CONTACT: DEP Press Office, 850.245.2112,


The Florida Department of Environmental Protection’s (DEP) priority is always the safety of Floridians and our environment and our staff was on-site to investigate the issues at Mosaic’s New Wales facility less than 24 hours after being notified. Since Mosaic’s initial report of the Water Loss Incident at its Polk County New Wales facility on Aug. 28, DEP has maintained strict oversight of the recovery process and made frequent site visits to ensure timely and appropriate response continues in order to safeguard public health and natural resources.


Governor Scott directed DEP to expedite our investigation, which began on Aug. 29. While Mosaic has taken responsibility, our job is to ensure 100 percent safe drinking water in Florida and to protect our state’s pristine environment. As directed by the Governor, DEP is expediting all water-quality tests to ensure safe drinking water for residents. Governor Scott has also directed the Department of Health to partner with DEP in our investigation to ensure all drinking water in the area is safe. 


To keep the public informed of the latest response activities and most recent monitoring data, DEP will issue a daily update on this issue.

DEP’s Ongoing Oversight:

Department staff continues to perform frequent, targeted site visits to monitor progress and provide direction and assistance on response activities.

The department continues to communicate with Mosaic on a daily basis to receive updates on the status of the site, and the most recent monitoring results, along with a review of investigative activities in accordance with the requirements of applicable state permits and state orders.

Below is a timeline of action taken by DEP since notification of this incident:

  • Aug. 28, 2016: DEP was notified by Mosaic of a Water Loss Incident at its New Wales Facility in Polk County.

    • Mosaic reported that it immediately took steps and initiated response actions to investigate the water loss working with a third-party engineering consultant, Ardaman & Associates, Inc.

    • Mosaic also reported that it had initiated transferring process water from the impacted cell at a rate of up to 8,000 gallons per minute to a nearby, non-impacted cell to reduce additional losses.

  • Aug. 29, 2016: DEP begins its investigation and performs an initial site visit to assess the site and ensure that Mosaic was properly responding to the incident.

    • Based on this visit, DEP directed Mosaic to expedite operation of an additional onsite recovery well to ensure the process water would be captured and contained onsite (within Mosaic’s facility).

  • Aug. 29, 2016: Mosaic reported release to the State Watch Office. Report received by DEP, EPA, Division of Emergency Management and Polk County.

  • Aug. 30, 2016: Mosaic reported that its consultant performed an inspection and helicopter surveillance to assess pond and liner conditions.

  • Sept. 3, 2016: As required by DEP, Mosaic submitted an initial 7-day Report, prepared by their consultant, of the 2016 Water Loss Incident. DEP staff reviewed the report, which included findings to date, groundwater quality and a recommended monitoring plan and plan of action.

  • Sept. 6, 2016: DEP staff performed an additional site visit to review the ongoing investigation related to the stack drain system, and to inspect the condition of the impacted cell. At this time, the west cell no longer held process water, but a sinkhole opening was not visible from the dike.

  • Sept. 7, 2016: Mosaic provided an aerial photograph, taken on the afternoon of Sept. 6, that confirmed the presence of the sinkhole.

  • Sept. 7, 2016: DEP and Hillsborough County Environmental Protection Commission (EPC) reviewed the status of New Wales Water Loss Incident. DEP provided follow-up information to Hillsborough County EPC representative.

  • Sept. 7, 2016: After prior coordination and discussions with EPA, DEP provided an overview presentation to EPA Region 4 and Headquarters representatives on the sinkhole conditions, monitoring information, and the status of Mosaic response activities. DEP and EPA continued ongoing discussions.

  • Sept. 9, 2016: DEP and EPA coordinated with Mosaic to plan an onsite meeting and presentation on ongoing response activities and plans for remediating the sinkhole.

  • Sept. 10, 2016: Mosaic reported that it brought an additional recovery well online to improve the ability to contain and recover process water at the site.

  • Sept. 13, 2016: DEP staff performed a follow-up site visit to review operations of recovery wells and plans for related water management activities. Staff inspected conditions in the impacted cell and the initial work to widen a road to better accommodate future construction and remediation activities.

  • Sept. 15, 2016: DEP had a follow-up meeting with EPA to review the status of response actions.

  • Sept. 16, 2016: DEP coordinated drinking water sampling with the Department of Health in Polk County.

  • Sept. 19, 2016: DEP provided aerial photograph of site, groundwater monitoring information, and updated outreach information on the status of response activities to Hillsborough County EPC.

  • Sept. 19, 2016: Although the affected water is contained on-site, DEP, in an abundance of caution, began working with Mosaic to reach out to the nearest adjacent homeowners who may want their drinking-water wells tested.

