ERD Clients and Projects


Apopka Beauclair Canal Alum Treatment Reduction Facility (NuRF)

CLIENT: Lake County Water Authority (LCWA)
CONTACT: Lance Lumbard, Water Resources Project Manager - (352-343-3777, x38)
PROJECT DATES: March 2004-2009
PROJECT DIRECTOR: Dr. Harvey H. Harper, P.E.


Location Map for the LCWA NuRF SiteDuring June 2003 Environmental Research & Design, Inc. (ERD) was selected by the LCWA to evaluate and design perform a feasibility study and engineering design for an off-line alum stormwater treatment system on the Apopka-Beauclair Canal to provide treatment for discharges from Lake Apopka into the Harris Chain-of-Lakes. Discharges through the Apopka-Beauclair Canal contribute more than 90% of the phosphorus loadings to Lake Beauclair and comprise the single largest input into the entire Chain-of-Lakes.

Preliminary Design work efforts included:

  1. Evaluation of the historic and current project site conditions
  2. Hydrologic characterization and modeling of historic canal discharges to establish design parameters
  3. Collection of canal samples and laboratory jar testing to evaluate the feasibility of alum for nutrient reduction
  4. Estimation of annual mass loadings of TP discharging through the canal
  5. Evaluation of the feasibility of using alum to maximize removal of total phosphorus

The collected canal samples were evaluated in a series of laboratory jar tests to determine the optimum alum treatment dose and evaluate settling characteristics. A conceptual design was developed which includes facilities for alum injection, inflow and outflow channels, floc collection in two large dedicated settling ponds, alum storage tanks and containment, floc dewatering using a large centrifuge, a storage area for dried floc, and ancillary facilities. The system also includes two dedicated hydraulic dredges which provide automated floc removal.

Schematic of LCWA NuRF SystemThe design uses the natural hydraulic gradient created by an existing lock and dam structure located adjacent to the site to divert water into the treatment area which avoids the need for pumps to bring water into the system. The unit removal costs for phosphorus are substantially lower than can be achieved with conventional treatment systems.

ERD prepared and submitted a FDEP permit application for the project and prepared construction drawings, technical specifications, contract documents, and opinions of probable construction costs at 60%, 90%, and 100% completion milestones. The designed system is the largest alum treatment system in existence and the first to use a centrifuge to dewater alum floc. The treatment system is capable of providing alum treatment for inflows up to 300 cfs which is sufficient to treat more than 85% of the annual discharges through the Apopka-Beauclair Canal. Anticipated alum use is 1.5-3 million gallons per year with a peak use of 38,000 gal/day at the design flow rate. ERD provided construction administration and oversight and assisted the Owner in evaluating change order requests. Construction cost for the treatment system was 7.2 million dollars.


  • Detailed review of hydrologic and hydraulic characteristics of the Apopka-Beauclair Canal system and review of historic discharges to establish design parameters and estimate pollutant removal efficiency
  • Collection of canal samples and laboratory testing to evaluate optimum chemical dose and floc generation rates
  • Estimation of annual mass loadings of total phosphorus discharging through the canal and anticipated annual mass removals
  • Preparation of opinions of cost, annual O&M requirements, annual O&M cost, and 20-year present worth
  • Estimated annual mass loading reductions for total phosphorus in the proposed alum treatment system
  • Preparation of construction drawings, technical specifications, contract documents, and opinions of cost at the 60%, 90% and 100% completion milestones
  • Preparation of the FDEP ERP Permit Application
  • Construction administration and oversight




Clients & Projects















































Home  |  About  |   Services  |  Clients & Projects  |  Publications  | Staff  |   Contact

© 2018 ERD Environmental Research & Design
3419 Trentwood Blvd., Suite 100, Orlando, FL - USA 32812-4863
Phone: (407) 855-9465, Fax: (407) 826-0419, e-mail: