Application of statistical modeling to optimize a coastal water quality monitoring program

The long-term water quality monitoring program implemented by the Massachusetts Water Resources Authority in 1992 is extensive and has provide substantial understanding of the seasonality of the waters in both Boston Harbor and Massachusetts Bay and the response to improvements in effluent quality and offshore transfer of the effluent in September 2000. The monitoring program was designed with limited knowledge of spatial and temporal variability and long-term trends within the system. This led to an extensive spatial and temporal sampling program. The data through 2003 showed high correlation within physical parameters measured (e.g., salinity, dissolved oxygen) and in biological measures such as chlorophyll fluorescence. To address the potential sampling redundancies in the measurement program, an assessment of the impact of reduced levels of monitoring on the ability to make water quality decisions was completed. The optimization was conducted by applying statistical models that took into account whether there was evidence of a seasonal pattern in the data. The optimization used model survey average readings to identify temporal fixed effects, model survey-average-corrected individual station readings to identify spatial fixed effects, corrected the individual station readings for temporal and spatial fixed effects and derived a correlation model for the corrected data, and applied the correlation model to characterize the correlation of annual average readings from reduced monitoring programs with true parameter levels. Reductions in the number of sampling stations were found less detrimental to the quality of the data for annual decision-making than reductions in the number of surveys per year, although there is less of a difference in this regard for dissolved oxygen than there is for chlorophyll. The analysis led to recommendations for a substantially lower monitoring effort with minimal loss of information. The recommendation supported an annual budget savings of approximately $183,000. Most of the savings was from fewer surveys as approximately $21,000 came from the reduction in the number of stations monitored from 21 to 7 and associated laboratory analytical costs.     

Flow‐Biology Relationships Based on Fish Habitat Guilds in North Carolina

The health of freshwater biota is dependent on streamflow, yet identification of the flow regimes required to maintain ecological integrity remains challenging to states in the United States seeking to establish ecological flows. We tested the relationship between decreases in streamflow and Shannon‐Weaver diversity index of fish species for four flow‐based habitat guilds: riffle, riffle‐run, pool‐run, and pool in North Carolina. We found species that prefer shallow habitats, such as riffles and riffle‐runs were the most sensitive to decreases in streamflow; whereas no significant relationships were found for pool or pool‐run species. The sensitivity to decreases in streamflow was greatest during summer and fall, when streams are naturally lower. When all fish habitat guilds were included in the assessment of flow‐biology relationships, there were no significant relationships to decreases in streamflow. As the sensitivity of fish to reductions in streamflow is not constant across habitat guilds, combining all fish species together for flow‐biology analyses may greatly underestimate the response of fish species to decreases in flow and should be acknowledged when establishing ecological flows.     

Antioxidants in Capsicum chinense: Variation among countries of origin

The main objective of this investigation was to evaluate fruits of C. chinense accessions for their concentration of β -carotene, ascorbic acid, and phenols for use as parents in breeding for these phytochemicals. Mature fruits of 63 accessions of C. chinense originally acquired from Belize, Brazil, Colombia, Ecuador, Mexico, Peru, Puerto Rico, and the United States were analyzed for their chemical composition. Fruits of C. chinense accessions PI-152452 (Brazil) and PI-360726 (Ecuador) contained the greatest concentrations of ascorbic acid (1.2 and 1.1 mg g^?1 fresh fruit, respectively), while PI-438648 (Mexico) contained the greatest concentration of total phenols content (349 μ g g^?1 fresh fruit) among the other 63 accessions tested. Accession PI-355817 from Ecuador contained the greatest concentrations of β -carotene (8 mg g^?1fresh fruit). These accessions were identified as potential candidates for mass production of antioxidants with health-promoting properties.     

Hazardous Waste Minimization: Part IV Waste Reduction in the Metal Finishing Industry

The metal finishing industry uses over 40 production processes to produce a wide range of metal products. Waste streams generated include wastewater, waste oils, spent solvents, and spent process solutions. Currently a wide variety of techniques which minimize waste are available. Cost-effective methods to reduce electroplating wastewater contamination include water conservation and drag-out reduction, recovery and management. Ways to cost-effectively reduce the generation of spent metal-working fluids include establishing a fluid management program and installing a fluid recovery system. However, before any techniques are selected, a waste reduction survey should first be conducted.     

Precision placement of separated dairy sludge improves early phosphorus nutrition and growth in corn ( L.)

