HELENA INDUSTRIES INC. NPDES ISSUES STORMWATER CORRECTIVE ACTION PLAN

Transcription

1 HELENA INDUSTRIES INC. NPDES ISSUES STORMWATER CORRECTIVE ACTION PLAN JULY 28, 2014

2 HELENA INDUSTRIES INC NPDES ISSUES STORMWATER CORRECTIVE ACTION PLAN Prepared for Helena Industries Inc. 101 Martin Luther King Drive Helena-West Helena, AR NPDES Permit No. AR Prepared by FTN Associates, Ltd. 3 Innwood Circle, Suite 220 Little Rock, AR FTN No. R July 28, 2014

3 EXECUTIVE SUMMARY This Stormwater Corrective Action Plan has been developed in conjunction with Consent Administrative Order, LIS No., to address compliance with the toxicity requirements of Helena Industries NPDES permit for stormwater discharges at its Helena-West Helena facility, National Pollutant Discharge Elimination System Permit No. AR The schedule included in this Plan provides a means for ADEQ to assess the progress being made on each milestone. The overall schedule for completing the corrective action is shown below in Table 1: Table 1. Proposed overall schedule. TASK ADEQ ACTION MILESTONES COMPLETION DATE Phase 1 Activities Contract with Engineer (FTN) June 30, 2014* Prepare Corrective Action Submit Corrective Action Plan July 31, 2014* Plan Initial Treatability study July 31, 2014 Prepare Progress Report Submit first Progress Report July 31, 2014 Install pilot plant July 31, 2014 Treatability study report and development of design concept by FTN Meeting with ADEQ. Review CAP and design concept Hydraulic/hydrology study by FTN Prepare NPDES permit application to include modifications Prepare State Construction Permit application including design Phase 2 Activities Approval of Corrective Action Plan (CAP) Submittal of NPDES Permit Application Submittal of State Construction Permit application August 15, 2014 August 15, 2014 October 1, 2014 November 1, 2014 or 60 days after approval of CAP (whichever is later) November 1, 2014 or 60 days after approval of CAP (whichever is later) i

4 Table 1. Proposed overall schedule (continued). TASK ADEQ ACTION MILESTONES Phase 3 Activities Permit review and approval by Issuance of State ADEQ Construction Permit NPDES Permit review and Approval of permit approval by ADEQ modifications Complete construction of facilities Initiate operation of new system COMPLETION DATE January 1, 2015 March 1, 2015 *completed Bi-monthly progress reports will be submitted to ADEQ to provide a review of April 1, 2015 or 90 days after issuance of Construction permit (whichever is later) compliance with this schedule. This schedule, including the construction and operation of the new system, is dependent on the timely approval of permits and study reports by ADEQ. The first progress report will be submitted by July 31, ii

5 TABLE OF CONTENTS EXECUTIVE SUMMARY... i 1.0 INTRODUCTION HISTORICAL COMPLIANCE EFFORTS ACTION PLAN Plan Elements Phase 1 Activities Phase 2 Activities Phase 3 Activities Phase 4 Activities PROJECT SCHEDULE...7 LIST OF TABLES Table 1 Proposed overall schedule... i Table 2 Proposed overall schedule... 7 iii

6 1.0 INTRODUCTION Consent Administrative Order No. LIS- calls for implementation of this CAP. 1.1 HISTORICAL COMPLIANCE EFFORTS HII has completed significant work over the years to comply with their NPDES permit. This permit was issued to cover stormwater discharges from the plant site. The nature of these discharges, which includes flash floods over an approximately 10.2 acre plant site drainage area in the, has made compliance a difficult problem. A study required per Part B of the NPDES Permit, was implemented between May 2010 and August The study followed the standard methodology for eliminating effluent toxicity by first attempting to identify the cause of toxicity either through a direct characterization and identification or by identifying the source(s) of the toxicity. The study approach involved three lines of evaluation: 1. Direct identification of toxicants through a direct characterization and identification process using Phase I and Phase II Toxicity Identification Evaluation (TIE) procedures (EPA 1991, EPA 1993a); 2. Sampling of selected points in the stormwater collection system to identify areas where toxicants originate; and 3. Evaluating the toxicity or potential for toxicity of chemicals and products used by the facility as part of its working process. Numerous wet weather events were sampled in an attempt to identify causes or sources of toxicity. Although the study eliminated a number of classes of toxicants from consideration, TIE testing, source evaluations, and process chemical evaluations did not identify the specific cause or source of toxicity. The two main difficulties encountered in the study were: 1. The class of toxicants (surfactants) indicated by TIE testing is a notoriously difficult group of compounds to identify or quantify analytically, and 2. Drought conditions during 2011 and 2012 limited the number of wet weather events that could be sampled. 1

