MWH provided evaluation services and is providing construction oversight for the deepest permitted injection wells in the state of Florida.
The Tampa Electric Company (TEC) is investigating deep well disposal in rural Polk County Florida to dispose of concentrate from reverse osmosis treatment of reclaimed water for additional process water supply at the facility and facility wastewater process flows. The exploratory injection well was designed as the deepest permitted injection well in the state of Florida. This well is initially permitted as a Class V exploratory well to investigate the Upper Cretaceous formations for potential injection zones. Once a suitable injection zone was identified, the well is being repermitted as a Class I deep injection well. MWH is providing injection well construction oversight of the second injection well for the Tampa Electric Company.
The injection well IW-1 was initially permitted to be construction to 6,000 feet below land surface (bls) with injection zones into the Upper Cretaceous lower Cedar Keys and Lawson Formations. It was later extended to 8,000 feet bls to evaluate deeper formations for additional permeability. Initial injection capacity evaluations indicate that the first injection well will be able to accept all of the injection flows of approximately 1.3 million gallons per day. The second injection well, Well IW-2, is currently being added at the Polk Power Station site for redundancy in the water disposal system. It is also being evaluated for a carbon sequestration through a pilot project.
MWH is providing continuous well construction oversight for this exploratory well project with over 16 months of continuous construction for the first injection well system. The second injection well is expected to take approximately 2 more years to complete. The oversight tasks include submittal review, well design modifications, formation lithology and permeability evaluation, preparation and review of cement plans, hydrologic testing plans, water storage handling plans, permit coordination with Florida Department of Environmental Protection (FDEP), preparation of casing seat and confinement justification/request letters to FDEP, Evaluation of construction methods, and preparation of client monthly progress reports and FDEP weekly construction summaries. The construction of the first injection well system started in May 2010 and completed in September 2011. The second well system is expected to be completed in July 2013.
Construction method reviews
Bench-scale testing evaluation
First deep injection well below 4,400 feet below land surface (bls) in the state of Florida.
Precipitation and plugging potential evaluation study.