Florida Department of

Memorandum Environmental Protection

TO: Hazardous Waste Cleanup SectionContractors

FROM: Brent Hartsfield, P.E.

DATE: December 28, 2000

SUBJECT: Effluent Disposal Via Injection Well

This guidance applies to underground injection when it is used as a method for thedisposal of effluent from a groundwater treatment system during the remediation of a state-funded hazardous waste site, including drycleaner sites, managed by the Section. Thismemorandum replaces the previous memorandum of February 24, 1997, titled “Injection Wells”.The procedures outlined in this memorandum are adapted from the June 8, 2000 guideline(BPSS-8) issued by the Bureau of Petroleum Storage Systems.

1. Definition: Chapter 62-528, Florida Administrative Code (F.A.C.), defines an injectionwell as an underground disposal device whose depth is greater than the dimension ofwidth or length. Under this definition, infiltration galleries are not considered to beinjection wells and are not subject to these requirements. However, there is norequirement that a disposal well must operate under pressure to be considered aninjection well. Gravity flow disposal wells are considered to be injection wells.

2. History: On August 9, 1989 the Department of Environmental Protection’s Division ofWater Facilities (now known as the Division of Water Resource Management) issuedProgram Guidance Policy Memorandum No. UIC-89-01, which set forth requirements forthe underground injection of treated groundwater via Class V injection wells atremediation sites. The essence of this policy document has not changed since 1989. It isstill in effect but its references to Chapter 17 of the Florida Administrative Code are nowobsolete, since that chapter has been redesignated as Chapter 62. Also, the administrativeinstruments that it cites for relief from state and federal injection regulations havebecome somewhat outmoded. A water quality criteria exemption was cited as arequirement for the exceedance of a state water quality standard, and an aquiferexemption for the exceedance of a federal primary drinking water standard. Theseinstruments were seldom used -- if ever -- and have been largely abandoned in favor ofvariances.

3. Disclaimer: Nothing in this guideline or the original August 9, 1989 policy provides anexemption from the need to contact the appropriate Water Management District Officeand satisfy appropriate design and permit requirements in regard to disposal of effluentfrom a groundwater treatment system via injection.

MemorandumDecember 28, 2000Page 2

4. Permits: An enforceable Remedial Action Plan (RAP) Approval Order, or otherenforceable mechanism, serves as the Department permit for an injection well at ahazardous waste cleanup site, provided the conditions below are satisfied in the RAPdesign and monitoring proposal. No separate UIC permit from the Department isnecessary unless these conditions are not addressed, or otherwise directed by theDepartment. The requirement that an enforceable mechanism be used to approve Class Vinjection wells associated with aquifer remediation is set forth in Rule 62-528.630(2)(c)of the July 15, 1999 issue of Chapter 62-528, F.A.C., titled “Underground InjectionControl”.

5. Treatment criteria: The injected effluent must meet the primary and secondary drinkingwater standards set forth in Chapter 62-550, Florida Administrative Code (F.A.C.), andthe minimum criteria for groundwater set forth in Chapter 62-520, F.A.C., or be ofequivalent quality to the natural unaffected background in the injection zone or any zoneinto which injected fluids will migrate. The treatment criteria of Chapters 62-550 and62-520, F.A.C., are generally reflected in the groundwater cleanup requirements ofTable I of Chapter 62-777, F.A.C., for contaminants of concern at a remediation site.These criteria are generally appropriate as effluent specifications for the design of agroundwater treatment system, with the added safeguards specified in paragraph no. 6below.

6. Discharge standards: The requirements for recovered groundwater treatment design arethe same as for an NPDES discharge. This generally necessitates activated carbonpolishing, or an equivalent secondary treatment method of ensuring discharge standardswill be continuously met, following a primary treatment process designed to achieveeffluent standards (e.g., air stripping). Alternate design techniques (e.g., primarytreatment only, with additional safety measures such as telemetry and a secondary fail-safe circuit) for demonstrating discharge standards will be continuously met are alsoacceptable for remedial designs with injection wells for effluent disposal.

7. Receiving aquifer: The injection well discharge must be to the same aquifer from whichcontaminated groundwater will be withdrawn. Discharge to a deeper zone of the sameaquifer is acceptable if a representative deep well exists or will be installed to monitor thebackground water quality of the receiving zone and the discharge effects. If theinterpretation of the lithology is in question or this condition cannot be satisfied, theappropriate Department district office must be contacted to determine whether aninjection well permit is necessary in addition to the RAP Approval Order (or RAPModification Approval Order). The monitoring plan in the RAP (or RAP Modification)must include a proposal for the deeper monitoring well(s) to be used for injection wellmonitoring.

