Friday, August 3rd, 2018
Expert sees promise in curbing algae
Conservation efforts cited
By Nancy Allen
CELINA - Conservation practices aimed at reducing nutrient runoff and resulting toxic algal blooms in Grand Lake are showing promise, said a local water quality official.
Stephen Jacquemin, Wright State University-Lake Campus associate professor of biology and a research coordinator monitoring the lake and other areas, spoke at Thursday's agriculture breakfast meeting in Celina.
Treatment trains containing manmade wetlands on Prairie Creek and Coldwater Creek in the Grand Lake Watershed and a separate agricultural runoff and a retention area in the northern part of the county in the St. Marys River Watershed are reducing nutrient runoff, he said. A water-monitoring station on Chickasaw Creek also shows conservation practices are helping slow nutrient runoff.
Jacquemin said nutrient loading is one of the largest contributing factors in the decline of water quality nationwide. Nutrient runoff comes from many sources, but studies have shown in this area most of it comes from agricultural land.
"It's a global issue, really, but not an impossible issue," he said. "Combining unique and innovative best-management practices like the ones being undertaken here in Mercer County can effect a positive change in water quality, but we have to work together as a community to implement conservation practices to effect positive change."
Jacquemin said tests show phosphorus levels have been reduced by almost 80 percent in treated water at the Prairie Creek and Coldwater Creek sites. The treatment trains pump a portion of the water from both creeks into a series of wetland cells and vegetative areas that pull out phosphorus and nitrogen before the treated water is released into the lake.
"The next step is to expand these treatment trains out into the lake by adding rock check dams and planting vegetation," he said. "These littoral wetlands are catching some of the nutrients that the treatment trains are not catching."
In a separate project, Lake Campus and Ag Solutions officials are monitoring the agricultural runoff and retention area in the northern part of the county. It sits on 135 acres on Halfhill Road between U.S. 127 and Herman Road. Pheasants Forever Inc. received a $325,000 grant from the Great Lakes Restoration Initiative to install the area, which contains test wells, water-control structures, two retention ponds and an underground saturated buffer area that captures nutrients. The land is owned by VanTilburg Farms.
The project is designed to demonstrate the feasibility of capturing and retaining field drainage in two retention ponds and in an underground tile called a saturated buffer to reduce sediment and nutrient runoff, according to Ohio Environmental Protection Agency information. The system reroutes existing field tiles and some surface flow from the field into the retention ponds. The accumulated, nutrient-rich water can then be used in a center-pivot irrigation system to irrigate crops. The underground saturated buffer is designed to catch any overflow from the retention ponds, according to EPA information.
About 10 million gallons of subsurface water have been captured to irrigate crops during five irrigation events during the year-and-a-half the site has been functioning, Jacquemin said.
Preliminary data show the saturated buffer has reduced nitrate concentration in runoff water by about 75 percent and dissolved phosphorus concentration by about 50 percent. The retention ponds reduce nutrient runoff because they hold back field runoff that ordinarily would have eventually flowed into Lake Erie, Jacquemin said.
The project will conclude with a technical report expected some time next year, he said.
Additionally, Jacquemin said tests show that conservation practices on farmland near the Chickasaw Creek water-monitoring station have reduced phosphorus concentration in runoff between 30 to 50 percent over 10 years.
"If you look at any one field or practice in a vacuum, it's just a drop in a bucket," he said. "These practices work if lots of people buy in. It has to be a community effort."
Jacquemin predicted that many more conservation practices aimed at reducing nutrient runoff will be installed in the near future.
"People get it now. We need those producers," he said. "We cannot convert every single acre of farmland into these practices but if the majority of fields has a few of these conservation practices, it makes a difference."
