Tozer H.,Woodard and Curran Inc.
Journal of New England Water Environment Association | Year: 2014
Many industrial wastewater treatment plants use coagulation and flocculation to remove phosphorus, heavy metals, and other solids that would not practically settle in conventional clarifiers. The successful design and operation of these systems must consider the wastewater characteristics, treatment chemistries, mixing, solids recycle, and testing.
Aigler B.V.,Woodard and Curran Inc. |
Ge S.,University of Colorado at Boulder
Environmental Earth Sciences | Year: 2013
The purpose of this study is to evaluate the groundwater-withdrawal potential of the Fraser River watershed, a mountainous drainage system in north-central Colorado. Laboratory tests, field investigations, and numerical modeling are conducted to present a quantitative understanding of the watershed's groundwater-flow system. Aquifer hydraulic conductivity values obtained from aquifer tests range from 1E-5 to 1E-3 m/s. Groundwater withdrawal is concentrated in channel-fill deposits of the Troublesome Formation within the Fraser basin. A steady state groundwater-flow model of the Fraser River watershed is developed and calibrated using 24 observation wells in the Fraser River valley and estimated baseflow of the Fraser River. Modeling results suggest that surface recharge is the major source of groundwater in the watershed. Groundwater exits the watershed through evapotranspiration and discharge to rivers. Transient groundwater-flow modeling evaluates future withdrawal scenarios using the hydraulic head distribution from the steady state model as the initial condition. Drawdown within Troublesome Formation aquifers from the current pumping schedule approaches 2 m. When the daily pumping rate is doubled, drawdown approaches 4 m. The radius of influence is hundreds of meters to 1 km. Pumping wells withdraw approximately 2 and 15 % of groundwater flowing through the well field for hydraulic conductivity of 1E-3 and 1E-5 m/s, respectively. This study suggests that the groundwater system at the Fraser Valley could sustain current and future withdrawals, given that the current recharge condition is maintained. © 2012 Springer-Verlag Berlin Heidelberg.
Feldman P.,Woodard and Curran Inc. |
Suttles J.,Woodard and Curran Inc.
Journal of the New England Water Works Association | Year: 2011
Water resources planning - planning for a utility's future to provide appropriate water, wastewater and stormwater services - has changed over the past several decades, particularly as Georgia has faced the challenges of both significant growth as well as resource constraints. With the economic slow-down, it's a perfect time for utilities to take a breath, assess conditions and establish a road map for the future that incorporates proactive policies to enhance efficiency and promote sustainability.
Dombrowski P.,Woodard and Curran Inc. |
Hanafi A.,Woodard and Curran Inc. |
Kuczarski G.,Windsor Locks WPCF |
Sciarrino T.,Windsor Locks WPCF |
Persson R.,Windsor Locks WPCF
Journal of New England Water Environment Association | Year: 2016
The Windsor Locks, Connecticut Water Pollution Control Facility (WPCF) has implemented a dual operating mode (DOM) configuration of the Modified Ludzack-Ettinger (MLE) process to improve both total nitrogen (TN) removal and wet weather capacity. The facility implemented a step-wise approach to determine: (1) capacity of the system and key operating parameters in nitrogen removal mode; (2) when the system will need to convert operation into a wet weather mode of operation; (3) system capacity in wet weather mode; and (4) flow condition at which the system can safely switch back into the nitrogen removal mode of operation. Changes in operating mode and improved operator understanding of the capabilities of the process have reduced TN by approximately 50 percent compared to prior MLE operation as well as reduced staffing requirements during wet weather events.