% % ^ EPA Region 7 TMDL Review TMDLID: KS-LA-12-282_3 Document Name: LITTLE ARKANSAS RIVER State: KS Basin(s): HUC(s): Water body(ies): Tributary(ies): MIDDLE ARKANSAS - LITTLE ARKANSAS 11030012 BLACK KETTLE CR, BULL CR, CHISHOLM CR, CHISHOLM CR, MIDDLE FORK, DRY CR, DRY TURKEY CR, EMMA CR, GOOSEBERRY CR, HORSE CR, JESTER CR, JESTER CR, W FK, KISIWA CR, LITTLE ARKANSAS R, LONE TREE CR, RUNNING TURKEY CR, SALT CR, SAND CR, TURKEY CR BEAVER CREEK (26), BLAZE FORK CREEK, EAST FORK JESTER CREEK, EMMA CREEK (6), MIDDLE EMMA CREEK (7), MUD CREEK (16), NORTH BRANCH KISIWA CREEK, OPOSSUM CREEK, SAND CREEK (4), WEST EMMA CREEK (8), WEST FORK CHISHOLM CREEK, WEST FORK JESTER CREEK, WOLF CREEK Pollutant(s): TOTAL SUSPENDED SOLIDS (TSS) Submittal Date: 9/27/2013 Approved: Yes Submittal Letter and Total Maximum Daily Load Revisions The state submittal letter indicates final TMDL(s) for specific pollutant(s) and water(s) were adopted by the state, and submitted to the EPA for approval under Section 303(d) of the Clean Water Act [40 CFR § 130.7(c)(1)], Include date submitted letter was received by the EPA, date of receipt of any revisions and the date of original approval if submittal is a revised TMDL document. The TMDL document for total suspended solids was submitted by the Kansas Department of Health and Enviromnent as an email attachment on September 27, 2013. After comments from the U. S. Enviromnental Protection Agency, modified final submittals were received as email attachments on January 6, April 1 and May 29,2014. Water Quality Standards Attainment The targeted pollutant is validated and identified through assessment and data. The water body's loading capacity for the applicable pollutant is identified and the rationale for the method used to establish the cause-and- effect relationship between the numeric target and the identified pollutant sources is described. The TMDL(s) and associated allocations are set at levels adequate to result in attainment of applicable water quality standards [40 CFR § 130.7(c)(1)]. A statement that the IVOS will be attained is made. Expected aquatic life support is impaired by total suspended solids on the Little Arkansas River, segments 1, 3, 5, 9, 10 and 14; Turkey Creek, segments 11 and 12; Black Kettle Creek segment 368; Kisiwa Creek segment 15 and their tributaries as monitored by stations SC246, SC282, SC533, SC703, SC705 and SC728. Siltation is a leading cause for diminishing aquatic life in stream systems, and TSS is an important indicator typically linked to erosion, siltation and nutrient transport. The median TSS value for the six stations are above the median value of 50 milligrams per liter which suggests the river is not likely to support a rich diversity of aquatic life. The KDHE analyzed 15 years of total suspended solids data and associated biological monitoring data. A strong threshold relationship existed at 50 mg/L median TSS, above which streams are unlikely to support a rich diversity of aquatic life. Each of these stations were monitored bimonthly or quarterly. For rotational stations SC533, SC534, SC535, SC703 and SC705, they were monitored every four years between 1990 and 2010. For permanent stations SC246 and SC282, they were sampled every year from 1990 to 2011. The Little Arkansas Watershed Restoration and ------- Protection Strategy group has also funded sampling by Kansas State University throughout the watershed from 2008 to 2010. Sampling data for the sampling sites were categorized into three defined seasons: spring from April to June, summer-fall from July to October and winter from November to March. Median values were used to determine long term conditions because of the large variability in ambient total suspended solids concentrations. Total suspended solids concentrations were generally highest during the spring season for stations on the Little Arkansas River and highest during the summer-fall season for tributary stations, likely reflecting thunderstorm events sampled in the summer. The highest TSS seasonal average for stations on the Little Arkansas River was 832 mg/L TSS at SC246 with 11 to 25 percent flow exceedance during summer-fall, and the lowest TSS average was 17 mg/L TSS at SC728 at 76 to 100 percent flow exceedance during winter. The KDHE then compared TSS samples from SC282 for years with full biological support for both the Macroinvertebrate Biotic Index and the percent of Ephemeroptera, Plecoptera and Trichoptera, and years that did not achieve full support for both indexes. During years when the biology indices were fully supporting aquatic life, the TSS values were much lower during normal flow conditions of 26 to 75 percent flow exeedance, slightly lower during high flow conditions of 0 to 25 percent flow exceedance and showed relatively little difference during low flows of 76 to 100 percent flow exceedance. Because the KDHE had site specific, paired biological and TSS monitoring data at SC282, a load duration curve for the TSS target was established using sampling years where there was full biological support. A cubic regression between the TSS samples collected during the years of full support and the respective percent of flow exceedance for these samples was computed to define the TSS target concentrations to meet the narrative suspended solids water quality criteria within the watershed. The resulting concentrations calculated through the cubic regression were modified by averaging the calculated concentrations for the normal and low flow conditions since there was little variation during these flow conditions. The established TSS concentration targets apply to each station within the watershed and were used to compute load targets within the watershed. The cubic regression approach has a 41 mg/L median TSS value which is more conservative than the listing value of 50 mg/L TSS. The resulting loading capacity at 50 percent flow exceedance with a TSS target concentration of 36 mg/L TSS, derived from the cubic regression, at SC246 is 1.750 tons per day TSS, at SC282 is 6.512 tons/day TSS and at SC728 is 6.890 tons/day TSS. The EPA agrees that the TMDLs are set at a level adequate to result in attainment of applicable water quality standards. Designated Use(s), Applicable Water Quality Standard(s) and Numeric Target(s) The submittal describes applicable water quality standards, including beneficial uses, applicable numeric and/or narrative criteria, and a numeric target. If the TMDL(s) is based on a target other than a numeric water quality criterion, then a numeric expression, site specific ifpossible, was developed from a narrative criterion and a description of the process used to derive the target is included in the submittal. All streams in the watershed are designated for expected aquatic life support. Expected aquatic life support is listed as impaired by total suspended solids for the following water body segments. Designated Uses: • Little Arkansas River (1, 14) and Dry Turkey Creek (13) - primary contact recreation B, drinking water supply, food procurement, groundwater recharge, industrial, irrigation and livestock • Little Arkansas River (3, 5, 9, 10) and Jester Creek (2) - primary contact recreation C, drinking water supply, food procurement, groundwater recharge, industrial, irrigation and livestock • Chisholm Creek (1693) - secondary contact recreation a, drinking water supply, food procurement, groundwater recharge, industrial, irrigation and livestock • Kisiwa Creek (15) - secondary contact recreation b, drinking water supply, food procurement, groundwater recharge, industrial, irrigation and livestock • Black Kettle Creek (368) - primary contact recreation B, drinking water supply, groundwater recharge, industrial, irrigation and livestock • Bull Creek (24) - primary contact recreation C, drinking water supply, groundwater recharge, industrial, irrigation and livestock • Running Turkey (25) and Horse Creek (19) - secondary contact recreation b, drinking water supply, ------- groundwater recharge, industrial, irrigation and livestock • Lone Tree Creek (20) - secondary contact recreation b, food procurement, groundwater recharge, irrigation and livestock • Sand Creek (23) and Turkey Creek (11) - primary contact recreation C, groundwater recharge, irrigation and livestock • Middle Fork Chisholm Creek (819) - secondary contact recreation b, food procurement, irrigation and livestock • Dry Creek (22) - secondary contact recreation b, groundwater recharge and livestock • Gooseberry Creek (17) - secondary contact recreation b, food procurement and industrial • Turkey Creek (12) - secondary contact recreation b, irrigation and livestock • West Fork Jester Creek (18) - primary contact recreation C, food procurement and livestock • Salt Creek (21) - secondary contact recreation b There are no existing numeric sediment criteria in Kansas. Instead, the KDHE identified the applicable water quality criteria established for protection of beneficial uses as follows: "Suspended Solids: Suspended solids added to surface waters by artificial sources shall not interfere with the behavior, reproduction, physical habitat, or other factors related to the survival and propagation of aquatic or semiaquatic life or terrestrial wildlife. In the application of this provision, suspended solids associated with discharges of pre-sedimentation sludge from water treatment facilities shall be deemed noninjurious to aquatic and semiaquatic life and terrestrial wildlife, if these discharges comply fully with the requirement of paragraphs (b)(6) and (8) and paragraph (c)(2)(D) of this regulation. (K. A.R. 28- 16-28e(c)(2)(B))." "Surface waters shall be free, at all time, from the harmful effects of substances that originate from artificial sources of pollution and that produce any public health hazard, nuisance condition, or impairment of a designated use. (K.A.R. 28-16-28e(b)(l))." "Hazardous materials derived from artificial sources, including toxic substances, radioactive isotopes, and infectious microorganisms derived directly or indirectly from point or nonpoint sources, shall not occur in surface waters at concentrations or in combinations that jeopardize the public health or the survival or well-being of livestock, domestic animals, terrestrial wildlife, or aquatic or semiaquatic life. (K.A.R. 28-16-28e(b)(2))." "Surface waters shall be free of all discarded solid materials, including trash, garbage, rubbish, offal, grass clippings, discarded building or construction materials, car bodies, tires, wire, and other unwanted or discarded materials. The placement of stone and concrete rubble for bank stabilization shall be acceptable to the department, if all other required permits are obtained before placement. (K.A.R. 28-16- 28e(b)(3))." "Surface waters shall be free of floating debris, scum, foam, froth, and other floating materials directly or indirectly attributable to artificial sources of pollution. (K.A.R. 28-16-28e(b)(4))." "Oil and grease from artificial sources shall not cause any visible film or sheen to form upon the surface of the water or upon submerged substrate or adjoining shorelines, nor shall these materials cause a sludge or emulsion to be deposited beneath the surface of the water or upon the adjoining shorelines. (K.A.R. 28-16-28e(b)(5))." "Surface waters shall be free of deposits of sludge or fine solids attributable to artificial sources of pollution. (K.A.R. 28-16-28e(b)(6))." "Taste-producing and odor-producing substances or artificial origin shall not occur in surface waters at concentrations that interfere with the production of potable water by conventional water treatment processes, that impart an unpalatable flavor to edible aquatic or semiaquatic life or terrestrial wildlife, or that result in noticeable odors in the vicinity of surface waters. (K.A.R. 28-16-28e(b)(7))." "The natural appearance of surface waters shall not be altered by the addition of color-producing or turbidity-producing substance of artificial origin. (K.A.R. 28-16-28e(b)(8))." ------- "Conditions of acute toxicity shall not occur in classified surface waters outside the zones of initial dilution, nor shall conditions of chronic toxicity occur in classified surface waters outside of mixing zones. (K.A.R. 28-16-28e(c)(2)(D)(i))." "If a discharge contains a toxic substance that lacks any published criteria for the aquatic life support use, or if a discharge contains a mixture of toxic substance capable of additive or synergistic interactions, bio assessment methods and procedures shall be specified by the department to establish whole-effluent toxicity limitations that are consistent with paragraph (c)(2)(D)(i) of this regulation. (K.A.R. 28- 16-28e(c)(2)(D)(iii)." The KDHE used site specific, paired biological and TSS monitoring data at SC282 to develop a load duration curve for the TSS target using sampling years where there was full biological support. A cubic regression between the TSS samples collected during the years of full support and the respective percent of flow exceedance for these samples was computed to define the TSS target concentrations to meet the narrative total suspended solids water quality criteria within the watershed. As such, the TMDL endpoint varies with flow. For example, the resulting TSS target concentration is 36 milligrams per liter at the 50 percent flow exceedance. All designated uses for all segments will be maintained or achieved with these TMDLs. Pollutant(s) of Concern A statement that the relationship is either directly related to a numeric water quality standard, or established using surrogates and translations to a narrative WQS is included. An explanation and analytical basis for expressing the TMDL(s) through surrogate measures, or by translating a narrative water quality standard to a numeric target is provided (e.g., parameters such as percent fines and turbidity for sediment impairments, or chlorophyll-a and phosphorus loadings for excess algae). For each identified pollutant, the submittal describes analytical basis for conclusions, allocations and a margin of safety that do not exceed the loading capacity. If the submittal is a revised TMDL document, there are refined relationships linking the load to water quality standard attainment. If there is an increase in the TMDL(s), there is a refined relationship specified to validate that increase (either load allocation or wasteload allocation). This section will compare and validate the change in targeted load between the versions. There is an established link between the narrative water quality standard for suspended solids and the targeted load duration curve of total suspended solids. There are no existing numeric sediment criteria currently in Kansas. The KDHE established this link by comparing TSS samples from SC282 for years with full biological support for both the Macroinvertebrate Biotic Index and the percent of Ephemeroptera, Plecoptera and Trichoptera, and years that did not achieve full support for both indices. During years when the biology indices were fully supporting aquatic life, the TSS values were much lower during normal flow conditions of 26 to 75 percent flow exeedance, slightly lower during high flow conditions of 0 to 25 percent flow exceedance and showed relatively little difference during low flows of 76 to 100 percent flow exceedance. Because the KDHE had site specific, paired biological and TSS monitoring data at SC282, they established a load duration curve for the TSS target using sampling years where there was full biological support. A cubic regression between the TSS samples collected during the years of full support and the respective percent of flow exceedance for these samples was computed to define the TSS target concentrations