Efficient use of manure nutrients by crops is necessary to minimize losses to the environment. This field study examined the possibility of replacing side-banded mineral P with precision-placed high-P sludge (6.2-11.0% dry matter) obtained after settling dairy manure slurry. The sludge was injected at about 30 kg P ha (36.0-51.2 m ha) into the soil at corn row spacing, and the corn was planted 5, 10, and 15 cm beside the injection furrow. Controls included no added P and side-banded commercial P fertilizer. The treatments were tested on corn with low and high root colonization by arbuscular mycorrhizae (AM). The study showed that sludge did not impede AM root colonization, corn germination, or seedling growth. Corn plants with both high and low levels of AM colonization responded to the sludge from the three-leaf stage and showed the greatest benefit at the six-leaf stage. Corn responded more to sludge placed at 5 than at 15 cm from the corn rows, whereas the response at the 10-cm spacing was intermediate. There was little difference in seedling growth or final harvest parameters between the side-banded fertilizer P and the 5-cm sludge treatment. The results show a new way to use manure nutrients, namely precision-placement sludge for corn. This may obviate the need for chemical fertilizers for improving farm nutrient balances. Other anticipated benefits are less energy use for hauling and injection of the sludge fraction and reduced risk of nutrient loss by runoff and volatilization (ammonia) and nuisance odors due to injection.     

A Question of Boundaries: The Importance of “Revenuesheds” for Watershed Protection1

Patterson, Lauren A., Jeffrey Hughes, Glenn Barnes, and Stacey I. Berahzer, 2012. A Question of Boundaries: The Importance of “Revenuesheds” for Watershed Protection. Journal of the American Water Resources Association (JAWRA) 48(4): 838‐848. DOI: 10.1111/j.1752‐1688.2012.00655.x Abstract: Watersheds transcend jurisdictional boundaries; raising important questions of who should pay for watershed protection, and how can watershed governance be funded? The responsibility and cost for watershed protection has progressively devolved to local governments, resulting in additional negative externalities and financing challenges. Watershed governance structures have formed at the scale of the watershed, but they often lack the financing mechanisms needed to achieve policy goals. Financing mechanisms via local governments provide a reliable source of revenue and the flexibility to address watershed specific issues. We develop a “revenueshed” approach to access the initial challenges local governments face when seeking to finance trans‐jurisdictional watershed governance. The revenueshed approach engages local governments into discussion and implementation of financial strategies for collaborative watershed governance. Legislation places water quality regulations primarily on local governments inside the watershed. The revenueshed approach extends the financial and stewardship discussion to include local governments outside the watershed that benefit from the watershed. We applied the revenueshed approach to the Mills River and Upper Neuse watersheds in North Carolina. Mills River had a partnership governance seeking revenue for specific projects, whereas the Upper Neuse sought long‐term financial stability to meet new water quality legislation.     

Denitrification in anaerobic lagoons used to treat swine wastewater

Anaerobic lagoons are commonly used for the treatment of swine wastewater. Although these lagoons were once thought to be relatively simple, their physical, chemical, and biological processes are very complex. This study of anaerobic lagoons had two objectives: (i) to quantify denitrification enzyme activity (DEA) and (ii) to evaluate the influence of lagoon characteristics on the DEA. The DEA was measured by the acetylene inhibition method. Wastewater samples and physical and chemical measurements were taken from the wastewater column of nine anaerobic swine lagoons from May 2006 to May 2009. These lagoons were typical for anaerobic swine lagoons in the Carolinas relative to their size, operation, and chemical and physical characteristics. Their mean value for DEA was 87 mg N2O-N m(-3) d(-1). In a lagoon with 2-m depth, this rate of DEA would be compatible with 1.74 kg N ha(-1) d(-1) When nonlimiting nitrate was added, the highest DEA was compatible with 4.38 kg N ha(-1) d(-1) loss. Using stepwise regression for this treatment, the lagoon characteristics (i.e., soluble organic carbon, total nitrogen, temperature, and NO3-N) provided a final step model R2 of 0.69. Nitrous oxide from incomplete denitrification was not a significant part of the system nitrogen balance. Although alternate pathways of denitrification may exist within or beneath the wastewater column, this paper documents the lack of sufficient denitrification enzyme activity within the wastewater column of these anaerobic lagoons to support large N2 gas losses via classical nitrification and denitrification.     

interpretation of air quality data with respect to the national ambient air quality standards

San Diego Gas &; Electric has developed a quality assurance program for continuous emission monitors (CEM). Extractive, rather than in situ, monitors were selected as a result of an in-house evaluation program. Two extractive systems have been certified and a good operating and maintenance record has been established on these systems. A successful program requires the involvement and support of all affected personnel. It is desirable to have one or two key personnel coordinate the development of the program. It is also highly desirable to have good in-house source testing capabilities.