • Temperature
  • Total Dissolved Solids
  • Total Kjeldahl Nitrogen
  • Total Organic Carbon
  • Total Phenolics
  • Total Phosphorus
  • Total Suspended Solids

Samples are collected every second month, in January, March, May, July, September, and November. Most samples are collected from United States Army Corps of Engineers Locks and Dams, the remainder are collected from bridge or bank locations. The Bimonthly Sampling Program Monitoring Stations are (Ohio River confluence mile points are given for tributary stations with tributary mile points enclosed in parenthesis):

  • Allegheny River at Pittsburgh, Ohio R. Mile 0.0, (-7.4)
  • Monongahela River at South Pittsburgh, Ohio R. Mile 0.0, (-4.5)
  • Beaver River at Beaver Falls, Ohio R. Mile 25.4, (-5.3)
  • Ohio River at New Cumberland, Ohio R. Mile 54.4
  • Ohio River at Pike Island, Ohio R. Mile 84.2
  • Ohio River at Hannibal, Ohio R. Mile 126.4
  • Ohio River at Willow Island, Ohio R. Mile 161.8
  • Muskingum River at Marietta, Ohio R. Mile 172.2, (-0.8)
  • Ohio River at Belleville, Ohio R. Mile 203.9
  • Kanawha River at Winfield, Ohio R. Mile 265.7, (-31.1)
  • Ohio River at R.C. Byrd, Ohio R. Mile 279.2
  • Big Sandy River at Louisa, Ohio R. Mile 317.1, (-20.3)
  • Ohio River at Greenup, Ohio R. Mile 341
  • Scioto River at Lucasville, Ohio R. Mile 356.5, (-15)
  • Ohio River at Meldahl, Ohio R. Mile 436.2
  • Little Miami River at Newtown, Ohio R. Mile 464.1, (-7.5)
  • Licking River at Covington, Ohio R. Mile 470.2, (-4.5)
  • Great Miami River at Elizabethtown, Ohio R. Mile 491.1, (-5.2)
  • Ohio River at Markland, Ohio R. Mile 531.5
  • Ohio River at McAlpine, Ohio R. Mile 606.8
  • Ohio River at Cannelton, Ohio R. Mile 720.7
  • Green River at Sebree, Ohio R. Mile 784.2, (-41.3)
  • Ohio River at Newburgh, Ohio R. Mile 776
  • Ohio River at J.T. Myers, Ohio R. Mile 846
  • Wabash River at Route 62 Bridge, Ohio R. Mile 848, (-32.5)
  • Ohio River at Smithland, Ohio R. Mile 918.5
  • Cumberland River at Pinkneyville, Ohio R. Mile 920.4, (-16)
  • Tennessee River at Paducah, Ohio R. Mile 934.5, (-6)
  • Ohio River at L&D 52, Ohio R. Mile 938.9

Grab Sample Methods

River water samples are collected as near to the centerline of the river as possible from lockchamber guidewalls, bridges, and in some cases from raw water intake lines. To sample from outside structures an acid, distilled, and native water-rinsed bailer, stainless steel bucket, or Kemmerer sampler is used with sufficient nylon rope attached to reach the river surface. Samples are transferred from the collection device to a likewise triple-rinsed ten-liter plastic carboy. The sample water is distributed from the carboy to sample bottles, each containing preservative if required by the analytical methods to be employed.

For more information on the Bimonthly Water Quality Sampling Program, please contact Sam Dinkins.


Ohio River Long Term Water Quality Trends Report Download
Bimonthly Monitoring Locations Download