The Effects of LandUse on The Ozark Plateau Aquifer System
Figure 1: Area Extent of Ozark Plateau Aquifer System. Photograph taken from USGS with permission
The Effects of Landuse on The Ozark Plateaus Aquifer System

Submitted by:
Les Thomas

Contents
Introduction and Scope Hydrologic and Geologic Features.
Water Resources Land use and Contamination
Future References

Introduction and Scope

This is an investigation of the Ozark Plateau Aquifer system for the partial fulfillment of GEO 571 Hydrogeology at Emporia State University, Emporia, KS. This aquifer system is a large system comprised of several smaller aquifers that cover a large geographic area in Kansas, Missouri, Oklahoma and Arkansas. This system includes the Springfield Plateau, Ozark, and the St. Francois Aquifers. Historically, this aquifer system has been the most important water source for southeast Kansas, southwest Missouri, northeastern Oklahomas, and northern Arkansas (Macfarlane, et.al.,2005) The purpose of this report is to investigate the future of the aquifer system with regard to the regional water demand and current and past land use practices. The age of rocks that comprise this system range from Cambrian to Mississippian. The rocks consists of dolomite, sandstone, shale, and chert which tend to dip southward. The aquifer system reaches into northern Arkansas, southern Missouri and small portions of southeastern Kansas and eastern Oklahoma as illustrated in figure 1. This study unit encompasses most of the aquifer which includes all four states. It has an area of 48,000 square miles (Renken, 1998). In an excess of 2.3 million people live in this study area. Population increased in this area 28 percent between 1970 and 1990 (Petersen, et.al,2005)

There are major water quality concerns in the study area that include elevated concentrations of nutrients, elevated concentrations of bacteria, trace elements, dissolved solids, and radionuclides in ground water from agricultural and industrial activity (Petersen, et.al.,2005). Abandoned zinc and lead mines in the tri-state area of Kansas, Oklahoma, and Missouri and active coal mines in this area are also causing contaminates to leach into surface water run-off. This contaminated run-off is entering the shallow ground water aquifers (Peterson et.al, 2005) (Miller and Appeal). Increased demand for fresh water is pulling contaminated water from the shallow aquifers into the fresh water aquifers. Also as groundwater supplied to area municipalities and rural water districts increase deep water is being pulled to the upper regions of the aquifers . At the bottom of the Ozark aquifer is a brine layer (salt water) that is moving west to east across Kansas. Concerns are that significant groundwater pumping in areas could potentially cause upwelling of brines within the aquifer that would decrease the water quality in these areas (Macfarlane, 2005).

The study area has a temperate climate with average annual precipitation ranging from 38 to 48 inches per year; an average annual temperature of 56-60 degrees F, the rates of evapotranspitation ranges from 30 to 35 inches per year, and the average annual runoff and infiltration is about 8 inches per year (Petersen, et. al., 2005). The aquifer systems primary recharge source is from leaky shallow aquifers, infiltration in unconfined areas, and precipitation on outcroppings. Many of the shallow aquifers that overlay the Ozark Plateau Aquifer System are fast becoming contaiminated with surface waters that have washed over mining waste and feedlots. There are currently two EPA Superfund sites within the Ozark Plateau System that is directly related to lead and zinc mining practices. One is located in Cherokee County, Kansas and the other is located at Picher, Okalahoma. Figure 2 shows a the result of mining contamination of a portion of Tar Cheek, located at Picher, OK(EPA, 2005).

Figure 2: A polluted portion of Tar Creek due to lead and zinc mining at Picher, OK. Photograph taken from USGS with permission

Figure 3: Relationship between the Springfield Aquifer and the Ozark Aquifer in southeast Kansas and Southwest Missouri. Image obtained from KSDA with permission

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Hydrologic and Geologic Features

The largest fresh water aquifer of the Ozark Plateaus System is the Ozark Aquifer. Figure 4 shows the extent of the Ozark Aquifer with respect to the rest of the system. It consists mostly of limestone and dolomite ranging in age from the Devonian to Cambrian. Some areas of the aquifer are comprised of sandstone, chert, and shale. The aquifer covers approximately 37000 square miles in southern Missouri and north central Arkansas. The Upper Cambrian Potosi Dolomite, the Lower Ordovician Gasconade Dolomite,the Gunter and Roubidoux Sandstone Formations of the aquifer are the main water producing formations of the Ozark Aquifer (Renken, 2005).

