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HomeMy WebLinkAboutNCS000597_Responses to Applicant Comments_20210416April 16, 2021 NCDEMLR Stormwater Program responses to Galvan Industries' comments on Draft Permit NCS000597 received April 9, 2021: 1. Galvan acknowledges and accepts the requirement to collect analytical and qualitative monitoring samples during "measurable storm events," indicating that actual discharge has occurred, as defined in Part J of the draft permit. Related to this requirement, in Section D-3, outfall monitoring shall begin at least 48 hours after the previous measurable storm event (sub -parts (a) and (d)), however, the definition states 72-hours. Galvan asks that NCDEQ clarify the required minimum frequency between measurable storm events. The 48-hour requirement in Section D-3 was an error. The requirement is 72 hours. This will be corrected in the draft permit before it is sent to public notice. 2. Galvan acknowledges that Section B-10 (Conditions for Zinc Management) and Section B-11 (Metal Removing SCMs) are new requirements for this site and will result in an updated SWPPP from the current version. This is acknowledged. Please be sure to read through the requirements and pay particular attention to the required timelines. 3. Galvan has noted the following changes to quantitative monitoring: • The previous version of NCG030000 contained the requirement for analysis of O&G using EPA Method 1664 (SGT-HEM) with a benchmark of 15 mg/L. Galvan will review average monthly oil usage onsite and implement analysis of O&G/TPH only if average usage exceeds 55 gallons per month. • The draft permit now requires analysis for chemical oxygen demand (COD). • The copper parameter code for reporting has changed from 01119 to C0665 and the benchmark has changed from 0.010mg/L to 0.2 mg/L. • The zinc parameter code for reporting has changed from 01094 to 01092, but the benchmark has not changed. • Total toxic organics (TTO) testing will no longer be required under the draft permit. When initially discussed with Zahid Khan in 2019, Galvan understood that an advantage of operating under an Individual Permit is that NCDEQ can establish site -specific benchmark criteria that consider operations at the site; however, the benchmark for the most commonly used parameter onsite (zinc) has not changed in the draft permit. Was consideration given to zinc use onsite prior to setting the zinc benchmark in the draft IP? Consideration was given to zinc use onsite prior to drafting the individual permit, which is the reason for the Conditions for Zinc Management and Metal Removing SCMs. However, all general and individual permits have the same benchmarks. The rationale for the zinc benchmark is that it is % of the Final Acute Value (FAV), which is the EPA's National Recommended Water Quality Criteria (Acute) for dissolved zinc, calculated with assumed 25 mg/I hardness, and then converted to total with EPA partition translator based on assumed 10 mg/I TSS. The benchmark April 16, 2021 can't be changed, but the permittee is encouraged to work with the Regional Office to seek Tier Relief, if applicable. Additionally, the copper benchmark was incorrectly written as 2 mg/L; it will be corrected to 0.010 mg/L prior to public notice. I apologize for the confusion. 4. Can NCDEQ please clarify the requirements for submittal of DMRs under this permit? Per Table 5, it appears that DMRs for sampling conducted between January 1, 2021 and March 30, 2021 have a submittal deadline of January 31, 2022? Table 5 will be clarified to show that all DMRs are due 30 days after receiving all results, regardless of whether paper DMRs or electronic DMRs are submitted. This table was a holdover from a template that has since been updated. Please note that the registration deadline in eDMR for individual permits was January 1, 2021. The permittee will be expected to register in eDMR as soon as possible according to the instructions on the DEMLR Stormwater Program's website here: deg.nc.gov/SW-eDMR. Additional Questions: 1. May Galvan utilize historical / previous analytical monitoring data to meet Section D-1 (Required Baseline Sampling) or does NCDEQ request a new dataset to commence with this permit? No. Galvan will need to conduct quarterly monitoring according to the individual permit starting on its effective date. 2. Prior to construction of the high-speed rail line in 2016, Galvan petitioned for and was awarded representative outfall status for Outfall #2 on the site. During construction, Galvan was concerned that earthwork and relocation of Outfall #2 approximately 50 feet east of its former location would have a negative impact on stormwater quality at the outfall, and thus, has sampled other outfalls onsite. Galvan would appreciate the opportunity to discuss with NCDEQ the potential to move back to representative outfall status at Outfall #2. James Moore with the Mooresville Regional Office will take on this topic.