&EPA United States Environmental Protection Agency Industrial Environmental Research Laboratory Cincinnati OH 45268 Research and Development EPA-600/PS7-80-154 Sept. 1980 Project Summary Demonstration of Debris Basin Effectiveness in Sediment Control R E. Bednar and D J. Fluke This study was conducted to determine the effectiveness of sedimentation ponds, as built during the mid-1970's, in the removal of suspended solids discharged in the runoff from lands disturbed by a typical surface mine in eastern Kentucky. The information in this report should be of interest to any program concerned with suspended solids control in runoff. The selected site included two watersheds in which very little erosion-causing activities had occurred, although strip mining was scheduled for one (Rhoades Branch). Mining activities began with construction of a haul road and nine debris basins in August 1976 and were halted by the UMWA strike in December 1977. During this period, only four of the basins received runoff from disturbed areas. Monitoring showed that efficiency was much lower during storm events than during normal flows, due in part to construction and maintenance practices. The efficiency decreased with time because accumulated sediment was not removed from the ponds. This study was conducted in cooperation with The Kentucky Department of Natural Resources and Environmental Protection, Office of Planning and Research, Frankfort, Kentucky. The final report was submitted in fulfillment of Grant S-801276 by L. Robert Kimball and Associates, Consulting Engineers and Architects, Ebensburg, Pennsylvania, under the partial sponsorship of the Environmental Protection Agency. Work was completed as of December 1979. Introduction Two similar and adjacent watersheds in eastern Kentucky were selected for study in an area where very little erosion-causing activity had occurred Mining was proposed in only one valley (Rhoades Branch) The adjacent control watershed (Dick Branch) was selected to provide background data on water quality where man's activities continued to be limited The Rhoades Branch - Dick Branch Study Area (Figure 1) constitutes a small portion of the eastern Kentucky coal field m the upper reaches of Rock- house Creek, a tributary to the North Fork of the Kentucky River. Although coal was mined in local areas within this watershed, no surface mining had been done in the study area prior to its selection for this demonstration Permission to establish the monitor- ing station in Rhoades Branch was obtained from Beth-Elkhorn Corpora- tion, the surface and-mineral owner Beth-Elkhorn Corporation also pledged the cooperation of its contract miner, Tackett and Manning Corporation, who had earlier signed a cooperation agree- ment with KDNREP Tackett and Manning submitted a ------- Ohio Indiana Illinois West Virginia Tennessee Figure 1. Location of study area. Rhoades Branch Study Area Virginia Scale: 1" - 40 Miles mining plan for Rhoades Branch to KDNREP in June 1975, but indicated that a change in the coal market was necessary before they would begin mining Construction of the monitor housing and weir was completed in March 1976, and electric power was installed in June. Equipment installa- tion was complete by August 31,1 976 In August 1976, Tackett and Manning constructed an access and haul road in Rhoades Branch They also constructed the debris basins as shown on their mining plan These smaller earthen basins were designed in the field by the bulldozer operator, a common practice at that time in this area. Very little mining was done in Rhoades Branch until March 1977, although a head-of- hollow fill had been constructed earlier. Mining continued through the spring and summer of 1977 By the fall of 1977, the main sediment basin on Rhoades Branch upstream of the monitoring station had completely filled, and rather than clean the pond, the company built a dumped rock barrier across the stream 52 meters (170 feet) upstream of the monitor station Mining ceased with the advent of the UMWA strike, December 6, 1977, and was not resumed at the conclusion of the strike on March 27, 1978. The disturbed area was hydroseeded in August 1978, and monitoring continued through March 1979 The project demonstrated the effec- tiveness of debris basins, as built in eastern Kentucky, in reducing the sediment load from strip mining distur- bances to Rhoades Branch It provided information on the change in water quality m Rhoades Branch during and after mining when compared to Dick Branch Conclusions A system of sediment basins, as built in the Rhoades Branch demonstration area, was studied to determine their efficiency over the life of a surface mining operation With time, efficiency of the basins decreased due to lack of maintenance (no clean-out of the ponds, reduced sediment storage, and shorter retention time). On the whole, the pond system delayed off-site sedimentation but did not prevent it The pond system consisted of in- stream ponds, where a bulldozer was used to escavate a portion of the stream channel, using the excavated material to form the downstream embankment. The principal spillway was usually a corregated metal pipe, with the open channel emergency spillway located ai a slightly higher elevation on the opposite side of the embankment Once the ponds were constructed, they were not maintained Clogging of outflow pipes by floating debris and accumulated sediment caused excess use and rapid deterioration of the emergency spillway and embankment and short circuiting of the ponds The unplanned stoppage of mining m Rhoades Branch indicates that future mining within the basin will be done. New ponds, designed according to existing regulations will be required before this mining begins The perma- nent monitoring installation