Working PaperPDF Available
Potential for diverting Mississippi River industrial
discharges to bordering watershed
Michael G. Waldon and Louis Landesman
Louisiana is experiencing rapid coastal land loss and deterioration. Numerous
approaches for protecting and restoring our coast are being investigated and
pursued. Among these approaches is freshwater diversion from the Mississippi
River into the adjacent watersheds. At this time the local, state, and federal
governments are operating freshwater diversions at several locations including
Bayou Lafourche, Violet, and Caernarvon. One obstacle to further development
of diversions is the high capital and operating costs associated with planning,
construction, and operation of such diversions. Diversion of industrial once-
through cooling water could provide a cost-effective means of providing
freshwater to reduce the loss of coastal wetlands and increase wildlife resources in
coastal Louisiana.
Louisiana is experiencing rapid coastal land loss and deterioration. In a recent
issue of the Journal of Coastal Research (Boesch et al. 1994) the authors
concluded the following:
"Net loss of coastal wetlands in Louisiana would probably be occurring
without human intervention in this ecosystem because of the limited
wetland-building potential of the delta presently occupied by the
Mississippi River. However, a variety of human activities have caused
wetland loss to accelerate greatly. These activities include construction of
canals for transportation and oil and gas development and the hydrological
modifications that result from them; impoundments and failed land
reclamation; and interference with flood water flow across the natural
levees of the river. Without mitigation or restoration, the modifications
resulting from these activities will continue to cause high rates of wetland
One possible approach to mitigating loss of coastal land is freshwater diversion
from the Mississippi River into the adjacent coastal watersheds. At this time the
local, state, and federal governments are operating freshwater diversions at
locations including Bayou Lafourche, Violet and Caernarvon. One obstacle to
further development of these diversions is the high capital and operating costs
such diversion structures require. A proposed expansion of the Bayou Lafourche
diversion to 2000 cfs, for example, is expected to cost 24 million dollars for
planning and construction. Diversion of industrial once-through cooling water
could provide a cost-effective augmentation to these costly projects.
Once-through cooling water is utilized by many of the more than 70 industries
(power generation, chemical manufacturing and petroleum refining) located along
the Mississippi River downstream from Baton Rouge. These sectors withdraw and
return approximately 6 billion gallons of water per day (9000 cubic feet per
second) from the Mississippi River mainstream, or roughly 2 percent of the annual
average streamflow (Lovelace, 1991a, 1991b, 1996).
Funded by federal and state appropriations, a significant effort is currently
underway in Louisiana to protect and restore our coastal lands. One element in
this effort is the establishment of freshwater diversions. The Bayou Lafourche
and Teche-Vermilion River diversions have illustrated the potential these projects
can have to improve water quality and water supply (Waldon and Richards, 1992).
The Caernarvon diversion has provided substantial, though anecdotal, evidence of
improvements in fishery production (Waldon and Bryan 1995). Cost-benefit
studies of the Caernarvon and Davis Pond freshwater diversions are available, and
can provide a preliminary basis for valuing the potential wetland enhancement and
protection contributed by other proposed diversion projects. Caernarvon and
Davis Pond have typical diversion flows of 7000 and 4000 CFS, respectively, and
annual benefits of 9.2 and 7.4 million dollars. This implies an annual benefit of
$1,300 and $1,800 per CFS. Thus, a 1000 CFS diversion of once-through cooling
water would likely have a value in excess of one million dollars per year
The redirection of once-through cooling water discharges provides a substantial
and immediate potential for diverting Mississippi River water at little or no cost in
tax dollars. Additionally, providing multiple freshwater diversions along widely
spaced locations is a more environmentally sound configuration than would be
economically achievable using specially constructed pump or siphon projects.
It is anticipated that River industries will adopt the diversion as an improved
method of handling once-through cooling water discharges. Although direct
economic incentives to these industries will vary, we feel that Louisiana industries
are environmentally sensitive and are eager to cooperate in developing
environmental enhancements. The possibility of obtaining wetland mitigation
credit through participation in this program may provide a strong additional
incentive for industrial participation.
The Mississippi River has sediment loads potentially available to offset coastal
subsidence. All of the Louisiana coastal restoration plans include a call for
diversion of significant amounts of Mississippi River discharge away from the
present deep channel. We will examine several industries presently using
Mississippi River water for cooling purposes. These industries presently send their
cooling water with its suspended sediment back into the river. By selecting a few
of the larger diverters as potential candidates for the re-diversion of their cooling
water resources, we will determine how much of this water is available, how much
sediment it will likely contribute to the receiving wetland, and what will be the
total impact on the wetlands that receive this redirected cooling water.