MemorandumDecember 28, 2000Page 3

8. Avoidance of migration: The injected fluids must not cause migration of the contaminantplume into areas not previously contaminated. A hydraulic analysis must be included inthe RAP to demonstrate this condition will be met.

9. RAP approval necessary: Prior to being implemented, effluent disposal via injection wellshould be proposed in a remedial action plan (or modification to a previously approvedremedial action plan).

10. Underground Injection Control (UIC) notification: RAPs and RAP Modificationproposals must contain the necessary information for a Department site manager tocomplete the attached Exhibit A fill-in-the-blanks memorandum titled “Effluent InjectionWell(s) at a Hazardous Waste Remedial Action Site”, which must be submitted to theDivision of Water Resource Management’s Underground Injection Control (UIC)Section, along with a copy of the Department reviewer’s approval document.

BDH/jlp

Attachment: Exhibit A – Memorandum titled “Effluent Injection Well(s) at a Hazardous WasteRemedial Action Site”.

cc: Jim Crane, Technical Review SectionRichard Deuerling, UIC

EXHIBIT A

UIC Notification Memorandum

Effluent Injection Well(s) ata Hazardous Waste Remedial Action Site

TO: Richard Deuerling, Mail Station 3530Division of Water Resource ManagementBureau of Water Facilities RegulationUnderground Injection Control Section

FROM: ____________________________________________________________________________________

DATE: ____________________________

SUBJECT: Effluent Injection Well(s) at a Hazardous Waste Remedial Action Site_____________________________________________________________________________

Pursuant to Rule 62-528.630(2)(c), F.A.C, inventory information is provided below to notify youof proposed Class V, Group 4, injection well(s) to be constructed for the disposal of treatedgroundwater at a hazardous waste remediation site. The treatment system has been designed toproduce an effluent that meets the injection requirements of Chapter 62-528, F.A.C.

Site name: _____________________________Site address: _____________________________City/County: _____________________________Latitude/Longitude: _____________________________

FDEP Facility Number: _____________________________

Site owner’s name: _____________________________Site owner’s address: _____________________________

_______________________________________________________________________________________

Well contractor’s name: _____________________________ (Note 1)Well contractor’s address: _____________________________

_______________________________________________________________________________________

Note 1.If an injection well installation contractor has not yet been selected, then indicate thename and address of the project’s general remediation contractor/consultant.

Richard DeuerlingPage Two Site Name: __________________________Date: _____________________ FDEP Facility No.: ___________________

The design of the treatment system consists of the following:

Design flow rate: _______________ gpmNumber of recovery wells: ___________Design influent groundwater concentration levels (ppb):

______________ ______________ ____________________________ ______________ ____________________________ ______________ ______________

The treatment system will be designed to produce an effluent quality which meets the primaryand secondary drinking water standards set forth in Chapter 62-550, F.A.C., pursuant to theunderground injection control requirements of Chapter 62-528, F.A.C., or the groundwatercriteria set forth in Table I of Chapter 62-777, F.A.C., whichever is more stringent, for eachcontaminant as follows:

______________ ______________ ____________________________ ______________ ____________________________ ______________ ______________

Note 2. Table I of Chapter 62-777, F.A.C., will usually apply. In no case has an effluentconcentration been selected that is in excess of a primary or secondary drinking waterstandard for a regulated contaminant.

A schematic of the proposed treatment system is attached. Treatment system description:______________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

Richard DeuerlingPage Three Site Name: __________________________Date: _____________________ FDEP Facility No.: ___________________

The treated groundwater will be returned to the aquifer through the proposed injection well(s).Excerpts from the Remedial Action Plan (RAP) which describe the site lithology are attached.The following is a summary description of the affected aquifer:

Depth to groundwater: _______________Aquifer thickness: __________________Name of aquifer: ____________________

A schematic of the injection well(s) is attached. The injection well(s) has been designed asfollows:

Number of wells: ____________________Bore hole diameter: _________________Diameter of well(s) (i.e., riser pipe & screen)(inches): ____Total depth of well(s) (feet): _________________________Screened interval: _______ to _______ feet below surfaceGrouted interval: ________ to ________ feet below surfaceCasing diameter, if applicable (inches): _________________Cased depth, if applic.: _____ to ______ feet below surfaceCasing material, if applic.: _________________

The Remedial Action Plan estimates that site rehabilitation will take _______ years. We willnotify you if there are any modifications to the remediation strategy which will affect theinjection well design or the flow rate of recovered groundwater.

The proposed remediation system was approved on _____________ by a RAP approval memoor other enforceable document (copy attached). Please contact me at ____________________ ifyou require additional information.

Attachments