The Roubidoux and the Gunter Sandstones yeild large amounts of water. The Gasconade Dolomite formation is comprised of a cherty dolomite that is about 100 feet thick with poor hydraulic conductivity and in contrast yeilds much less water. The Roubidoux formation extends eastward across northern Arkansas and contains dolomite, quartz sandstone, and chert. The Gunter Sandstone is the main water yeilding formation in which production rates are about 150 to 300 gallons per minute. The Gunter contains mostly quartz sandstone. The Ozark confining unit consists of mainly shale with some limestone with little permeability. Water can recharge into these aquifers by either infiltrating through the soil, or by direct runoff into streams. There is a very large cavern system that runs underneath the surface due to an extensive Karst topography. The fractures and partings in the bedding planes due to this Karst topography provides an avenue for surface water to recharge the aquifer. The lithology of the three aquifers, confining units, and the hydraulic properties are consistent throughout a large area (Renken, 1998).

The Springfield Plateau aquifer is the shallowest aquifer of the Ozark Plateau System and overlies the Ozark aquifer. It is comprised of mostly Mississippian limestone. The Burlington and Keokuk Limestone are the most productive of the Springfield Plateau aquifer. These formations also yield water north of the Missouri River, but this water is considered to be part of a separate aquifer, the Mississippian aquifer. The Springfield Plateau aquifer has an average thickness of 200 feet (Miller and Appeal). Most of the recharge water moves through solution caves and fractures. The water is slightly acidic which is common to Karst topography normally found in areas underlain by limestone. Recharge is mostly from precipitation that percolates downward to the water table, most of which moves laterally to discharge as base flow to nearby streams. A small of amount of recharge is from the upward leakage of water from the lower elevation of the Ozark aquifer in places where the hydraulic head of the Ozark aquifer is higher then that of the Springfield Plateau aquifer. In some places in the outcrop area of the Springfield Plateau aquifer, the water levels are higher than that of the Ozark aquifer and water leaks downward to recharge the Ozark aquifer. Upward and downward leakage occurs throughout the Ozark confining unit that separates the Springfield Plateau and Ozark aquifers. The primary use of the Springfield Plateau water is used for domestic and stock watering. Wells produce less than 20 gallons per minute. Figure 3 shows the relationship between the Springfield and Ozark aquifers in southeast Kansas and southwest Missouri.

The St Francois aquifer is the lowest aquifer of the Ozark Plateau System of aquifers. The aquifer is exposed to the surface only in the St Francois Mountains located in Missouri on the eastern side of the aquifer system. The aquifer varies in depth from in northern Arkansas from 1500 feet to 4000 feet. The St Francois aquifer is not a used as a source of water for regions of northern Arkansas because the depth to the productive zone would make completing wells too expensive. The top slopes eastward away from the St Francois Mountains and becomes buried beneath the Ozark aquifer. The St Francois aquifer is used as a water source just for the region near the St Francois Mountains.

The St Francois aquifer is composed of the Bonneterre Dolomite, Reagan and Lamotte Sandstone from the Cambrian age. Most of the water is produced from the Lamotte Sandstone with rates as high as 500 gallons per minute. The Bonneterre Dolomite yields between 10 to 50 gallons per minute. Production data from the Reagan Sandstone is not well documented. The thickness of the St Francois aquifer averages about 400 feet in south-central Missouri west of the St Francois Mountains thickening to greater than 700 feet in several locations to the north, east and southeast of the mountains. The aquifer thins out at its western and southern edge. The aquifer thickness is irregular due its formation being deposited on a rugged eroded surface of Precambrian rocks of the bottom of confining unit. Production from the St Francois aquifer is from outcrops or shallow depths. Due to this area of production, little is known about the water levels in the aquifer, but regional flow within the aquifer appears to be controlled by topography. Water moves along short flow paths and discharges as base flow to local streams. Some water moves into confined parts of the aquifer and discharges to shallower aquifers by upward leakage (Gillip et.al.).