Methods - Typically, River industries are located on the natural river levee (the
high land adjacent to the channel), and behind the protection of the manmade
levee (see figure 1). Water intake pumps lift water over the manmade levee, and
return water pumps lift wastewater over the levee for discharge. For most of the
230 miles of River below Baton Rouge, swamp or marsh wetlands parallel both
banks of the channel. These wetlands have been hydrologically isolated from the
River by construction of the levee system and closure of natural distributaries such
as Bayou Lafourche.
Data on the geographic location of Mississippi River industries has been compiled
in a GIS database by the investigators (Bostock, et al., 1991; Richards, 1992, 1993)
under a contract with the Louisiana Department of Environmental Quality
(LDEQ). A map showing the location of the 10 large industries that may be
candidates for using their cooling water for diverting to neighboring watersheds is
given in figure 2. Table 1 gives a list of these candidate industries, their location
by river mile and parish and the amount of water they presently divert and could
potentially provide. Information on design discharge flow rates and chemical
analyses of discharges are available in public records at the LDEQ headquarters,
but have not been entered into a comprehensive computer database. Data on
internal and final outfalls for each industry will be extracted from the LDEQ files.
These data will be incorporated into the existing Mississippi River GIS which was
developed by the investigators.
The LDEQ has also defined for all waters of the state. These standards include
both narrative criteria and numerical criteria.
The numerical criteria are defined for substances and properties such as
temperature, dissolved solids, hardness, and synthetic organic compounds.
Because of the high critical discharge of the Mississippi River, most bulk
chemical plant NPDES permit limitations for River outfalls are determined by
technology based industry OCPSF guidelines (the Organic Chemical, Plastics and
Synthetic Fibers Effluent Guideline requirements). EPA and LDEQ use a
screening dilution model which calculates water quality based permit loading
(mass per day) limits from receiving stream standards, receiving stream critical
dilution discharge, and outfall design flow. Diverting industrial discharge into
adjoining watersheds may potentially result in more stringent limits for both the
diverted discharge as well as the un-diverted fraction of the discharge. Following
preliminary identification of sites, a water quality screening will be applied to
determine the anticipated impact of diversion on permit limitations.
The EPA has also recently initiated a "Project XL" which may grant exemption
from specific regulatory requirements of the current system at specific facilities
and commits project participants to achieve a higher level of beneficial
environmental results through alternative approaches. The proposed project will
investigate the possibility of application to Project XL at the selected sites.
Database resources are available through state agencies to locate the candidate
industries and their cooling water discharges. Additionally, GIS and other
databases are available at Louisiana academic institutions. In addition a GIS data
system exists at the National Wetland Research Center that describes and predicts
the impact freshwater diversions will have on wetlands receiving this once-
through cooling water (Wei and Mitchell 1995).
Along Louisiana’s Mississippi River industrial corridor, Waste heat from
industrial processes is often transferred to a pumped intake of river water and
discharged using a once-through cooling water process. The once-through water
may impact receiving water through temperature increase and chemical additives,
principally chlorine. Although these impacts could possibly affect a local area
near the cooling water discharge outfall, diversion of discharge away from the
River would likely have significant and broad-scale beneficial impacts. Benefits
could include reduction in salinity, and addition of nutrients and sediments. Thus,
redirection of once-through cooling water to create new river diversions could
help reduce coastal land loss and improve ecological function in basins bordering
the Mississippi River.
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the lower Mississippi River in southeastern Louisiana, 1990
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in the Vermilion River, Louisiana. The Louisiana
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ResearchGate has not been able to resolve any citations for this publication.
Full-text available
Technical Report
Discharge of water from the Mississippi River to the Atchafalaya River at the Old River diversion structures is, by law, regulated to maintain a constant ratio of 70/30 for the discharge of the Lower Mississippi River to the discharge of the Atchafalaya River at a latitude downstream of the control structures. We propose to increase the discharge to the Atchafalaya River during intermediate flow conditions. No change in discharge is proposed under high-flow or low-flow conditions. This modification from the current control strategy will divert a long term average additional flow of 48,000 cfs. This represents a 20% increase in Atchafalaya River discharge and a 29% increase in diversion discharge over present conditions. This additional diversion will have little or no economic or environmental cost, and will provide added freshwater and accelerated accretion of coastal lands. Additionally, the added flow and stage within the Atchafalaya Basin will contribute to the quality of the fishery and to the goal of maintaining a "wet and wild" Atchafalaya Basin. Suggested citation: Waldon, M.G., and C.F. Bryan (1995) “A New Hydrological Regime for the Atchafalaya River to Enhance Fisheries and Coastal Accretion.” Technical Report prepared for the Louisiana Cooperative Fish and Wildlife Research Unit National Biological Service, Baton Rouge, LA.