to meet the narrative suspended solids water quality criteria within the watershed. The resulting concentrations calculated through the cubic regression were modified by averaging the calculated concentrations for the normal and low flow conditions since there was little variation during these flow conditions. The established TSS concentration targets apply to each station within the watershed and were used to compute load targets within the watershed. Source Analysis Important assumptions made in developing the TMDL document, such as assumed distribution of land use in the watershed, population characteristics, wildlife resources and other relevant information affecting the characterization of the pollutant of concern and its allocation to sources, are described. Point, nonpoint and background sources ofpollutants of concern are described, including magnitude and location of the sources. The submittal demonstrates all significant sources have been considered. If this is a revised TMDL document any new sources or removed sources will be specified and explained. In the absence of a national pollutant discharge elimination system permit, the discharges associated with sources were applied to the load allocation, as opposed to the wasteload allocation for purposes of this TMDL document. ------- The decision to allocate these sources to the LA does not reflect any determination by the EPA as to whether these discharges are, in fact, unpermitted point source discharges within this watershed. In addition, by establishing these TMDL(s) with some sources treated as LAs, the EPA is not determining that these discharges are exempt from NPDES permitting requirements. If sources of the allocated pollutant in this TMDL document are found to be, or become, NPDES-regulated discharges, their loads must be considered as part of the calculated sum of the WLAs in this TMDL document. Any WLA in addition to that allocated here is not available. The TMDL covers the watershed from monitoring station SC728 in Wichita to the headwaters covering an area about 1,422 square miles in seven counties. Point Sources: There are 64 National Pollutant Discharge Elimination System permitted facilities within the watershed. Of those that discharge, there are 15 industrial facilities, 17 municipal facilities and 5 are municipal separate storm sewer system permits. Of those that do not discharge, there are 21 non-overflowing facilities and 6 facilities that discharge to permitted municipal wastewater treatment plants. All permitted facilities are listed in Appendix A of the TMDL document. Discharging industrial facilities include the AGCO Corporation (KS0080951) which discharges treated wastewater, the NCRA Refinery - McPherson (KS0000337) and Westar Energy - Hutchinson Energy Center (KS0079723) which are generally discharging below their NPDES permit limits. The BNSF Railway Corporation - Newton (KS0001082) facility has occasional discharges from storm water overflow although the permit has no design flow or total suspended solid limits. The Wichita Aquifer Storage and Recovery Phase I and II Treatment plants (KS0099392 and KS0099694) are not yet operational but will monitor TSS discharges. The facilities will return sediment to the Little Arkansas River that was removed during the treatment process. The remaining 10 facilities either do not have a design flow or any reported discharge. Details are given in the TMDL document in Table 10. Discharging municipal facilities include nine lagoon systems for the cities of Burrton, Galva, Geneseo, Goessel, Inman, Little River, Moundridge, Walton and Windom with TSS limits of 120 milligrams per liter weekly average and 80 mg/L monthly average. According to reports, these systems do not discharge consistently. There are also 8 mechanical plants for the cities of Buhler, Halstead, Hesston, McPherson, Newton, Sedgwick, Valley Center and Chisholm Creek Utility Authority with TSS limits of 45 mg/L weekly average and 30 mg/L monthly average. All facilities discharge below their limits with the exception of the city of Goessel. Because many of these facilities likely only discharge during wetter conditions or have small and inconsistent discharge volumes, it is not anticipated they are significant contributors to TSS loading. Details are given in the TMDL document in Table 11. There are five MS4 permits for the cities of Kechi, McPherson, Newton, Valley Center and Park City. The permits expired in 2009 but are still in effect until new MS4 permits are issued. The old permits require six minimum controls to be implemented. The new permits will require implementation of at least one best management practice to address TSS within two years with subsequent monitoring to assess relative impact by MS4 areas. Details are given in the TMDL document in Table 11. The remaining 21 non-overflowing facilities are prohibited from discharging but may do so during extreme precipitation or flooding events. It is not anticipated that these events would occur on a frequency or duration that would significantly contribute to TSS impairment. Details are given in the TMDL document in Appendix A. There are also 130 certified, permitted or registered animal feeding operations within the TMDL