Image taken from Figure 4 illustrates the relationship of the different Aquifers in the Ozark Plateau System. Figure was obtained with permission from the USGS

Figure 5 illustrates an estavelle, a sinkhole that is reversible; water may flow into the sinkhole at times and out of it at other times.Figure was obtained with permission from the USGS

The formations in the area containing the Ozark Plateaus Aquifer System are generally carbonates. Limestones and dolomites are common. Rainfall averages range from 30 to 60 inches over the entire aquifer system. As a result of this area being well watered and having carbonate formation, Karst topography is common. Northern Arkansas and southern Missouri are notable for the karstic features. Karstic features include sinkholes, conduit springs, disappearing springs, and large, extensive systems of caverns. Sinkholes are common occurrances in Arkansas and southern Missouri. Sinkholes are defined as oval shaped depressions that are formed from the dissolution of carbonate bedrock. Some sinkholes, such as the one shown in figure 5, are reversible; that is, water may flow into the sinkhole at times and out of it at other times. Such a sinkhole is called an estavelle. The Ozark aquifer has generally less sinkholes than the Springfield aquifer. These sinkholes are important because this is where recharge enters the aquifer directly. Springs are also a major aspect of the aquifer system. This is where discharge from the aquifer flow to the surface and out onto the surface of the land. Typically these springs are located on the sides of steep valleys or exposed outcroppings. Discharge is varied, but can be in excess of 100 cubic feet per second.

Caves are also a common feature in this locale as well. There are more than 1,000 known caves in northern Arkansas and southern Missouri. Some of these caves have been said to reach about 1,000 feet below the land surface. Recharge through cave networks and sinkholes can reach extreme volumes (Renken, 1998). Figure 6 illustrates the nature of solution processes associated with karstic topography.

The Karst areas of the Ozark Plateaus System of Aquifers receive water that has infiltrated through these sinkholes and cave networks. As a result, the water that recharges the aquifers become contaminated from mining debris, septic systems, agriculture chemicals, and feedlots (Cooper et.al.). Missouri is more susceptible to contamination through karst features because there are more mature karst features in the state than there are in Arkansas (Davis and Witt, 2005) Figure 7 illustrates the solution features associated with Karstic topology (Cooper et.al.).

Figure 6: Solution Features Associated with Karstic Topology. Figure used with permission from Geoindicators

Figure 7: Picture of a Contaminated Pond near Tar Creek. Image obtained with permission from EPA

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Water Resources

The main source of water that enters the Ozark aquifer is through precipitation that falls on and near the outcrop sites. Some of the water is infiltrated from the overlying aquifers. The Chattanooga Shale is the confining unit over the Ozark aquifer and is thin or absent in some areas. Where the shale is fractured over the Ozark aquifer it allows the Springfield Plateau aquifer to leak downward, recharging the Ozark aquifer. Studies have been done to map the ground-water movement, and most indicate that the movement is dictated by the topographic relief. Surface water flows regionally to rivers and streams. The regional water movement is northwestward, eastward, and southward from the St. Francois mountains. Ground-water flow is southeastward in the eastern part of the aquifer. Even though the aquifer formations extend beyond the Boston Mountains there is thought to be a ground-water divide underneath the Boston Mountains. The Springfield aquifer's main use is a source of domestic water. The Ozark is used for domestic and public water, as well The Ozark aquifer reaches into Missouri and parts of Kansas and Oklahoma. A cone of depression was found in Springfield, Missouri many years ago due to the population amount in the area. People have now been moving into the rural areas which causes the cone to subside (Renken, 1998). Total fresh water withdrawals for the Ozark Plateaus aquifer system was estimated to be approximately 330 million gallons per day, during the 1990s. Eight million gallons were withdrawn in Kansas; about 139 million gallons per day was withdrawn for agricultural purposes, which was the principle use. About 88 million gallons per day was used for public supply and about 53 million gallons per day was used in industrial, mining, and thermoelectric power useds. Domestic and commercial withdrawals were about 50 million per day. Well tests for the Springfield and Ozark aquifers in the tri-state region of Missouri, Kansas, and Oklahoma were conducted. Test indicated a transmissivity ranging from 5,100 square feet per day from the Ozark aquifer in Oklahoma to 540 square feet per day in the Ozark in Missouri. Transmissivity as high as 33,800 square feet per day from the Springfield Plateau and Ozark aquifers in Kansas. Storitivity in these areas ranged from 0.00008 to .0002 respectively (Macfarlane and Hathaway,1987).