Full-text available
Water quality in the Vermilion River has been impaired by hydrologic modifications, nonpoint source pollution, and point sources of municipal and industrial waste water discharges. Dissolved oxygen concentration (DO) steadily declined throughout the 1960s and 1970s. This decline was likely caused by two factors: an increase in population and extension of centralized sewage treatment facilities and enhanced sensitivity of the river to pollutant loads because of diminished stream flow which resulted from flood protection projects including the West Atchafalaya Basin Protection Levee. Over the past decade, Vermilion River DO has markedly improved. Improvements in municipal and industrial wastewater treatment’ and flow augmentation through the Teche-Vermilion water diversion appear to be the major factors responsible for the water quality improvements. The success of these pollution control measures provides an example of the potential for effective pollution abatement and mitigation in Louisiana streams. It is concluded that flow augmentation projects may have the potential to provide similar water quality enhancements in other Louisiana bayous and rivers.
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Conference Paper
Under the provisions of the Clean Water Act, water quality modeling plays a central role in development of control strategies for both point and nonpoint pollutants. These pollutants include oxygen demanding substances, toxic chemicals, whole effluent toxicity, nutrients, and pathogens or surrogate organisms. The Act broadly defines procedures for the determination of the 'Total Maximum Daily Load' (TMDL) of pollutants and the allocation of the load between the various natural, nonpoint, and point sources. Federal guidance and Louisiana policies further specify procedures to be followed in water quality management. Water quality models are utilized in the assessment of pollutant sources, pollutant transport, and environmental transformation, as well as in the determination of appropriate load limitations and management practices. Many water bodies in Louisiana have been modeled for these purposes, including the Calcasieu Estuary, the Vermilion River, and Bayou Grand Caillou. Additionally, at the present time, several areas are in some stage of field study or model development. Model selection depends on a variety of factors. At times, steady state models are adequate for the purpose of TMDL development. However, in complex estuarine environments, a dynamic model may most often be required. Special studies are generally required to collect the data necessary to calibrate these models. Studies performed in support of development of these water quality models are termed intensive, or synoptic, surveys. Under estuarine conditions, certain aspects of the design of these studies must be modified and often may gain additional significance. For example, use of a tracer dye can facilitate the assessment of estuarine transport and pollutant transformation. The application of the emerging technology of satellite global positioning systems (GPS) also has been found to provide a needed utility in estuarine locales. For model development, the utilization of a geographic information system (GIS) for site mapping, database support, and spatial segmentation has provided increased efficiency and flexibility. Efforts to develop water quality models, TMDLs. and wasteload allocations for Louisiana estuaries continue. These efforts will not only assist the State in point and nonpoint source pollutant management, but will also provide a basis for better understanding the special characteristics of Louisiana's estuarine water resources.
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The application of a geographic information system (GIS) for protection of drinking water supplies drawn from the lower Mississippi River is described in this paper. Potential sources of contamination of public water supplies resulting from pollutant spills or releases on the Mississippi River are identified by a GIS developed specifically for the Mississippi River Industrial corridor in Louisiana. The G!S includes a relational database, which is geo-referenced through a digitized map of the River. In addition to location, the database includes information on discharger outfalls and drinking water intakes. This paper discusses the development of the digital graphics model and geo-referenced database, and work in progress that will interface the existing graphics and database with a numerical model that estimates the time-of-travel on the River at various flows. Application of the GIS and time-of-travel model programs in surveillance of an actual chemical spill in the River is described.