watershed which are listed in Appendix C of the TMDL document with their Kansas permit number. Five facilities have federal NPDES permits: KS0097900 laying hens, KS0085863 beef, KS0098680 swine, KS0098248 beef and KS0094331 swine. All of these livestock facilities have waste management systems designed to minimize runoff entering their operations and detain runoff emanating from their facilities. They are designed to retain a 25-year, 24-hour rainfall/runoff event as well as an anticipated two weeks of normal wastewater from their operations. Properly operating permitted facilities are unlikely to cause significant TSS loading; though extensive loading may occur if any of these facilities were in violation and discharged. While there are potentially 234,854 animal units in the watershed, the actual number at feedlot operations is typically less. Any CAFO that does not obtain an NPDES permit must operate as a no discharge facility. Any discharge from an unpermitted CAFO is a violation of Section 301. It is EPA's position that all CAFOs should obtain an NPDES permit because it provides clarity of compliance requirements and authorization to discharge when the discharges are ------- the result of large precipitation events (e.g., in excess of 25-year and 24-hour frequency/duration) or are from a man-made conveyance. Permitted CAFOs identified in this TMDL are part of the assigned WLA. Animal feeding operations and unpermitted CAFOs are considered under the LA because there is currently not enough detailed information to know whether these facilities are required to obtain NPDES permits. This TMDL does not reflect a determination by EPA that such facility does not meet the definition of a CAFO nor that the facility does not need to obtain a permit. To the contrary, a CAFO that discharges has a duty to obtain a permit. If it is determined that any such operation is a CAFO that discharge any future WLA assigned to the facility must not result in an exceedance of the sum of the WLAs in these TMDLs, as approved. Nonpoint Sources: There are various nonpoint sources that could have significant TSS loadings within the watershed. First, land use is dominated by cropland at 64 percent. Row crop production in close proximity to the streams within the watershed can contribute total suspended solids to the surface water via overland flow. Grassland land use is 24 percent with about 326,000 head of cattle in the seven counties. There are larger and fewer farms in Ellsworth, Rice and Marion counties when compared to McPherson, Reno, Harvey and Sedgwick counties. Reno county has the highest number of farmland acres and cattle. Non-permitted grazing livestock should not contribute to the TSS loading if they are managed properly, however they could contribute to the TSS loading within the watershed if they overgraze and denude pasture or riparian buffers or have access to streams. Remaining land use includes urban areas of 8 percent, forested of 3 percent, wetlands of 1 percent and open water of 1 percent. Urban areas include residential, commercial and industrial uses as well as open space like roads and lawns. The population within the watershed is around 115,401 people and increasing with the largest increases in the cities within Harvey and Sedgwick counties. About 58,400 people resided within the cities within the watershed boundary in 2000; a large portion of the remaining population was within the Hutchinson and Wichita areas. This results in a general population density of 81 people per square mile. The KDHE assumes that households outside of municipalities with municipal wastewater treatment facilities use on-site septic systems. They estimated that given the number of people, there are about 4,285 septic systems within the watershed with an anticipated failure rate of 0.93 percent. Failing septic systems likely have a negligible impact on TSS loadings because of the few numbers and an unlikely sufficient density to contribute to the TSS impairment. About 55 percent of the watershed also has a permeability value less than 1.14 inches per hour which contributes to runoff during very low rainfall intensity events. The majority of the nonpoint source sediment runoff will be contributed to large areas throughout the watershed that are not within the river alluvium along the Little Arkansas River. The highest permeable areas of 1.73 inches/hour tend to align with the grassland areas. Therefore, sediment runoff is predominantly associated with cropland acreage within the watershed. Background: Extreme precipitation events will continue to generate soil erosion from the land, transport solids into the stream channel and contribute to the aggregation and degradation process of fluvial geomorphology. All known sources of TSS for the Little Arkansas River watershed have been listed and considered. Allocation - Loading Capacity The submittal identifies appropriate loading capacities, waste load allocations for point sources and load allocations for nonpoint sources. If no point sources are present, the WLA is stated as zero. If no nonpoint sources are present, the LA is stated as zero [40 CFR § 130.2(i)]. If this is a revised TMDL document the change in loading capacity will be documented in this section. All