SETTING AN EFFECTIVE TMDL: SEDIMENT LOADING AND EFFECTS OF SUSPENDED SEDIMENT ON FISR1

ABSTRACT: The Agricultural Drainage and Pesticide Transport model was used to examine the relationship between fish and suspended sediment in the context of a proposed total maximum daily load (TMDL) in two agricultural watersheds in Minnesota. During a 50‐year simulation, Wells Creek, a third‐order cold water stream, had an estimated 1,164 events (i.e., one or more consecutive days of estimated sediment loading) and the Chippewa River, a fourth‐order warm water stream, had 906 events of measurable suspended sediment. Sublethal thresholds were exceeded for 970 events and lethal levels for 194 events for brown trout in Wells Creek, whereas adult nonsalmonids would have experienced sublethal levels for 923 events and lethal levels for 241 events. Sublethal levels were exceeded for 756 events and lethal thresholds were exceeded for 150 events in the Chippewa River. Nonsalmonids would have experienced 15 events of mortality between 0 and 20 percent in Wells Creek. In the Chippewa River, there were 35 events of mortality between 0 and 20 percent and one event in which mortality could have exceeded 20 percent. The Minnesota Pollution Control Agency has proposed listing stream reaches as being impaired for turbidity at 25 NTU, which is approximately 46 mg suspended sediment/1. We estimated that 46 mg/1 would be exceeded approximately 30 days in a year (d/yr) in both systems. A TMDL of 46 mg SS/1 may be too high to ensure that stream fishes are not negatively affected by suspended sediment. We recommend that an indicator incorporating the duration of exposure be applied.     

SUSTAINING LOCAL WATERSHED INITIATIVES: LESSONS FROM LANDCARE AND WATERSHED COUNCILS1

ABSTRACT: In the last decade, watershed groups (WG) established through government initiatives have become an important part of the natural resource management landscape in developed economies. In this paper, the authors reflect upon their research and experience with Landcare in Victoria, and to a lesser extent with Watershed Councils in Oregon, to identify the principles that appear fundamental to sustaining effective WG. In the first instance, these groups must be established at a local scale using social as well as biophysical boundaries. It is also critical that WG are embedded within a supportive institutional framework that identifies realistic roles for private landowners, local organizations such as WG, and regional planning bodies. Without broad stakeholder representation, the perceived benefits of participation are quickly forfeited. It is simply unrealistic to expect an effective network of WG to be sustained without substantial investment by government to provide for program management, group coordination, and cost sharing for on‐ground work. There must also be the commitment and skills within a program to establish processes that build trust and competency amongst citizens and agencies. These principles should also provide a foundation for the critical evaluation of WG programs.     

STREAM DEPTH SIGNIFICANCE DURING IN‐SITU SEDIMENT OXYGEN DEMAND MEASUREMENTS IN SHALLOW STREAMS1

ABSTRACT: Ninety‐one sediment oxygen demand (SOD) samples from six designated sites along the stretch of Lower Rapid Creek, South Dakota, were conducted using an in‐situ SOD chamber. Inside the chamber, readings of dissolved oxygen (DO), water temperature, pH, and specific conductance were recorded every minute for more than one hour using the Datasonde 3 Hydrolab. Initial readings of such parameters were recorded for the overlaying water before the deployment of the SOD chamber. Characteristics of the stream conditions, air temperature, barometric pressure, average flow velocity of the stream, depth of the stream, and the flow velocity by the chamber were recorded. Single and multiple linear regression analyses on all parameters indicated that the velocity of the stream is the least critical parameter for SOD in shallow streams.     

The effect of other orientation on self–supervisor rating agreement

Employees generally rate their performance more favorably than do their supervisors, which can lead to conflict and poor job performance. However, comparative international research indicates that persons from other‐oriented collectivist cultures are less self‐enhancing, suggesting that other‐oriented employees will exhibit greater agreement with ratings provided by their supervisors. We examined the effect of subordinates' other orientation on self‐supervisor performance rating agreement. Consistent with cultural expectations, self‐ratings of other‐oriented subordinates showed greater agreement with ratings provided by their supervisors and less leniency relative to their supervisors' evaluations. These findings have implications for understanding how employees in different professions, organizations, and cultures utilize feedback from their supervisors. Copyright © 2004 John Wiley & Sons, Ltd.     

RCRA corrective action costs: An estimating model for nonfederal facilities

This article presents an analysis of the prospective costs of RCRA corrective action for private, nonfederal facilities. Two data bases developed by Research Triangle Institute and a remedial action cost model developed by CH2M Hill provide the foundation for this work. The methodology has two components, a remedial action knowledge base and a discrete-state Monte Carlo analysis. Under base case assumptions, it is estimated that the total costs of RCRA corrective action will be $240 billion, with a 5 percent chance the costs will be less than $170 billion and a 5 percent chance the costs will be more than $377 billion.     

THE DEVELOPMENT AND IMPLEMENTATION OF A GIS-BASED CONTAMINANT SOURCE INVENTORY OVER THE SPOKANE AQUIFER,SPOKANE COUNTY WASHINGTON1

ABSTRACT: U.S. Environmental Protection Agency (EPA) statutes require identification of all potential sources of contamination within a wellhead protection area. All wells over Spokane County's aquifer are included in one wellhead protection zone called the Aquifer Sensitive Area (ASA). A GIS-based Contaminant Source Inventory (CSI) was developed for the ASA. Datasets listing businesses and agencies within the ASA were imported into the GIS from state, county, city, and local agencies. These datasets were selected, joined, and sorted using GIS relational database capabilities into one ASA “business master file.” Map files were projected and transformed into common coordinates. Next, business sites within the master file were spatially related by address to the digital map files. Likely Critical Materials Users (CMU) were identified by sorting on selected standard Industrial Codes (SIC). Additional files of CMUs were imported into the Contaminant Source Inventory. GIS queries were performed to locate specific materials, quantities, and storage facilities, and to analyze CMU activity within selected buffer zones. This project demonstrated the usefulness of GIS technology in the development, management, maintenance, and analysis of vast quantities of data associated with a local wellhead protection pro. gram.     

Flood hazard assessment for land-use planning near desert mountains

Metropolitan areas located in arid and semiarid environments are rapidly expanding onto the piedmonts of nearby desert mountains. Hazards to urban development are posed by the complex fluvial systems that characterize these environments, yet no generally accepted methodology exists for evaluating flood hazards on desert piedmonts. An approach to flood hazard assessment is presented that involves the hydrogeomorphic analysis of land surfaces. Five flood hazard zones are identified for an area in central Arizona by analyzing the spatial variation of landforms and their associated fluvial processes. The methodology is applicable to similar environments elsewhere because it is based on the identification of forms and processes common to arid regions. The information provided by the analysis can form the basis for a comprehensive flood hazard management plan.     

THE STATUS OF NONPOINT SOURCE POLLUTION: ITS NATURE,EXTENT AND CONTROL1

Nonpoint source pollution remains as the primary reason for the designation of many of the Nation's streams as “water quality limited.” This means that even with the application of technology-based effluent limitations on point sources, ambient water quality standards will not be met. This paper explores several of the reasons why nonpoint sources are so difficult to come to grips with. These reasons include: (1) the inability to expand the definition of nonpoint sources to encompass nonengineering attributes, (2) the relatively primitive state of characterizing nonpoint sources, (3) the lack of prior success in conducting programs to study and alleviate nonpoint problems, and (4) an uncertain approach to providing incentives for control practices.