coupled with the high likelihood of future mining makes this area a prime candidate for future sediment basin research The exposure of fresh rock surfaces during mining resulted in rapid chemical weathering Significantly increased concentrations of sulfates, hardness, and conductivity occurred in Rhoades Branch during mining. Although the entire mining area was hydroseeded in August 1978, little change in the rate of weathering was apparent by the end of the study period in March 1979. Sulfates, hardness, and conductivity values have increased by' ------- factors of 4 5, 3.5 and 3, respectively over their premmmg values The poor overall performance of the sediment basins studied may be attributed in part to the following factors 1. The ponds did not have the required storage capacity 2 No maintenance was performed 3 The ponds were not cleaned out when they were filled 4. The outlet pipes became clogged resulting in excessive use and deterioration of the emergency spillway 5 No provision was made for re- moving the pond embankment and contents when no longer operable The monitoring equipment has been in operation since September 1976, with random stoppages from extended power outages and during low or zero flow conditions A general overhaul and equipment reconditioning should be performed before mining begins again. Recommendations It was apparent during field workthat maintenance and cleaning of the ponds were necessary. The importance of maintenance should be addressed and emphasized to inspection officials A schedule for cleaning and disposition of dredge material should be required when the sediment basin plans are submitted. Pond embankments should be removed and properly reclaimed when mining has ceased to prevent gradual deterioration and eventual failure The required storage area is difficult to construct because of terrain constraints in the study area, even with ponds in a series To overcome this problem, several techniques and operating procedures should be encour- aged, including "at-source" controls such as minimizing disturbed areas, providing vegetative buffers, and con- structing sediment traps. Methods to slow the velocity of runoff before it reaches the sediment ponds will decrese the amount and size of sus- pended sediment. Following the field work in this study, the permanent station was turned over to the Department of Civil Engineering, University of Kentucky, so monitoring could be continued, at least intermit- tently. The interruption in mining strongly indicated that future mining will occur, and with changes regarding sediment basin design, occurring due to previous studies and the Office of Surface- Mining Regulations, new basins would be constructed, and should be monitored. R E Bednar and D. J. Fluke are with L. Robert Kimball and Associates, Consulting Engineers and Architects, Ebensburg, PA 15931 John F. Martin is the EPA Project Officer (see below) The complete report, entitled "Demonstration of Debris Basin Effectiveness in Sediment Control," (Order No. PB 80 222730; Cost- $9.00, subject to change) will be available from: National Technical Information Service 5285 Port Royal Road Springfield. VA 22161 Telephone- 703-487-4650 The EPA Project Officer can be contacted at. Industrial Environmental Research Laboratory U.S. Environmental Protection Agency Cincinnati, OH 45268 ------- United States Environmental Protection Agency Center for Environmental Research Information Cincinnati OH 45268 Postage and Fees Paid Environmental Protection Agency EPA 335 Official Business Penalty for Private Use $300 r 00604 L J ------- v-xEPA United States Environmental Protection Agency Industrial Environmental Research Laboratory Cincinnati OH 45268 Research and Development EPA-600/PS7-80-158 Oct 1980 Project Summary Fugitive Dust from Western Surface Coal Mines Frank Cook, Arlo Hendnkson, L Daniel Maxim, and Paul R Saunders In this study, field measurements of •fugitive dust levels were made 250 to 500 meters downwind of mining activities and areas at four surface coal mines in the Northern Great Plains during three different climatic conditions. Ambient dust levels were also monitored. Wide ranges of temperature, wind speed, wind direction, precipitation, soil moisture, and mining activity levels are represented in the field data. Introduction Some fundamental findings were' mine-to-mine differences in average total suspended particulates (TSP) levels were significant, the evidence for seasonal differences is weaker, but consistent with physical theory and prior judgements; and on the average, downwind TSP levels were 35 percent higher than ambient (upwind) levels. Most strippable western coal is located in semi-arid, high plains areas characterized by sparse vegetation, erodable soils, and high winds High ambient dust levels are a result of these factors Disturbance of land by surface coal mining may worsen these dust conditions There exist theoretical models for use in estimating the dispersion patterns for paniculate matter emanating from a point source, such as a power plant stack Recently, attempts have been made to model emission, dispersion, and deposition of fugitive dust from point and non-point sources typical of those from western surface coal mines. To date, however, there have been few attempts to apply statistical techniques to determine empirical relationships between suspended particulate levels in mining areas and explanatory vari- ables, such as mining activity levels and meteorological variables. This study employs such techniques to examine the effects of mine operations on air quality under various meteorological and operational conditions. It is recommended that a large-scale, long-term experimental program be conducted to develop and validate empirical