TMDLs must give a daily number. Establishing TMDL "daily" loads consistent with the U.S. Court of Appeals for the D.C. circuit decision in Friends of the Earth, Inc. v. EPA, et al., No. 05-5015, (April 25, 2006). Estimated long term flow conditions were calculated from the U. S. Geological Survey gaging station 07143665 data from 1990 to 2011 on the Little Arkansas River at Alta Mills which is located at the same location as SC246, and the USGS gaging station 07144200 data from 1990 to 2011 on the Little Arkansas River at Valley Center which is located at the same location as SC282. Long-term flow conditions for Turkey Creek were estimated based on the drainage area ratios between SC533 and USGS gage 07143665 on the Little Arkansas River at Alta Mills. Long-term flow conditions for Black Kettle Creek (SC705), Kisiwa Creek (SC703), Emma Creek ------- (SC534), Sand Creek (SC535) and the Little Arkansas River at Wichita (SC728) were based on the drainage area ratio between the respective tributary and USGS gage 07144200 on the Little Arkansas River at Valley Center. The KDHE used site specific, paired biological and total suspended solids monitoring data at SC282 to develop a load duration curve for the TSS target using sampling years where there was full biological support. A cubic regression between the TSS samples collected during the years of full support and the respective percent of flow exceedance for these samples was computed to define the TSS target concentrations to meet the narrative suspended solids water quality criteria within the watershed. The established TSS concentration targets apply to each station within the watershed and were used to compute load targets within the watershed. The resulting loading capacity at 50 percent flow exceedance with a TSS target concentration of 36 milligrams per liter TSS at SC246 is 1.750 tons per day TSS, at SC282 is 6.512 tons/day TSS and at SC728 is 6.890 tons/day TSS. Wasteload Allocation Comment The submittal lists individual wasteload allocations for each identified point source [40 CFR § 130.2(h)], If a WLA is not assigned it must be shown that the discharge does not cause or contribute to a water quality standard excursion, the source is contained in a general permit addressed by the TMDL, or extenuating circumstances exist which prevent assignment of individual WLA. Any such exceptions must be explained to a satisfactory degree. If a WLA of zero is assigned to any facility it must be stated as such [40 CFR § 130.2(i)]. If this is a revised TMDL document, any differences between the original TMDL(s) WLA and the revised WLA will be documented in this section. Wasteload allocations will be established for facilities that consistently discharge using their existing permit limit and design flows. Inspections and monitoring of these sites will determine the contributions made by these sources. The individual WLAs in tons per day of total suspended solids for the 17 municipal facilities are listed in Table 16 of the TMDL document. The individual WLAs for industrial facilities are listed in Table 1 below. Table 1. National Pollutant Discharge Elimination System Industrial Permittees with Individual Total Suspended Solids Wasteload Allocations in the Little Arkansas River TMDL Document. Facility Name NPDES Permit Number Design Flow (MGD)* TSS WLA (tons/day) ** AGCO Corporation KS0080951 0.40 0.03 NCRA Refinery - McPherson KS0000337 2.13 0.43 BPU - McPherson #2 KS0079758 0.33 0.02 Westar Energy - Hutchinson Energy Center KS0079723 0.48 0.03 *MGD = million gallons per day **TSS WLA = total suspended solids wasteload allocation in tons per day Individual WLAs were not assigned to the two Wichita Aquifer Storage and Recovery facilities (KS0099392 and KS0099694) since they do not currently discharge. If and when they do discharge, the WLA may be derived from the reserve WLA for the watershed. The reserve WLA is based on the maximum TSS concentrations observed in the discharge of the ASR Phase II facility of 45 milligrams per liter TSS and the total design flow for both facilities of 5.6 million gallons per day. Based on these numbers, they will be well under the established reserved WLA since they rarely operate and are limited to short durations when there is relatively high flow in the Little Arkansas River. Specific WLAs for these facilities and the reserve WLA will be refined as more monitoring and operational data become available. The Watershed Reserve WLA is 1.05 TSS tons/day. The WLA for municipal separate storm sewer system storm water permits was calculated by providing a portion of the load allocation after the NPDES WLA and margin of safety were removed. The MS4 WLA was based on the proportion of developed land in the hydrologic unit code 12 watersheds and applies at flows at and above median flow conditions at the respective stations. ------- Table 2. National Pollutant Discharge Elimination System MS4 Permittees with Individual Total Suspended Solids Wasteload Allocations in the Little Arkansas River TMDL Document as a Percent of the Load Allocation for the Respective Monitoring Station. MS4 Municipality* NPDES Permit Number Monitoring Station MS4 Allocation (Percent of TSS Load Allocation) McPherson M-LA11-SN01 SC533 