The Ozark aquifer extends into southern and central Missouri where it is used as mostly agriculture, domestic and public uses. The area is primarily forest and agriculture that includes pastures and cropland. Diciduous forest and evergreens make up the forest regions. Environmentalists are worried about the increase demand on the aquifer systems drawing shallow water into the main aquifer system and the the number of contaminants entering the water through karst features. It has been shown that microbial activity in ground water can be affected by fractures, faults and karst due to losing streams, sinkholes and many other solution channels. In a recent study, 95 percent of of the public water is dependent upon the ground water. The ground water here is extremely susceptible to contamination and other harmful materials (Davis and Witt, 2005). Water use has been regulated in southeast Kansas as illustrated in Figure 8

Image taken from Figure 8: Regulated Water Use Map of Ozark Aquifer in kansas. Figure used with permission From KSDA

Figure 9: How Contaminates Enter Groundwater. Figure used with permission from Environmental Canada

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Land Use and Contamination

The surface activities over laying the Ozark Plateau Aquifer System include mining, poultry and beef production, farming and assorted industries. Mining in some sites are common in the Tri-State area of southeastern Kansas, southwest Missouri, and northeastern Oklahoma. Coal, lead, zinc, and limestone are the products of these area mines. Lead and zinc mines in the Tri-state areas have been closed down since the mid to late 1970s. Some coal mines in Oklahoma, Missouri, and Arkansas have been closed down, as well. Currently there is still strip mining of coal and limestone is some parts of this area. At one time in the area, coal mining was so extensive, that the second largest mining equipment used was located in southeast Kansas. A large drag link named Big Brutus with the capacity of 90 cubic yds was located in Cherokee County, Kansas. Big Brutus now sits idle and is the featured display at the Big Brutus, Inc. mining exhibit located in West Minerial, Kansas. Figure 10 illustrates the giant drag link, Big Brutus.

Arkansas is second largest poultry producer and eighth largest beef producer in the country. Kansas, Missouri,and Oklahoma are also large producers of beef. Feedlots and poultry yards are common in the area over laying the aquifer system.(USDA) Limestone quarries are prevalent in southeast Kansas. Small manufacturing plants and industries that include electronic component manufacturing, cement plants, waste disposal, battery plants, paint manufacturing, fertilizer,wood preservative, pesticide, and fuel and solvent manufacturing are located in this region. Increases in local population have resulted in a removal of vegetation and regrading land surfaces for new building sites.

These surface activities are common and wide spread in almost the entire world. So why are these practices a cause for concern? The geology of the area is largely sedimentary rocks consisting of limestone and dolomite. These sedimentary rocks are carbonates and are subject to dissolution in the presence of acidic water. Karst topography is common in the area. The mining operations of the late eighteen and early nineteen hundreds in the area for coal, zinc, and lead were abandoned when mining was no longer profitable. The abandoned mines flooded when they were abandoned. The smelting plants for the ores were also abandoned. Areas around the mine and smelting sites were left with large amounts of mining wastes and milling wastes. These wastes or chat and tailings, were left in large piles covering square kilometers. Surface water washed over the waste and flooded the abandoned mine shafts. The mine openings and strip pits acted like the solution caves and paths typical of Karst topography. Large volumes of surface water contaminated with mining waste, human and livestock waste, and industrial waste found their way into shallow aquifers.

Mine shafts collapsed due to mine creep, a phenomena similar to sinkhole production in karst topography opened more avenues for contaminated water to enter the ground water systems. Collapsed mine shafts and sink holes in the area were used as city dumps or waste disposals further added to the contamination of ground water.

Increase in population has created an increase in water production. As more individuals are consuming water, more water has to be produced from ground water supplies. Shallow wells in shallow aquifers are plugged to prevent the consumption of contaminated water forcing individuals to seek water from other sources. Municipal water wells are being over produced. As a result, water levels in the aquifers are declining, causing more wells to be placed deeper in the aquifer to be productive. Saline water found at the bottom of the aquifers is being pulled up into the fresh water increasing the chloride contamination, Sulfides from lead and zinc operations are entering the aquifers through ground water recharge areas. Lead and heavy metals are also entering the aquifers from leaky contaminated shallow aquifers. Carbonates and magnesium from the dissolution of the limestone and dolomite are increasing. Ground water is becoming increasingly more acidic from coal operations. Entire communities in Oklahoma have been abandoned due to the increased levels of toxic materials in the surface and ground waters.