7 Accordingly, no control measures, corrective action, or treatment alternatives could be proposed or evaluated as part of this prior study that would specifically eliminate toxicity at the source or provide direct treatment of the identified sources. However, the use of activated carbon as a general treatment at the outfall was identified as a method to reduce toxicity based on its generic applicability for the removal of organic compounds from wastewater. Also, subsequent testing has indicated some success in the removal of toxicity through a general cleanout of stormwater drainage conveyances. Based on these results, HII is proposing to complete corrective action measures to include: The cleanout and/or replacement of certain stormwater conveyances, and The treatment of a base flow of stormwater during low flow conditions. 2.0 ACTION PLAN FTN has prepared this CAP which includes major milestones with a schedule for items to be submitted to ADEQ. 2.1 Plan Elements HII has committed to a corrective action program that includes: Source reduction to remove accumulations of solids in the stormwater collection system, and Drainage system improvements to include pipe replacement and/or lining portions of the existing drainage pipe network to improve pipe wall and joint integrity. Providing activated carbon treatment for a base flow of runoff from the site. A plan to rehabilitate a number of the stormwater conveyances has already been initiated. Conveyances have been cleaned and video-taped. A plan for lining or replacing some segments of the storm drainage as a system has been conceptually developed. This plan has included consideration for subsequent changes that may be made with the possible addition of treatment equipment. 2

8 The inability of the TIE testing to identify specific toxic compounds creates a significant problem for evaluating the potential success of treatment. Unit operations for wastewater treatment typically can be sized and evaluated based on the removal efficiency for specific analytical parameters. However, it is more difficult to quantify the success of activated carbon treatment which must be based on the removal of toxicity. Toxicity cannot be measured quickly or accurately, and could fluctuate significantly with minor changes in sampling or analytical technique or the interactions between two or more compounds. Bench scale testing has been performed which indicates that removal of the toxicity using activated carbon is possible. A pilot-scale system is being fabricated and will be installed at the facility. This system will provide more needed information for the proper design of a full-scale system. These two initial tasks will help determine the toxicity that remains after the stormwater conveyances are cleaned out and the amount of treatment that will be needed in the final system. From this understanding, the sizing of various components of the final system can begin to be developed (i.e., receiving sump, pumping, storage, and treatment units). It is expected that an integral part of any system that is developed will include a hydrograph controlled release (HCR), that will correlate releases from the Outfall with runoff from the upstream watershed of the receiving stream. The intent of the HCR will be to control toxicity within threshold limits during storm events when it is not practicable to treat all of the runoff from the plant site. A long-term hydrologic analysis, based on historic climatological data, will be performed to evaluate the potential range of required storage over time, with particular emphasis on sequential events that result in large total quantities of rainfall. Objectives of evaluating the historical hydrology include: 1. Utilize a model that uses historical rainfall and relevant climatological data to predict runoff volumes and resulting storage effects on potential discharges; 2. Use the model to evaluate effects of withdrawals, or limitations on withdrawals, on a long-term basis; and 3. Estimate required storage volumes to provide adequate storage to reduce the potential for an untreated discharge not meeting acute toxicity thresholds. 3

