System Influences & Nutrient Evaluations Education Track
(Morning of October 27)
Reducing phosphorus loading from onsite wastewater treatment systems in the Greenwood Lake Watershed, New York, Bruce Douglas, Stone Environmental, Inc.
An onsite wastewater treatment system (OWTS) demonstration project, funded by the United States Environmental Protection Agency and the New York State Energy Research and Development Authority, is in progress in the Greenwood Lake watershed in Orange County, New York. Elevated phosphorus levels (average 0.031 mg/L) are causing eutrophic conditions in Greenwood Lake. The goal of the project is to demonstrate practices and technologies capable of reducing phosphorus pollution to Greenwood Lake from individual and cluster OWTS, while minimizing electricity consumption.
Greenwood Lake and its approximately 25 square mile watershed span the border of New York and New Jersey. The demonstration project study area is the New York portion of the watershed (approximately 9.2 square miles), which includes the Village of Greenwood Lake and a portion of the Town of Warwick. A Total Maximum Daily Load (TMDL) was approved in 2005 to reduce phosphorus loading from the New York portion of the watershed to Greenwood Lake. This TMDL establishes phosphorus loading reduction targets for stormwater sources and OWTS. Site conditions in the New York portion of the watershed—steep slopes, shallow bedrock and/or groundwater, and generally small lots (average ½ acre)—limit opportunities for effective soil treatment on most parcels. These site conditions were characterized to assess the suitability for OWTS on a neighborhood-by-neighborhood basis. There are approximately 2700 developed parcels in the study area, of which approximately 1500 are within 200 meters of the lake.
Installation of demonstration OWTS is scheduled in the summer of 2010 on two lakeshore properties. One system will incorporate urine diversion to reduce phosphorus loading to the treatment units. The second system will serve a cluster of three buildings and includes advanced secondary treatment followed by a packed bed media filter for phosphorus reduction.
How Ecological Wastewater Treatment Systems Can Improve Larger Ecosystems, William Kirksey, Worrell Water Technologies
Advanced ecological wastewater treatment technology is a viable strategy to address the growing gap between increasing water demand and limited resources to build and maintain infrastructure. Cities, such as Portland, Ore., are working on multi-pronged strategies to extend the life of their water and wastewater systems. Integrating decentralized, ecological wastewater treatment systems reduces strain on the regional infrastructure and limits the need for new construction and upgrades.
This presentation will feature a case study on the Port of Portland’s new headquarters, a recently completed 205,000 sq-ft structure at the Portland International Airport that is a showcase for sustainable practices.
At the centerpiece of this building is the latest generation of advanced ecological wastewater treatment systems, which reduces the facility’s water consumption by treating up to 5,000 gal. of wastewater per day for reuse in the building’s lavatories and for cooling towers. It is a primary component of the building’s water-efficient features that decrease water usage by 75%.
Located in the lobby, the odorless wastewater treatment system offers beautiful indoor landscaping with greenery and ornamental flowers while treating full strength sewage from the building’s toilets and sinks. Under the lush vegetation are treatment cells that are alternately filled and drained to create multiple tidal cycles to cleanse the water. This wastewater treatment system, called the “single most impressive green strategy of the building” by the architect, is an example of biomimicry using advanced ecological engineering combined with 21st century technology
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In addition to the case study, presenters will discuss how this advanced technology can be widely applied to help address the difficult infrastructure and environmental issues facing municipalities.
Watershed-Scale Nutrient Modeling Approaches for Integrated Evaluation of Wastewater Treatment Alternatives, Bruce Douglas, Stone Environmental, Inc.
A consultant team was contracted to study wastewater treatment and nutrient control strategies necessary to meet nitrogen loading reductions in anticipation of nutrient Total Maximum Daily Load (TMDL) enactment for two coastal salt pond watersheds in Rhode Island. A watershed-scale water quality model, the Soil and Water Assessment Toot (SWAT), was used to estimate nitrogen loadings to the salt ponds under several wastewater management scenarios. During development of the SWAT model for this study, modifications were made to the model to allow the input of water and nutrients from onsite wastewater treatment systems at specified depths in the soil profile. Other inputs included nitrogen from stormwater runoff, agricultural fertilization, lawn fertilization, pet waste, atmospheric deposition, organic matter decomposition, and water fowl waste. The modeling approach used in this study allowed a quantitative and transparent comparison between both centralized and decentralized wastewater management alternatives. Modifications to the SWAT model processes developed during this effort improved the simulation of nitrogen loadings from OWTS and can be applied to TMDL development efforts in other areas.