Full-text available
Oxygen depletion is a seasonally dominant feature of the lower water column on the highly-stratified, riverine-influenced continental shelf of Louisiana. The areal extent of hypoxia (bottom waters ≤2 mg l−1 dissolved oxygen) in mid-summer may encompass up to 9,500 km2, from the Mississippi River delta to the upper Texas coast, with the spatial configuration of the zone varying interannually. We placed two continuously recording oxygen meters (Endeco 1184) within 1 m of the seabed in 20-m water depth at two locations 77 km apart where we previously documented midsummer bottom water hypoxia. The oxygen meters recorded considerably different oxygen conditions for a 4-mo deployment from mid-June through mid-October. At the station off Terrebonne Bay (C6A), bottom waters were severely depleted in dissolved oxygen and often anoxic for most of the record from mid-June through mid-August, and there were no strong diurnal or diel patterns. At the station 77 km to the east and closer to the Mississippi River delta (WD32E), hypoxia occurred for only 50% of the record, and there was a strong diurnal pattern in the oxygen time-series data. There was no statistically significant coherence between the oxygen time-series at the two stations. Coherence of the oxygen records with wind records was weak. The dominant coherence identified was between the diurnal peaks in the WD32E oxygen record and the bottom pressure record from a gauge located at the mouth of Terrebonne Bay, suggesting that the dissolved oxygen signal at WD32E was due principally to advection by tidal currents. Although the oxygen time-series were considerably different, they were consistent with the physical and biological processes that affect hypoxia on the Louisiana shelf. Differences in the time-series were most intimately tied to the topographic cross-shelf gradients in the two locations, that is, station C6A off Terrebonne Bay was in the middle of a broad, gradually sloping shelf and station WD32E in the Mississippi River Delta Bight was in an area with a steeper cross-shelf depth gradient and likely situated near the edge of a hypoxic water mass that was tidally advected across the study site.
From the 1930s to 1990, the coastal zone of Louisiana lost an estimated 3,950 square kilometers, or 1,526 square miles, of wetlands (i.e., periodically flooded land containing emergent vegetation. This loss of wetlands resulted, for the most part, from inundation or erosion of wetlands rather than from the draining or filling characteristic of many wetland losses elsewhere. In addition, large areas of brackish and freshwater wetlands have become progressively more saline as salt water has increasingly invaded the deteriorating coastal zone. Because 40% of U.S. coastal wetlands are found in Louisiana, this loss constitutes about 80% of the total national coastal wetland loss. Louisiana coastal wetlands are exceptionally valuable in terms of coastal fisheries and migratory waterfowl, protection of low-lying population centers from hurricanes and other storms, and oil and gas production. Furthermore, the greatly accelerated rates of coastal wetland loss appear to be the unintended result of massive human disturbances of these wetlands and intervention (for purposes of flood protection, water supply, maritime commerce, energy production, and wildlife management) in the processes that sustain coastal wetlands... (Full article is available from the Jstore archive -
Prior to cultural development in the Mississippi River Basin, the main stem was a heavy sediment carrier due to the character of the climate and soils in the basin. The placement of flood control structures and other channel improvement features and the implementation of improved land management practices have significantly changed the suspended-sediment flow regime of the main stem. The estimated annual sediment yield of the basin is 900 million (817 million metric) tons. That portion of the yield passing into the Gulf of Mexico, as monitored at suspended-sediment sample collection stations near the mouths of the Mississippi and Atchafalaya rivers, totaled 434 million (394 million metric) tons prior to 1963; however, this value has now declined to 225 million (204 million metric) tons. Long-term trends in the bed material gradation of the Lower Mississippi downstream from the mouth of the Arkansas River have remained relatively constant; however, from Donaldsonville, Louisiana, downstream to Head of Passes, there has been a pronounced shift from the sand to silt fraction.
Loss of Louisiana's coastal wetlands has reached catastrophic proportions. The loss rate is approximately 150 km2/yr (100 acres/day) and is increasing exponentially. Total wetland loss since the turn of the century has been almost 0.5 million ha (1.1 million acres) and represents an area larger than Rhode Island. The physical cause of the problem lies in man's attempts to control the Mississippi River's flooding, while enhancing navigation and extracting minerals. Levee systems and control structures confine sediments that once nourished the wetlands to the river channel. As a consequence, the ultimate sediment deposition is in deep Gulf waters off the Louisiana coast. The lack of sediment input to the interdistributary wetlands results in an accretion deficit. Natural and human-induced subsidence exceeds accretion so that the wetlands sink below sea level and convert to water. The solution is to provide a thin veneer of sediment (approximately 0.6 cm/yr; an average of 1450 g m−2 yr−1) over the coastal marshes and swamps and thus prevent the submergence of vegetation. The sediment source is the Mississippi River system. Calculations show that 9.2% of the river's annual suspended sediment load would be required to sustain the deltaic plain wetlands. It should be distributed during the six high-water months (December–June) through as disaggregated a network as possible. The problem is one of distribution: how can the maximum acres of marsh be nourished with the least cost? At present, the river is managed through federal policy for the benefit of navigation and flood control. A new policy structure, recognizing the new role for the river-sediment distribution, is recommended.