Ellen Z. Harrison

Sedimentation Rates on Tidal Salt Marshes in Connecticut

ABSTRACT Rates of sediment accretion from 1963-1973 on five high marsh sites on the Connecticut coast of Long Island Sound ranged from 2.0 mm/yr to 6.6 mm/yr. The rates are correlated with tidal range; the highest sedimentation rates are on marshes with the greatest tidal range. The greater the tidal range, the larger are the deviations of high-tide level. Thus, greater net flooding occurs on high marshes with greater tide ranges and may cause the observed high accretion rates. Over ten years no measurable compaction has taken place within the near-surface sediment. Years with fewer than average storms show less sediment accretion. A sedimentation rate of 17.1 mm/yr from 1963-1973 was measured where Spartina patens salt marsh is giving way to Phragmites communis.

Land Application of Sewage Sludges: An Appraisal of the US Regulations

This paper was published in the peer reviewed INT. J. OF ENVIRONMENT AND POLLUTION, 1999, Vol. 11 No. 1 pp 1-36. The journal is available in both hard copy and on-line PDF format. For more information and sample copy of IJEP, visit their web site at http://www.inderscience.com/.

INVESTIGATION OF ALLEGED HEALTH INCIDENTS ASSOCIATED WITH LAND APPLICATION OF SEWAGE SLUDGES

The majority of U.S. sewage sludges are disposed by application to land for use as a soil amendment. Class B sludges, containing a complex mix of chemical and biological contaminants, comprise the majority. Residents near land application sites report illness. Symptoms of more than 328 people involved in 39 incidents in 15 states are described. Investigation and tracking of the incidents by agencies is poor. Only one of 10 EPA regions provided substantial information on the incidents in their region. Investigations, when conducted, focused on compliance with regulations. No substantial health-related investigations were conducted by federal, state, or local officials. A system for tracking and investigation is needed. Analysis of the limited data suggests that surface-applied Class B sludges present the greatest risk and should be eliminated. However, even under less risky application scenarios, the potential for off-site movement of chemicals, pathogens, and biological agents suggests that their use should be eliminated.

Municipal solid waste composting: Policy and regulation

Abstract Municipal Solid Waste (MSW) composting is a rapidly evolving technology, and as such is subject to shifting policies and changing regulations. Composting is a viable way of recycling organic wastes which comprise a large fraction of the municipal solid waste stream, but there is debate about whether compost inputs should be restricted to source separated “biowastes” or whether centralized processing of mixed solid waste is acceptable. Several additional key policy issues include: how MSW composting fits into an integrated waste management system; compost quality standards and restrictions on compost utilization; facility siting, design, and operation; and regulatory enforcement. As with other policies and regulations, those related to MSW composting are influenced by a combination of science, economics, and philosophy as mediated by the political process. Current MSW compost regulations in North America and Europe provide examples of widely differing policy frameworks and the standards and criteria which result. Risk-based assessments drive compost standards in the United States, while a policy of “no net degradation” of existing soil quality is the basis for standards in parts of Europe and Canada. These different policies result in large differences in the allowable levels of some heavy metals. Unrestricted use of “clean” composts meeting quality standards is generally allowed under all regulations, but restrictions on the use of composts which may contain levels of one or more contaminant that exceed those standards vary. The underlying differences between these frameworks are described, and important uncertainties which research can help resolve are discussed.

Effectiveness of Composting Road-Killed Deer In New York State

Composting of deer carcasses was effective in reducing pathogen levels, decomposing the carcasses and producing a useable end product after 12 months. The composting process used in this project involved enveloping the carcasses of road-killed deer in woodchips and allowing those piles with natural air circulation to sit undisturbed. Temperatures were measured and samples from the piles were analyzed periodically for pathogens and for compost parameters. While significant pathogen reduction occurred in several months, it took 12 months for all of the measured pathogens to decline to low levels in all of the 6 piles studied. Samples taken at other sites in New York State that have been composting road-killed deer for over a year also had low pathogen content. We thus suggest a composting duration of 12 months before use. In the interest of being cautious, we also recommend that the end product be used in low public contact settings such as highway rights-of-way.