The 75 MGD Little Falls Water Treatment Plant in Totowa, New Jersey, required process
improvements to enable it to meet the Stage 2 D/DBP regulations as well as other long term raw
water quality problems. The source water originates in forested watersheds, but also receives
numerous wastewater discharges upstream from the plant intake. Because this is an urban
watershed, the raw water quality can vary considerably from month to month, day to day, and at
times even hour to hour. Principal contaminants of concern are disinfection byproduct
precursors, pathogenic organisms, turbidity, algae, taste and odor, organic compounds, iron and
manganese, and nutrients.
The retrofit design was developed to maximize the utility of both existing and new treatment
facilities within the limited site. A major change is the use of a compact ballasted flocculation
system to replace the function of the existing sedimentation basins. This is the largest (120
MGD) ballasted flocculation potable water plant in the United States. In addition, ozone will be
applied to meet the full range of oxidation and disinfection goals for the project and is followed
by deep bed biological filtration.
As part of the design scope of this upgrade, the Black & Veatch/Hatch Mott MacDonald team
designed, constructed, and operated a 0.2 mgd Actiflo pilot plant at 30 gpm/sq. ft. and as high as
42 gpm/sq. ft. Additionally, the pilot facility was equipped with an ozone contactor and
biological filters.
The paper discusses the successful optimization of the ballasted flocculation process for the
removal of turbidity with respect to polymer, microsand size, and coagulant. Demonstration
testing was performed in 2001 and side-by-side comparison studies with the full-scale facility
were performed in 2003. The evaluation determined that the pilot facility underestimated
turbidity removal and required greater polymer and coagulant doses. The pilot facility is
currently being used to optimize the full-scale for economical operations and as an indicator for
changes in water quality that require modifications to plant operation. Includes tables, figures.
| Edition : | Vol. - No. |
| File Size : | 1
file
, 1.1 MB |
| Note : | This product is unavailable in Ukraine, Russia, Belarus |
| Number of Pages : | 11 |
| Published : | 11/02/2003 |
