62-610.865. Blending of Demineralization Concentrate with Reclaimed Water

(1) Within this chapter, the term “concentrate” will be used synonymously with “demineralization concentrate.” The Department shall classify demineralization concentrate as a “potable water byproduct,” and not as an “industrial wastewater.”

(2) Rule 62-610.865, F.A.C., applies to projects, for which complete permit applications which request authorization to blend concentrate with reclaimed water were received by the Department on or after August 8, 1999. Rule 62-610.865, F.A.C., also shall apply to existing projects which are being expanded or modified; however, these rule requirements shall only apply to the expanded or modified portion of the project.

(3) Demineralization concentrate may be blended with reclaimed water which will be used in reuse systems regulated under Parts II, III, IV, and VII of this chapter if all of the requirements of Rule 62-610.865, F.A.C., and the appropriate parts of this chapter are met.

(4) Permittees wishing to blend demineralization concentrate with reclaimed water are urged to proceed cautiously. Concentrate typically contains elevated concentrations of dissolved solids and inorganic constituents, which normally are not removed from the reclaimed water as it travels through the unsaturated or saturated zones beneath the Earth’s surface. As a result, the ability of a reuse or land application project to meet ground water quality criteria at the edge of the zone of discharge shall be addressed in the engineering report. Elevated concentrations of dissolved solids and salts may harm sensitive vegetation being grown on the reuse or land application site and may decrease the hydraulic capacity of reuse and land application sites, especially where reclaimed water will be used to irrigate landscape areas and edible food crops, as allowed by Part III of this chapter.

(5) Engineering report.

(a) The engineering report shall provide reasonable assurances that ground water criteria contained in Chapter 62-520, F.A.C., will be met at the edge of the zone of discharge.

(b) The engineering report shall provide reasonable assurances that the blend will not harm vegetation or crops grown on the reuse or land application sites and that the blend will not impair the ability of the site to function as intended. Salt tolerances of vegetation found in the reuse or land application system shall be evaluated.

(c) The engineering report shall evaluate the potential for salts and other constituents in the concentrate to adversely affect the infiltration/percolation capabilities of the soils in the reuse system. If the sodium adsorption ratio in the blend approaches or exceeds 15, it is recommended that sodicity hazards and impacts on soil infiltration/percolation be addressed in detail in the engineering report based on input from individuals having expertise in soils science.

(d) The engineering report shall evaluate the ability of the reuse system to protect public health.

(e) The engineering report shall examine constraints needed to ensure compliance with water quality standards and to ensure protection of environmental quality, public health, site vegetation, and the ability of reuse and land application sites to function as intended.

(f) The engineering report shall characterize the reclaimed water, concentrate, and blend.

(g) The engineering report shall include recommendations for a minimum blend ratio. This minimum blend ratio shall be justified based on the considerations described in subsection 62-610.865(5), F.A.C.

(6) Demineralization concentrate, reclaimed water, and blend quality.

(a) The applicant shall evaluate the tolerances of vegetation grown in areas to receive reclaimed water to constituents contained in the concentrate and the blend. The applicant shall evaluate potential affects of the blend on the soils to which the blend will be applied. These evaluations shall be included in an affirmative demonstration in the engineering report that the blend can be applied to the land and vegetation in an acceptable manner which will not harm the vegetation or impair the soil’s ability to accommodate the applied blend. The applicant shall establish limitations on total dissolved solids, chlorides, and sodium adsorption ratio in the blend to protect vegetation, soils, and ground water quality. The Department shall incorporate these limitations into the permit as single sample maxima limitations for the blend.

(b) The reclaimed water shall meet all requirements of the appropriate part of this chapter at a point upstream from the addition of the concentrate.

(c) The blend shall meet all requirements of the appropriate part of this chapter at the point where it is introduced into the reclaimed water conveyance or distribution system.

(d) The permit shall include a minimum blend ratio which shall be equaled or exceeded at all times.