3.2 % Newton M-LA13-SN01 SC535 7.5% Valley Center M-LA16-SU01 SC728 4.0% Kechi M-LA09-SU01 SC728 1.6% Park City M-LA19-SU01 SC728 6.9% *MS4 = municipal separate storm sewer system A WLA of zero was assigned to concrete batch plants, pre-treatment facilities, non-discharging facilities and confined animal feeding operations since they should have no discharge. A detailed list of these facilities and their NPDES permit numbers are listed in Appendices A and C of the TMDL document. Table 3. Total Suspended Solids Wasteload Allocations for National Pollutant Discharge Elimination System Permittees in the Little Arkansas River TMDL at the Respective Monitoring Station at the Median Flow Condition. Station Location Monitoring Station Total WLA (tons/day)* Total MS4 WLA (tons/day)** Reserve WLA (tons/day) Little Ark Alta Mills SC246 0.857 0.00 0.00 Little Ark Valley Center SC282 1.692 0.003 1.05 Little Ark Wichita SC728 1.971 0.401 1.05 *WLA = Total wasteload allocation in tons per day **MS4 = Total municipal separate storm sewer system wasteload allocation in tons per day Load Allocation Comment All nonpoint source loads, natural background and potential for future growth are included. If no nonpoint sources are identified, the load allocation must be given as zero [40 CFR § 130.2(g)]. If this is a revised TMDL document, any differences between the original TMDL(s) LA and the revised LA will be documented in this section. The load allocation is the remaining load capacity after subtracting the wasteload allocations for National Pollutant Discharge Elimination System wastewater permits, municipal separate storm sewer system storm water permits and margin of safety. It is assumed that nonpoint sources are minimal within the tributaries under extremely low flow conditions. The load allocation increases proportionally as flows increase. Excess total suspended solids loading comes predominantly from nonpoint pollution sources under normal and high flow conditions. At the 50 percent flow exceedance, the LA at SC246 is 0.718 tons per day TSS, at SC282 is 3.117 tons/day TSS and at SC728 is 2.779 tons/day TSS. Margin of Safety The submittal describes explicit and/or implicit margins of safety for each pollutant [40 CFR § 130.7(c)(1)], If the MOS is implicit, the conservative assumptions in the analysis for the MOS are described. If the MOS is explicit, the loadings set aside for the MOS are identified and a rationale for selecting the value for the MOS is provided. If this is a revised TMDL document, any differences in the MOS will be documented in this section. The margin of safety is explicit and provides some hedge against the uncertainty of daily allocated total suspended solids loading. For this TMDL document, the MOS will be 10 percent of the loading capacity. This TMDL is also conservative in that it sets specific TSS target concentrations based on flow conditions not to be exceeded which will require higher load reductions in the watershed than if a median value was used. At the 50 percent flow exceedance, the MOS at SC246 is 0.175 tons per day TSS, at SC282 is 0.651 tons/day ------- TSS and at SC728 is 0.689 tons/day TSS. Seasonal Variation and Critical Conditions The submittal describes the method for accounting for seasonal variation and critical conditions in the TMDL(s) [40 CFR § 130.7(c)(1)], Critical conditions are factors such as flow or temperature which may lead to the excursion of the WQS. If this is a revised TMDL document, any differences in conditions will be documented in this section. Seasonal variation was accounted for by using load duration curves where the TMDL is applicable at all flows under all conditions. Total suspended solid concentrations are generally highest during the spring and summer- fall seasons. Figure 7 in the TMDL document appears to indicate that the critical condition for full biological support occurs during average flow conditions from 25 to 75 percent flow exceedance with slightly less critical conditions during high flows from 0 to 25 percent flow exceedance. High and low flows are critical conditions that particularly affect aquatic life. Public Participation The submittal describes required public notice and public comment opportunities, and explains how the public comments were considered in the final TMDL(s) [40 CFR § 130.7(c)(1)(H)]. An active internet website was established at www.kdheks.gov/trod 17 to convey information to the public on the general establishment of TMDLs and specific TMDLs for the Lower Arkansas River Basin. The Lower Arkansas River Basin Advisory Committee met to discuss the TMDLs in the basin on September 12, 2012, in Halstead and on April 3, 2013, in Hutchinson. A public hearing on this TMDL document was held on September 4, 2013, in Newton to receive public comments. No comments were received from the public regarding this TMDL document. Monitoring Plan for TMDL(s) Under a Phased Approach The TMDL identifies a monitoring plan that describes the additional data to be collected to determine if the load reductions required by the TMDL lead to attainment of water quality standards, and a schedule for considering revisions to the TMDL(s) (where a phased approach is used) [40 CFR § 130.7], If this is a revised TMDL