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HomeMy WebLinkAboutNC0046531_Permit Modification_19990222State of North Carolina Department of Environment and Natural Resources Division of Water Quality James B. Hunt, Jr., Governor Wayne McDevitt, Secretary A. Preston Howard, Jr., P.E., Director February 22, 1999 Mr. John R. Funk Coordinator Regulatory Compliance & Training Crown Central Petroleum Corporation Post Office Box 78 Paw Creek, North Carolina 28130 Dear Mr. Funk: A�� NCDENR NORTH CAROLINA DEPARTMENT OF ENVIRONMENT AND NATURAL RESOURCES Subject: Letter to Require Effluent Turbidity Monitoring Permit No. NC0046531 Paw Creek Terminal Mecklenburg County As you are aware, the turbidity monitoring requirement was eliminated from your permit upon renewal in August 1996. Although turbidity monitoring was eliminated, total suspended solids (TSS) monitoring with a limit remains in the permit. It was the Division's contention that should monitoring data indicate TSS problems, the state has the option of enforcing the instream standard for turbidity. However, the EPA is still concerned with the removal of the turbidity monitoring requirement from several oil terminal discharge permits. The following paragraphs address that concern. During the research phase required for permit development, it was noted that the 14 permits in the Paw Creek area had vastly different requirements for solids measurements. Permits contained any combination of total suspended solids (TSS), turbidity, and settleable solids monitoring and/or limits. In an effort to provide consistency, TSS, turbidity, and settleable solids results from six oil terminals in the Paw Creek area were examined from July 1994 through September 1995. Results showed that TS S and turbidity exhibited similar trends. Both pollutants appeared to increase and decrease at the same time. In addition, for the period examined, there were no turbidity violations, although there were a few TSS violations. These data resulted in the Division questioning whether monitoring was necessary for both solids parameters. Was there an added benefit to requiring turbidity monitoring in addition to TSS monitoring? The Division concluded that turbidity was correlated with TSS results, and thus, only TSS monitoring with a limit was required. In addition, North Carolina has a water quality standard for turbidity. Therefore, although turbidity monitoring is not required in the discharge permits, the State still has the authority to enforce the instream turbidity standard. • P.O. Box 29535, Raleigh, North Carolina 27626-0535 Telephone 919-733-5083 FAX 919-733-9919 An Equal Opportunity Affirmative Action Employer 50% recycled/ 10% post -consumer paper Mr. Funk February 22, 1999 Page 2 Based on concerns regarding anti -backsliding, the EPA requested the Division re- examine the basis for the elimination of turbidity monitoring for 12 of the 14 Paw Creek oil terminals that were required to monitor for turbidity prior to the most recent permit renewal. This second examination of the data showed that there were turbidity standard violations since the last analysis at several of the oil terminals. The Division will investigate the causes of these violations to determine what steps may be necessary to control solids levels at these sites. Therefore, the Division acknowledges that its second evaluation resulted in a different outcome from the initial investigation and agrees that turbidity monitoring should be added to the discharge permits for several of the oil terminals. This letter serves as the official notice that quarterly turbidity monitoring will be required at the facility effective March 1,1999. If monitoring data show a reasonable potential to violate water quality standards, then limits will be imposed upon renewal. If you have any questions concerning this change, please contact Bethany Bolt at (919) 733-5083, extension 551. Sincerely, fA. Preston Howard, Jr., P.E. cc: Central Files Mooresville Regional Office, Water Quality Section NPDES Unit Point Source Compliance Enforcement Unit " `" 6,4./ 41_ e L e). asst /1-7', cc) 20 /0 ; o. 7id-? (4 ss 77 — kai 7'4 Co Sr k 6 .r- /0 42-JILAa_ e4 r ZAP__ 414___ a, A. Ce•q 41- a4/ror 74 S •‘. oe7 &'? etZ r Zszk/ .Jolot,d2 — 7 - /, -C 0/, „/ 9 s, 017 e _Nov, , • C-f---1--4; 17 C. _i2d.sX • 4' LA/4" &-icj LLti'C /4 Dc ---- 7 ;!.. (41. /.<-• 41•41 r if • so fece_r_ c 7C /VG /Lt.. /e-a lv 4-0( I /gate,: f,/iL 71e-a74 4.1 I • '4 , •6 _ - ;II e‘a.s-0,?‘-4/e Aq7/9,..7 4./0 7/es 6.41 .7‘r^:": 4...) • _ -e 7.7 .-•or / 0 A/e/70 b./4e 7 / 714? cs: 4re S 40 /.4 - 7e fr kc-/ 0_71- /0 . -ro 1-v1v_, /el.:tett . 4_ 4 e EA'S -57(?.4.:•f!,:?1.6 ( .v x5- - , 1 ep 0 iie„..1.... -71". 7),. elo pc:it .,-7.-4/ ______ Sr.__ _MAK- • (..-c--.... >",___ _7h 4_,...-N_______ 74.e. _e< /4....‹ 1.6,._ 4.41_4:./ f-,•-.'(/ ___/.\9?-i.of e_.____. ___________-_________________ ... ___ - NPDES # = Qw(MGD) _ _ 7Q10s (cfs)= }NC0046531 Standard = ; 11 jµg11 1. -- _ ._.._.._.._.._.._.._..0.0432 0 , nt BDL=1/20L 3 1 Actual DatarRESULTS 3 1 /WC (%) = 100.00 1 Std Dev. 20.74389834 2 Mean 7.55 _- 3 1.6 1.6 C.V. 2.745883053 4 0.5 <1.0 5 6 1.8 1.8 15.5 0.5 <1.0 Mult Factor = 7 73 73 Max. Value 73 8 9 0.5 <1.0 <1.0 Max. Pred Cw 1131.5 0.5 Allowable Cw 1 1 10 1.6 1.6 11 1.6 - 1.6 12 0.5 <1.0 L Facility Name = Crown Central Parameter = NPDES # = NC0046531 Standard = }Benzene 1.19 1.1g/1 Qw (MGD) = 0.043? 7Q10s (cfs)= 0 n BDL=1/2DL Actual Data RESULTS /WC (%) = 100.00 1 0.5 <1.0 Std Dev. 21.62180963 2 1.4� .1.4 Mean 8.07 3 0.5 <1.0 C.V. 2.678377319 4 0.5 <1.0 5 0.5 <1.0 6 4.4 4.4 Mult Factor = 14.8 7 76 76 Max. Value 76 8 0.5 <1.0 Max. Pred Cw 1124.8 9 0.5 <1.0 Allowable Cw 1.19 10 2 2 11 2 2 12 0.5 <1.0