(7) Permitting.

(a) Separate domestic wastewater and concentrate permits shall be issued, except as provided for in paragraph 62-610.865(7)(b), F.A.C. The concentrate permit holder shall be responsible for the quality of the concentrate, monitoring of the concentrate, and facilities associated with the storage and conveyance of the concentrate. The concentrate permit holder shall be responsible for hydrogen sulfide control, if needed. The domestic permit holder shall be responsible for treatment, disinfection, storage, quality, and monitoring of the reclaimed water. The domestic wastewater permit holder shall be responsible for the quality, monitoring, conveyance, and application of the blend and for all monitoring at the reuse and land application sites.

(b) A single domestic wastewater permit shall be issued if a single municipality or utility owns and operates both the domestic wastewater facilities and the water treatment facilities which generate the concentrate.

(c) In the case where separate domestic and concentrate permits are issued, the domestic wastewater permittee shall execute an agreement with the concentrate permittee to ensure acceptable project performance. The agreement shall address the quality and quantity of the concentrate, system operation, storage requirements, monitoring, sharing of information, quality control, and remedies in the event problems develop. Remedies shall include provisions for terminating the service of accepting the concentrate if problems develop.

(d) Permit fees for the domestic wastewater permit shall be based on the sum of the capacity of the domestic wastewater facility (without the introduction of the concentrate) and the maximum anticipated flow of the concentrate.

(e) Adding concentrate to the reclaimed water at an existing domestic wastewater facility and reuse system shall be considered as a modification which will subject the reuse facilities to the requirements of this chapter.

(8) Monitoring.

(a) Reclaimed water shall be monitored as required by the appropriate part of this chapter. Monitoring requirements in Chapter 62-600, F.A.C., shall apply.

(b) Flows shall be monitored continuously in two locations. The flow of the concentrate shall be monitored continuously. In addition, either the flow of the reclaimed water (before blending) or the flow of the blend shall be continuously monitored. The blend ratio shall be calculated continuously.

(c) The blend shall be monitored continuously for specific conductance. The results of this monitoring shall be used to make continuous judgments of the quality of the blend related to inorganic constituents of the blend (such as total dissolved solids and chlorides).

(d) Continuous monitoring equipment shall be equipped with an automated data logging or recording device. Continuous monitoring equipment shall be maintained according to the manufacturer’s operation and maintenance instructions. Continuous monitoring equipment shall be calibrated according to the requirements of Chapters 62-160 and 62-600, F.A.C.

(e) The blend shall be monitored as required by the appropriate part of this chapter. Monitoring requirements in Chapter 62-600, F.A.C., shall apply to the blend. Total suspended solids, fluoride, total dissolved solids, chlorides, pH, and sodium adsorption ratio shall be monitored weekly in the blend. Additional parameters to be sampled and analyzed for in the blend on a weekly basis shall be established in the permit based on characterization of the concentrate and the blend contained in the engineering report. After the first year of operation, the Department shall reduce the sampling frequency if the applicant provides an affirmative demonstration that ground water standards will be met and that site vegetation and public health will be protected.

(f) An annual scan of the parameters listed as primary and secondary drinking water standards in Chapter 62-550, F.A.C. (except for asbestos, total coliforms, color, odor and residual disinfectants), shall be for the reclaimed water and the blend.

1. Results of the scan shall be reported on Discharge Monitoring Report (DMR), DEP Form 62-620.910(10), (adopted and incorporated by reference in subsection 62-620.910(10), F.A.C., effective November 29, 1994). The DMR form shall be electronically submitted to the Department by January 28 using the DEP Business Portal at http://www-fldepportal.com/go/.

2. Approved analytical methods identified in paragraph 62-620.100(3)(j), F.A.C., shall be used for analysis. If no method is included for a parameter, methods specified in Chapter 62-550, F.A.C., shall be used.