9 Conceptually, the model consists of two components: a rainfall/runoff model and a water balance model. The rainfall/runoff component uses the NRCS Curve Number Method to predict runoff volume from the drainage area. Then, the water balance component uses the elevation/storage relationship of the gravity storage basin to predict the water elevation in the basin based on the predicted runoff into the basin, predicted evaporation and infiltration, and water discharged or withdrawn from the basin. All model computations are performed on an average daily basis over the historic period. Further hydrologic study will be needed to determine the ratio of flows (facility runoff flow to receiving stream flow) to be expected during various storm events. By sizing the pumping, storage, and treatment units to eliminate discharges during unfavorable mixing conditions, toxicity thresholds should not be exceeded, even though a portion of the runoff may not be treated. Under this conceptual approach, a separate outfall will be established that will only discharge treated water that will meet the toxicity criteria under critical low flow conditions. An application for renewal of the current NPDES permit must be submitted to ADEQ by November 1, It is expected that this renewal application will include a request for modification to the permit to accomplish the following: 1. Allow an HCR release for the existing stormwater Outfall based on a percentage of receiving stream flow; 2. A new Outfall to release treated stormwater; 3. An application for a construction permit to allow the physical changes needed to implement new storage, pumping, treatment and the HCR flow measurements. The timely concurrence and approval by ADEQ of the permit modification request and the State Construction Permit is essential to meeting the overall project schedule and timely implementation of this CAP. 4

10 2.2 Phase 1 Activities Phase 1 activities will include the installation of a pilot-scale treatment plant and the preparation of a design concept based on a preliminary hydrologic study and the treatability study results. Phase 1 will include timely review and approval of the CAP by ADEQ. FTN will prepare engineering design details and will fabricate the pilot scale system. The preliminary design of the pilot-scale unit includes stormwater pumping and storage, prefiltration, and an activated carbon cartridge. This unit will be trailer-mounted and can be left in service as long as deemed necessary. Following the completion of the pilot scale testing, FTN will prepare a letter report that will summarize the operation of the pilot unit including any maintenance or operational problems that were encountered. As appropriate, FTN will provide recommendations for addressing these issues in the final design of the full scale system. A further review of recent toxicity testing and storm drainage improvements will be conducted, particularly in relation to identifying contaminated or benign areas of the plant facility. To optimize the hydraulics of the system, certain unimpacted/non-industrial areas could be recommended for exclusion from the drainage of Outfall 001. The results of Phase 1 activities will be used to further refine the scope of work for Phase 2 activities. 2.3 Phase 2 Activities Phase 2 is expected to include a hydraulic/hydrology study and submittal of a permit modification request, permit renewal application and State Construction Permit application and supporting documents to ADEQ. During this phase; the sizing of pumping, storage, and treatment units will be established. The selection of plant areas to be removed from the drainage of Outfall 001 will be delineated and a justification for this change will be included in the permit application documents. These areas will continue to be covered under the General Stormwater Permit for Industrial Activity. 5

11 2.4 Phase 3 Activities Phase 3 activities will include the approval, by ADEQ, of the permit modification request and permit renewal. It will also include the construction of all improvements proposed in the State Construction Permit. 2.5 Phase 4 Activities Phase 4 will include that period of time after the effective date of the new permit and will include any required monitoring or other requirements of the new permit. 6

12 3.0 PROJECT SCHEDULE An overall project schedule proposed for this CAP is shown as Table 3.1. It is proposed that bi-monthly progress reports will be submitted to ADEQ to provide a review of compliance with this schedule. This schedule, including the construction and operation of the new system, is dependent on the timely approval of permits and study reports by ADEQ. Table 2. Proposed overall schedule. TASK ADEQ ACTION MILESTONES COMPLETION DATE Phase 1 Activities Contract with Engineer (FTN) June 30, 2014* Prepare Corrective Action Submit Corrective Action Plan July 31, 2014* Plan Initial Treatability study July 31, 2014 Prepare Progress Report Submit first Progress Report July 31, 2014 Install pilot plant July 31, 2014 Treatability study report and development of design concept by FTN Meeting with ADEQ. Review CAP and design concept Hydraulic/hydrology study by FTN Prepare NPDES permit application to include modifications Prepare State Construction Permit application including design Phase 2 Activities Approval of Corrective Action Plan (CAP) Phase 3 Activities Permit review and approval by Issuance of State ADEQ Construction Permit NPDES Permit review and Approval of permit approval by ADEQ modifications Complete construction of facilities *completed Submittal of NPDES Permit Application Submittal of State Construction Permit application Initiate operation of new system August 15, 2014 August 15, 2014 October 1, 2014 November 1, 2014 or 60 days after approval of CAP (whichever is later) November 1, 2014 or 60 days after approval of CAP (whichever is later) January 1, 2015 March 1, 2015 April 1, 2015 or 90 days after issuance of Construction permit (whichever is later) 7