Phosphorus is an important nutrient for healthy plant growth. However, excess phosphorus in surface water can result in algae growth, causing eutrophication and overall poor water quality. Sources of excess phosphorus to aquatic ecosystems include both point and non-point source runoff from agriculture, horticulture, urban and suburban landscapes.

A relatively new process, called a Phosphorus Removal Structure, has been devised by researchers to provide a landscape “filter” that can remove dissolved phosphorus in runoff before it reaches streams and lakes. Many industrial by-products that are typically land-filled, including materials produced during drinking water treatment, power generation, and steel production have a beneficial re-use in improving surface water quality by attracting and binding or absorbing phosphorus from passing water.

Phosphorus Removal Structures

Phosphorus Removal Structures are placed in hydrologically active areas such as drainage ditches in order to serve as large landscape filters. These structures are filled with Phosphorus Sorbing Materials (PSMs) that directly bind and remove Phosphorus from water passing through them. This water filtering process reduces the Phosphorus concentration of water exiting small watersheds such as crop or pasture production fields, suburban neigborhoods, or golf facilities, prior to the water draining into larger bodies of water in a manner that “traps” Phosphorus. The ability of a Phosphorus Removal Structure to “trap” this element is what allows Phosphorus to ultimately be removed from the watershed.


Phosphorus Removal Construction

Construction phase of Phosphorus Removal Structure in Illinois River Watershed


Phosphorus Removal

Structure completed as part of USDA NRCS Conservation Innovation Grant to IRWP and OSU

Currently, there is no widely utilized land and water Best Management Practice (BMP) that can permanently reduce dissolved Phosphorus loading from high Phosphorus soils within a reasonable amount of time.


The IRWP and Oklahoma State University received a $132,000 USDA Natural Resources Conservation Service Conservation Innovation Grant (CIG) to install and demonstrate a Phosphorus removal structure with the following goals and objectives:

GOAL 1: To remove 50% of the dissolved Phosphorus load.

  1. Construct a phosphorus removal structure on a farm located in the Illinois River watershed which is strategically placed to intercept runoff occurring immediately around a poultry production house.
  2. Monitor the effectiveness of the structure by sampling inflow and treated water through the use of automatic samplers and flow meters, thereby determining the phosphorus load reduction.

GOAL 2: To demonstrate the ability of Phosphorus Removal Structures to be productive NRCS EQIP program Best Management Practice.

  1. Present the structure to 1,000 agricultural producers, policy makers, and stakeholders in the area via field tours, presentations and the web.
  2. Estimate the cost of implementation of this new BMP in watersheds of Northwest Arkansas and Northeastern Oklahoma and the potential phosphorus load reductions.


This conservation project is innovative primarily because there is no current BMP that can immediately reduce dissolved Phosphorus (the most ecologically potent form of P) losses from high Phosphorus soils with any permanence. Even if we cease all Phosphorus applications to high Phosphorus soils, it will require many years before the soil test concentrations decrease to levels that will not produce elevated Phosphorus concentrations in runoff. In the meantime, much dissolved Phosphorus will be lost.

This technology will provide producers with the only tool they would have to reduce dissolved Phosphorus losses from high Phosphorus soils for many watersheds, including the Illinois River Basin. There is great potential for commercialization of this technology by the private market and not only has this technology not been widely demonstrated, but there has been no major effort in determining the cost of implementing this technology to a large area.

The reason we are able to conduct a cost-benefit analysis is because we have developed a model that can aid in designing structures and predict how much Phosphorus will be removed.  We plan to reach over 1,000 agricultural producers, water quality advocates, and representatives from state and federal agencies, which will help to lead to the acceptance of this new BMP that is so needed in this watershed and in similar scenarios throughout the country.



We are conducting the first field day for our Phosphorus Removal Structure Project on Friday, May 23, from 10:00 am to 1:00 pm.  Interested stakeholders are invited to attend and to learn more about this project.   The field day will start at Arvest Bank in Westville, Oklahoma and following a presentation and lunch, a tour of the nearby research site will be conducted. Drs. Chad Penn and Josh Payne, of OSU will present the technology and results to date of this innovative conservation project in the Illinois River Watershed.

About our speakers:

Chad Penn: Associate Professor of Soil and Environmental Chemistry. Dr. Penn pioneered the development of the first P removal structures (Penn et al., 2007) and also the first (and only) model for designing them and predicting performance. Dr. Penn will design the structure and manage its construction, monitoring, and data management. Dr. Penn will also oversee the experiments involving the spent PSM materials. He will manage a graduate student in achieving these tasks.

Josh Payne: Animal Waste Extension Specialist. Dr. Payne provides expertise to agricultural producers in regard to animal waste management, especially to poultry producers in the Illinois River Watershed and throughout Oklahoma. Dr. Payne provides mandatory training and education to all poultry producers and litter applicators in the state of Oklahoma. Dr. Payne will manage all field presentations of the P removal structure and also dissemination via his poultry waste training and symposia. Dr. Payne is also heavily involved with the interaction between water advocacy groups and poultry producers in Eastern OK, therefore his dissemination efforts will reach them as well.


Additional information about the field day:

Target audience includes agricultural producers and stream side landowners, state and federal agencies, educators (formal and informal), non-profit organizations, civic groups, and professionals in the field.  Registration is required and there is a maximum enrollment of 30 registrants.

Cost:  Free, with required registration at or by calling 479-215-6623 to RWVP

Date and time:

Friday, May 23, 2014

Check in 10:00 am

Program 10:15 am to 1:00 pm


Arvest Bank

901 N. Hwy 59

Westville, OK


Related Posts:

Water Proof:  Water Quality Studies in the Illinois River Watershed

Water Proof:  Tackling Wicked Problems

Water Proof:  Watershed Management for the Future