3. After the first year, the Department shall reduce the parameters to be reported in the annual scan if the applicant provides an affirmative demonstration that ground water standards will be met and that site vegetation and public health will be protected. At a minimum, when an application for permit renewal is submitted, the full list of parameters listed as primary and secondary drinking water parameters, except for the exceptions listed in subsection 62-610.865(8)(f), F.A.C., shall be reported for the reclaimed water and the blend and submitted with the permit application.

(9) Operating protocol.

(a) In accordance with Rule 62-610.320, F.A.C., the domestic wastewater permittee shall establish an operating protocol for the blending. This operating protocol shall contain procedures designed to ensure that only acceptable quality blend water is released to the reuse system. The acceptability of the reclaimed water will be based on factors addressed in the engineering report, as described in subsection 62-610.865(5), F.A.C., such that protection of public health, environmental quality, and site vegetation will be assured. The two key parameters to be used in making continuous judgments of the acceptability of the blend are the blend ratio and the specific conductance.

(b) Reuse projects regulated under Part III of this chapter will have an additional operating protocol for operation of the domestic wastewater treatment facility, as described in Rule 62-610.463, F.A.C. The permittee may combine the two operating protocols into a single document.

(10) Demineralization concentrate storage.

(a) The demineralization concentrate permittee shall be responsible for the provision, operation, and maintenance of concentrate storage facilities.

(b) Provisions shall be made for storage of demineralization concentrate, unless a permitted alternate discharge mechanism or other approved methods are available for disposal or handling of the concentrate during periods when blending is not possible.

(c) If concentrate storage is needed to meet permit requirements, the storage pond or tank shall have a capacity equal to three days flow of concentrate at the maximum flow of the process producing the concentrate. If blending will take place after the reclaimed water system storage facilities, the concentrate storage capacity shall equal the number of days storage required to be provided in the system storage facilities for the reclaimed water.

(d) Concentrate storage systems shall be lined or sealed to prevent measurable seepage or shall be constructed of impervious materials. Requirements for lined storage ponds are contained in subsection 62-610.414(4), F.A.C.

(11) The permittee shall submit an annual summary of water quality in the reclaimed water, the concentrate, the blend, and ground water monitoring wells. Correlations between specific conductance and chloride, and total dissolved solids shall be developed and reported. The summary shall include an evaluation of any adverse effects on vegetation and ground water quality and needed corrective actions, including needed revisions to the operating protocol.

(12) Except as provided in subsection 62-610.865(13), F.A.C., blending shall be accomplished after the domestic wastewater has received all treatment and disinfection. This may be before or after system storage facilities associated with the reuse system. If blending will occur before system storage associated with the reuse system, the applicant shall provide an affirmative demonstration that the system storage facilities have sufficient capacity to meet the system storage requirements based on the combined flows of reclaimed water and the concentrate.

(13) Demineralization concentrate may be discharged into the sanitary sewerage system.

(a) All of the following conditions shall be met:

1. The resulting mixture of concentrate and domestic wastewater receives the full level of treatment required by the part of this chapter which regulates the reuse system.

2. The applicant provides an affirmative demonstration that the sewerage system and treatment facilities have sufficient capacities to accommodate the added volume of concentrate.

3. The addition of concentrate will not impair the ability of the treatment facility to meet reclaimed water limitations.

4. The resulting reclaimed water will not harm vegetation grown in the reuse system.

5. The resulting reclaimed water will not reduce the infiltration/percolation capacities of soils in the reuse system.

6. The reuse system will comply with ground water standards at the edge of the zone of discharge.

(b) If concentrate is added only to the sewerage system before treatment, the provisions in subsections 62-610.865(2) through (12), F.A.C., shall not apply.

Rulemaking Authority 403.051, 403.061, 403.087 FS. Law Implemented 403.021, 403.051, 403.061, 403.062, 403.085, 403.086, 403.087, 403.088 FS. History–New 8-8-99, Amended 8-8-21.