The ground-water contains calcium or calcium magnesium bicarbonate. In some locations calcium sulfate or sodium chloride can be found where the aquifers are confined. The pH of the ground-water ranged from 5.2 to 8.3. Nitrate concentrations are also found in the Ozark aquifer and the Springfield Plateau. The Ozark aquifer is used extensively for agriculture. Agriculture operations can cause an increase in the concentrations of nutrients and bacteria in the ground-water. The chemical quality of the water is suitable for human and animal consuption, however, since the late 1990s there has been an increase in dissolved solids from less then 1000 milligrams per liter to around 2000 milligrams in some areas of the aquifer systems. These numbers vary in different locations of the aquifer depending on geology and land use. (Renken, 1998). Most contamination occured in or near agricultural land and industrial areas (Petersen et.al, 2005).

Figure 10: Giant Drag link, Big Brutus, used to mine coal in Southeast Kansas. Figure taken with permission from Big Brutus, Inc Mining Museum, West Mineral,KS

Figure 11: Tar Creek Runs Red From Mining Contaminates. Figure taken with permission from EPA

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Future

The future of the Ozark Plateau Aquifer System depends on continuous conservation practices and remediation programs. The surface water entering ground water through sinkholes, springs, solution pipes is typical of area and in itself is not a concern. But the open mine shafts, mine cave-ins, and strip pits increase the recharge potential of the aquifer system by acting like karstic topography. This situation coupled with the high levels of surface pollutants contaminating the water is a major concern. The shallow aquifers that once provided a viable source of domestic water is now so contaminated that it has no value. Current and past mining, industrial, and farming practices have increase the contaminate load of surface waters. Land development and vegatation removal caused by urban spread has eliminated natural filtration sources and increased erosion resulting in increased mineral and dissolved solids.

Recent population growth in the region of the aquifer system means more demand for water. Over production of the aquifer system has lowered the water table in some regions of the aquifer system. Water is more likely to be drawn from leaky contaiminated shallow aquifers or bottom water that has a high concentration of salts is being pull up into the fresh water regions of the aquifers. Seasonal changes in chemistry has been documented in the larger fresh water Ozark and Springfield Plateau aquifers.(Macfarlane, 2005)

There are currently active EPA Superfund projects in southeast Kansas and northern Okalahoma involving the clean-up of toxic materials from past mining operations. Mining debris is no longer being used as road paving material. Strip mines where limestone, coal, and other shallow minerals are being covered over with clay materials and soil. Native grasses are being planted over reclaimed mine areas. Shallow wells that have become contaminated are being capped. Health problems such as lead poisoning related to mining and smelting practices have decreased. Contaminated soils have been removed and properly disposed of.(EPA,2006)

Farmers are becoming aware of the impact that farm chemicals can have on surface and ground water quality. Farming practices of spreading animal feces on crops for fertilizer is still wide spread in association with feedlots. The United States Department of Agriculture is currently working on a best management practices for waste management for feedlots and poultry operations.(Shi, 2001)

In summary, land use practices including past and present agriculture, mining, industrial and development have increased the amount of pollutants exposed to run-off. Increased demand for water has lowered the water table. Cation and anion content has increased in aquifer waters. karst topography has increased surface water recharge of the aquifers. These conditions have collectively threaten the quality of the Ozark Plateau Aquifer System. Increased awareness of land-use practices and government programs have begun to address these problems and throught the combined efforts of local citizens and the local, state, and federal government, a bright future exists for the aquifer system.

More information about this aquifer systems and its future can be obtained from several agencies such as the US Department of Agriculture, The Bureau of Mines, The US Department of Interior, and the Evironmental Protection Agency.