relationships between total suspended particulate levels in western surface coal mining areas and explanatory variables which measure the characteristics of the real dust sources found at such mines Total sus- pended particulate levels should be measured at two or more mines over a period long enough to ensure that a wide range of mining and meteorolog- ical variables are observed. Empirical results should be systematically com- pared to those estimated using published emission factors and dispersion/deposition assumptions In brief, the data collection plan included three visits during different seasons to each of four surface mines Four high volume air samplers were used to measure dust concentrations during these visits Additional data were collected on soil moisture, weather conditions, and activity levels of various mining or mining-related operations. These data are candidate explanatory factors to describe the observed van- ------- ability in dust concentrations Observations for this project were taken at several sites within four mines Three visits were made to each mine to ensure that a wide variety of operating conditions were observed and, additionally, to study the effect of seasons of the year on paniculate values Variables measured during the mine visits included dust concentrations, soil moisture, quantitative data on the pattern and intensity of mining activ- ities, and meteorological variables such as wind speed and direction, tempera- ture, and precipitation. Aerial photographs were taken from which maps were drawn Several factors must be considered in the design of a sampling plan for measuring the atmospheric concentra- tion of particulates Some of these are 1 Emissions sources to be measured 2. Direction of the air sampler from the source 3 Distance of theairsamplerfrom the source 4 Duration of sampling interval. The goal is to place the monitors in such a manner that a profile of the concentration of particulates can be obtained. Sampler locations and sampling intervals are such that suffi- cient amounts of particulates will be collected to give reliable estimates of the air concentration at the receptor point We first considered sampling intervals Dust concentrations were measured with General Metal Works GMWL 2000 high volume air samplers These draw in paniculate matter and pass them through a graded series of paper filters At the end of each observation period, the filters were removed and weighed, and the accumulated dust was con- verted to a concentration in units of micrograms per cubic meter Soil moisture as percent of total weight was recorded at locations designed to reflect diverse soil condi- tions haul roads, the pit and bench, off- mine roads, topsoil or spoil piles, areas of contouring or reclamation, and the surrounding landscape Mining activities were recorded during shifts when dust sampling was active Twelve potential dust-producing activities were observed dragline oper- ation, coal haulage, vehicular traffic on mine roads, vehicular traffic on nearby public roads (usually unpaved), water 2 trucks, scraping, grading, coal loading, coal unloading, blasting, and drilling of overburden and coal The report summarizes the results of various statistical analyses of the data collected as part of this study It judges differences in particulate values measured at various locations, mines, and seasons that can be held to be statistically significant Estimates of mam and interaction effects and complete components of variance analysis are furnished in the report The report presents the findings of differ- ences among samplers such as differences arising between the ambient sampler and those downwind of the mining operation Shown also is the relationship between particulates and activity variables at the mining operations visited Reported,in particular.are the results of preliminary statistical analysis of the data and analysis of variance (ANOVA) on total particulates The results of the analysis of variance support the contention that there were significant differences in readings among samplei locations Also discussed are some of the results of regression analysis tc determine the relationship betweer observed TSP and activity levels foi various mining operations The independent variables consistec of observations on some twelve activ- ities at the mine operation, including dragline operation, coal haulage, drilling, blasting, loading, scraping, grading, etc Additionally, wind speed and precipitation were employed in view of their observed or postulated relationships in previous analyses The first observation of interest m examin- ing the relationship between mine activity and resulting TSP values is the pattern of simple correlation coeffici- ents Two points are worthy of note the exception of variable Q3 (on-mme vehicles) TSP is positively correlated with each of the activity variables and the correlation coefficients are not great Frank. Cook, Arlo Hendnkson, L. Daniel Maxim, and Paul R. Saunders are with Mathematica, Inc., Princeton, NJ 08540 Edward R. Bates is the EPA Project Officer fsee below) The complete report, entitled "Fugitive Dust from Western Surface Coal Mines," (Order No. PB 80 221955: Cost. $15.00, subject to change) will be available from: National Technical Information Service 5285 Port Royal Road Springfield, VA 22161 Telephone: 703-487-4650 The EPA Project Office can be contacted at- Industrial Environmental Research Laboratory U S Environmental Protection Agency Cincinnati, OH 45268 ------- 9BU-/5/-064'0186 Region No. 5-11 United States Environmental Protection Agency Center for Environmental Research Information Cincinnati OH 45268 Postage and Fees Paid Environmental Protection Agency EPA 335 Official Business Penalty for Private Use $300 r L ------- |