Projects

Miami-Dade Wastewater High Level Disinfection Project

Hazen and Sawyer was retained by Miami-Dade County to provide fast-track planning, design, and construction administration for a 285-mgd high level disinfection (HLD) facility. The motivating force behind this project was a landmark Consent Decree, stipulating that the facility must be completed within five years and also meet FDEP HLD reuse standards, as well as primary drinking water standards.

Project Outcomes and Benefits

• Upgrades the South District Wastewater Secondary Treatment Plant to a 285-mgd HLD facility, creating the largest wastewater facility in the State of Florida that treats to stringent reclaimed water standards.
• To meet the aggressive project schedule, Hazen and Sawyer implemented an intensive project management program, ensuring that goals were achieved quickly and completely.
• The project involved close coordination with the FDEP, completion of a comprehensive pilot program, and preparation of a compliance action plan for nitrite control.

Under Phase 1, effluent will be used for a variety of reuse projects, including on-site spray irrigation, electrical cogeneration cooling water, and treatment plant process water. Under Phase 2, this reclaimed water will be further treated for more advanced uses, such as groundwater recharge for indirect potable reuse, or potentially as a source of fresh water replenishment to the Biscayne Bay under the Comprehensive Everglades Restoration Plan (CERP).

Hazen and Sawyer is providing planning, pilot testing design, and construction administration services for Phase 1, which includes over $500 million worth of capital improvements. The County has recently initiated Phase 2 of the reuse program, involving the use of approximately 23 mgd of effluent from the HLD facility as feedwater for an advanced groundwater recharge application. This facility will treat wastewater to ultra pure standards, surpassing even drinking water criteria. In addition to reverse osmosis membranes, this treatment facility will utilize high-intensity ultraviolet light and hydrogen peroxide, an advanced oxidation process, to destroy microconstituents, including NDMA, pharmaceuticals, hormonally active compounds, and other residual contaminants.

Once completed, the plant will play a crucial role in supporting numerous reuse projects – and will further preserve and protect Florida’s valuable water resources.