  • Sept. 19, 2016: DEP held discussions with EPA Region 4 management in Atlanta to coordinate on response activities.

  • Sept. 20, 2016: DEP staff performed a follow-up site visit to observe site preparation for restoration and response activities. Mosaic reported that it continues to widen the gypsum crest roads to establish ease of access for equipment. Mosaic reported that site restoration work is expected to begin the week of Sept. 26.

  • Sept. 20, 2016: DEP coordinated with the Southwest Florida Water Management District on Floridan Aquifer groundwater mapping information.

  • Sept. 20, 2016: DEP and EPA held a status update call on response activities.

  • Sept. 20 and 22, 2016: DEP staff collected samples from drinking water wells from residents in the vicinity. This is an ongoing effort.

  • Sept. 20 and 21, 2016: DEP staff began independent water sampling from wells at the Mosaic facility. DEP has been reviewing water sampling data provided by Mosaic since being notified of this incident.

  • Sept. 21, 2016: DEP conducted an on-site visit to coordinate with Mosaic on the finalization of plans for the installation of four additional groundwater monitoring wells, three of which are to the west, downgradient (the direction of groundwater flow) of the sinkhole formation. These wells will provide additional monitoring coverage so Mosaic and the department can continue to ensure there is no indication of off-site impacts.

  • Sept. 21, 2016: EPA notified DEP that an EPA staff member will be reporting to the impacted site for the first time on Sept. 23, 2016. 

  • Sept. 22, 2016: DEP met with EPA at DEP’s Southwest District Office to discuss the status of response actions at the site. 

  • Sept. 22, 2016: DEP collected samples from private drinking water wells. DEP also received test results from Mosaic’s contractor for sampling of private drinking water wells occurring on Sept. 19 and 20. DEP reviewed these results and the analyses show the reported values are within normal range of background water quality data and therefore not impacted by process water. This is consistent with the monitoring of onsite groundwater wells which continues to show no offsite impact. 

  • Sept. 22, 2016: Mosaic reported it continues to widen the gypsum crest road in preparation for investigative and remedial work. Mosaic also reported it plans to use remote sensing equipment next week to characterize the sinkhole within the stack and establish a safe work area.  

  • Sept. 22, 2016: DEP approved the installation of four additional Floridan groundwater monitoring wells to provide additional assurance that the impacts from the sinkhole are captured and contained onsite. The installation of these additional wells are being expedited. 

Sinkhole Investigation:

  • DEP’s Florida Geological Survey is assisting in the department’s investigation into the formation and remediation of the sinkhole.

  • Mosaic is reporting that there have been no adverse changes or increase in the size of the sinkhole formation through Thursday, Sept. 22, 2016.

  • Mosaic is reporting that their engineering consultant continues to establish safe, stable locations for staging equipment to access the sinkhole feature so remediation activity can begin.

Groundwater Quality:

Mosaic Groundwater Monitoring Wells

The department is receiving data from Mosaic that is based on the company’s network of monitoring wells that capture water quality data within the three aquifer systems at the site -  the Surficial Aquifer, the Intermediate Aquifer and the Floridan Aquifer. By the regular testing and reported data from these wells, DEP is able to confirm no off-site migration is occurring.

Monitoring to date continues to indicate that the affected water is being successfully contained, and that there is no evidence of off-site movement or threat to off-site groundwater supplies. Daily oversight and routine groundwater monitoring will continue to ensure there are no off-site or long-term effects.


  • Specifically, as of Thursday, Sept. 22, the recovery well efforts continue to successfully capture and contain released process water from the Floridan Aquifer.

  • Groundwater data from on-site monitoring wells shows no movement of process water outside of the capture zone of the onsite recovery well.

Drinking Water

Although the affected water is currently contained on site, DEP, in an abundance of caution, is working with Mosaic to reach out to the nearest adjacent homeowners who may want their drinking-water wells tested.


Sampling began Sept. 19, 2016.


Public Water Supply Well Testing Information as of Sept. 22, 2016




Drinking Water Well Tests



Ongoing monitoring of nearby wells continues to indicate that affected water is contained to the impacted site. The nearest private drinking well is around 3 miles away from the site, and thus far in DEP’s investigation there is no indication that there is a threat to this well. Both Mosaic and DEP will continue to perform sampling, and if any indication of off-site migration is seen, affected homeowners will be immediately notified.


Mosaic reports that it has contracted with an independent, third-party contractor to take the samples, which will be sent to a third-party lab. DEP staff will be available to perform sampling alongside these contractors or independently. 


If you would like to continue to receive daily updates on the Mosaic-New Wales sinkhole,