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References

Cooper, A.H, Farrant, A.R., Palmer, A.H., 2007. Karst Activity. In Geoindicators, an online site maintained by the International Union of Geoscientists. Availabale on line at http://www.lgt.lt/geoin/doc.php?did=cl_karst. (Date accessed: May 12, 2008)

Davis, J. C., and Witt, E. C., 2005. Microbiological Quality of Public Water Supplies in the Ozark Plateaus Aquifer System, Missouri. U.S. Geological Survey Fact Sheet #fs-028-98-davis Available on line at http://mo.water.usgs.gov/fact_sheets/wtrqual/fs-028-98-davis/. (Date accessed: May 13, 2008)

Gillip, J.A., Czarnecki, J.b., and Mugel, D.N.,2008, Potentiometric surfaces in the Sringfield Plateau and Ozark aquifers of northwestern Arkansas, southeastern Kansas, southwestern Missouri, and northeastern Oklahoma, 2006: U.S. Gelogical Survey Scientific Investigations Report 2007-5253, 25p

Imes, J.L., and Emmet, L.F., 1994, Geohydrology of the Szark Plateaus aquifer system in parts of Missouri, Arkansas, Oklahoma, and Kansas: U.S. Geological Survey Professional Paper 1414-D, 127 P.

Macfarlane, P.A., Healey, J.M., and Wilson, B.W., 2005 THE SOUTHEAST KANSAS OZARK AQUIFER WATER SUPPLY PROGRAM PHASE 1 PROJECT RESULTS, Kansas Geological Survey Open File Report 2005-15 15p. Also available at:http://www.kgs.ku.edu/Hydro/Publications/2005/OFR05_15/aquifer.pdf. (Date accessed: May 13,2008)

Macfarlane, P.A., and Hathaway, L.R., 1987, The hydrogelogy and chemical quality of ground waters in the lower Paleozoic aquifers in the Tri-state Region of Kansa, Missouri, and Oklahoma: Kansas Geological Survey Open-file Report81-16, 48 p

Miller, James A., and Appeal, Cynthia L., 1997, GROUND WATER ATLAS of the UNITED STATES, Kansas, Missouri, and Nebraska, HA 730-D. Available on line at Http://www.capp.water.usgs.gov/gwa/ch_d/-text5.html (Date accessed: May 13,2008)

Parker, Suzi, 2006, Finger-Lickin'Bad, Grist News Watch. Available on line at http://www.grist.org/egibin/printthis.pl/maindish/2006/02/21/parker/index.html (Date accessed May 13,2008)

Petersen, J.C., Adamski, J.C., Bell, R.W., Davis, J.V., Femmer, S.R.,Freiwald, D.A., and Joseph, R.L., 2005. Water Quality in the Ozark Plateaus. National Water Quality Assessment Program. Available on line at http://ar.water.usgs.gov/nawqa/ozark/setting.html

Shi,Y., Parker,D.B., Cole,N.A., Avermann, B.W., and Mehlhorn, J.E., 2001, Surface Amendments To Minimize Ammonia Essions From Deef Cattle Feedlots, American Society of Agricultural Engineers Publication 667-8.

Renken, R. A., 1998. GROUND WATER ATLAS of the UNITED STATES, Ozark Plateau Aquifer System HA-730 F. Available on line at Http://capp.water.usgs.gov/gwa/ch_f/index.html (Date accessed: May 13, 2008)

U.S. EPA "Record of Decision: Residential Areas Operable Unit 2, Tar Creek Superfund Site, Ottawa County, Oklahoma." 1997. Available on line at http://www.epa.gov/earth1r6/6sf/pdffiles/tar-creek-rod-ou2-res.pdf (Date accessed: May 12,2008)

Vandike, J. E., 2001. Rolla's Shrinking Aquifer. No Standing News, Volume 2 Number 76. Available on line at http://www.rollanet.org/~rwnash/nsn_1_76.pdf#search='Ozark%20aquifer'

Websites and web pages

http://www.fws.gov/mountain-prairie/NRDA/CherCO_KS/CherokeeCounty.htm

http://mo.water.usgs.gov/fact_sheets/gndwat.htm

Http://www.phbs.org/independentlens/creekrunsred/film.html

http://www.usda.gov/wps/portal/!ut/p/_s.7_0_A/7_0_1OB?navtype=SU&navid=RURAL_DEVELOPMENT