On Aug. 5, 1974, the Northern Maine Regional Planning Commission (NMRPC) was selected as the lead agency for preparing an EPA-funded Clean Water Act (Section 208) “Aroostook-Prestile Areawide Water Quality Management Plan.” The study area included the towns of Caribou, Washburn, Fort Fairfield, Presque Isle, Westfield, Easton, Mapleton, Mars Hill and Blaine.
In May 1975, the Maine Department of Environmental Protection, in its document “Aroostook River Basin Water Quality Management Plan,” recommended that a “comprehensive and legally enforceable plan of agricultural erosion control” be a “primary consideration” for the northern Maine 208 project.
Norman R. Kalloch, Jr. of Washburn, a soil scientist with the local USDA Soil Conservation Service (SCS), accepted a special assignment with the NMRPC. His outstanding work is reflected in the “Aroostook-Prestile Areawide Water Quality Plan” published in 1978. Following are selected findings concerning agricultural soil erosion from that report.
Using the Universal Soil Loss Equation (USLE), the estimated average cropland soil loss in the nine-town area in 1975 was 7.6 tons per acre per year. SCS scientists pegged the “tolerable” soil loss rate at only 3 tons per acre per year to sustain “long-term soil productivity.”
Of the 103,000 acres of area cropland, only 23 percent had an estimated soil loss below 3 tons per acre per year. “Most of the land in this category has favorable soil and slope conditions. The three to 10 ton soil loss category accounted for 58 percent of the cropland. In this range, the fruits of past soil conservation effort is most apparent, since it is estimated 25 to 35 percent of the land in this category originally had soil losses greater than 10 tons per acre, per year.” Estimated annual soil loss topped 10 tons per acre on 19 percent of the cropland.
The study team assessed soil losses in 44 smaller watersheds within the Aroostook and Prestile basins. Researchers said “the usefulness of this information may lie in possible future programs to alleviate stream pollution and cropland degradation on a small area basis.”
The results revealed numerous opportunities for soil conservation efforts in the lower Aroostook watershed. These included [with 1975 estimated tons of soil loss per acre per year in brackets] Mantle Brook [5.24], Hanson Brook [6.22], Libby Brook [6.51], Merritt Brook [7.31], Monson Mill Brook [7.39], Hockenhull Brook [7.91], Colony Brook [7.97], Pattee Brook [8.14], and Conant Brook [9.94].
Based on a 1977 study of Fort Fairfield’s Libby Brook, the study team declared that soil erosion could deliver about 15 to 17 percent of eroded soil as sediment to area brooks. This contributes to an increase in the total suspended solids (TSS) concentration, turbidity, and unsightly conditions. Suspended solids can harm fish habitat and cause abrasion to fishes’ gills interfering with gill functions and providing an avenue for diseases and parasites.
TSS in area brooks and streams is extremely high during, and immediately after, rainstorms during the growing season. In 1976, a study of sediment concentrations in Conant Brook and McDonald Brook in Fort Fairfield during several storm events showed maximum TSS concentrations ranged from 91 to 3,312 milligrams/liter. These results exceeded the water quality standard of 80 mg/liter agreed upon by the U.S.-Canada Committee on Water Quality in the St. John River Basin.
The authors added “since other possible sources of sediment were found to be negligible or nonexistent during a watershed land use study and field checks, we conclude with great certainty that almost all of the sediment was eroded from agricultural land.”
Excessive cropland soil erosion can cause road maintenance issues. “It is estimated that several thousand cubic yards of sediment are removed each year from ditches in the project area at the expense of the taxpayer.” High erosion rates are also associated with high levels of nutrients and pesticides reaching the watercourses, as these substances are attached to the soil particles or dissolved in runoff.
In the late 1940s, the SCS, in cooperation with the Central Aroostook Soil and Water Conservation District, wrote over 100 (typed and handwritten) plans of conservation operations for farmers each year, complete with land use maps and recommended practices. I still have our family’s plan dated Sept. 9, 1949.
In its report, the NMRPC study team observed “from 1965 to 1970, roughly 115 plans (prior records are not available) were provided to farmers annually. Since that time there has been a continual decline. In 1975, only 12 plans were completed. The reasons for this drastic decline include changing priorities and reduced funding for farm conservation work in the local SCS office.”
Steve Sutter is a retired agricultural and resource economist living on a Presque Isle riverfront property that has been in his family since April 12, 1854. This is the ninth installment of his series on the history of the Aroostook River.