document, monitoring to support the revision will be documented in this section. Although the EPA does not approve the monitoring plan submitted by the state, the EPA acknowledges the state's efforts. The EPA understands that the state may use the monitoring plan to gauge the effectiveness of the TMDLs and determine if future revisions are necessary or appropriate to meet applicable water quality standards. The KDHE will continue bimonthly sampling every year at stations SC246, SC282 and SC728. Future stream sampling will occur bimonthly every fourth year at rotational stations SC533, SC534, SC535, SC703 and SC705 with 2014 being the next scheduled sampling year. Additionally, annual biological monitoring will continue to be conducted by the KDHE at SB282. The KDHE stated that point source and municipal separate storm sewer system total suspended solids monitoring should be done as well as supplemental biological monitoring at other locations in the watershed and by the Wichita Aquifer Storage and Recovery treatment plant downstream of their outfalls. Reasonable Assurance Reasonable assurance only applies when less stringent wasteload allocation are assigned based on the assumption that nonpoint source reductions in the load allocation will be met [40 CFR § 130.2(i)]. This section can also contain statements made by the state concerning the state's authority to control pollutant loads. States are not required under Section 303(d) of the Clean Water Act to develop TMDL implementation plans and the EPA does not approve or disapprove them. However, this TMDL document provides information regarding how point and nonpoint sources can or should be controlled to ensure implementation efforts achieve the loading reductions identified in this TMDL document. The EPA recognizes that technical guidance and support are critical to determining the feasibility of and achieving the goals outlined in this TMDL document. Therefore, the discussion of reduction efforts relating to point and nonpoint sources can be found in the implementation section of the TMDL document, and are briefly described below. The states have the authority to issue and enforce state operating permits. Inclusion of effluent limits into a state operating permit and requiring that effluent and instream monitoring be reported to the state should provide reasonable assurance that instream water quality standards will be met. Section 301(b)(1)(C) requires that point source permits have effluent limits as stringent as necessary to meet WQS. However, for wasteload allocations to serve that purpose, they must themselves be stringent enough so that (in conjunction with the water body's other loadings) they meet WQS. This generally occurs when the TMDL(s)' combined nonpoint source load allocations ------- and point source WLAs do not exceed the WQS-based loading capacity and there is reasonable assurance that the TMDL(s)' allocations can be achieved. Discussion of reduction efforts relating to nonpoint sources can be found in the implementation section of the TMDL document. The excess total suspended solid loads in the Little Arkansas River are closely associated with areas used for crop production. The largest loads typically occur during spring and summer runoff with the smallest in winter months because of low stream flow. The KDHE asserts there is a good potential that best management practices will control TSS loads and improve water quality. Due to the high frequency and magnitude of the TSS excursions within this watershed, these TMDLs will be a high priority for implementation. This watershed also lies within the Little Arkansas Subbasin which has a highest priority ranking for restoration work. The Spreadsheet Tool for Estimating Pollutant Load or STEPL was used to identify priority hydrologic unit code 12s within the watershed. Those identified are within the Turkey Creek subwatershed and above monitoring station SC246. These are mapped in the TMDL document in Figure 24. Desired implementation activities include: • implement and maintain conservation farming, • improve riparian conditions along stream systems, • reduce livestock activities within riparian areas, • install pasture management practices, • minimize road and bridge construction impacts on streams, • maintain permit limits for TSS in federal and state permits, • inspect permitted facilities and monitor wastewater discharges to assure compliance, • incorporate this TMDL into the Little Arkansas Basin WRAPS program, and • establish urban and construction storm water management practices. Implementing agencies with relevant programs include the KDHE, the Kansas Department of Agriculture - Division of Conservation and Kansas State University. The anticipated time frame to install best management practices within the top priority subwatersheds is before 2015 with follow-up implementation, including other subwatersheds, from 2016 to 2020. Targeted participants are likely the agricultural producers operating within the drainage of the priority subwatersheds. Local program managers, commodity representatives and state program staff would conduct an inventory to direct state assistance programs to the principal activities most influencing the water quality of the river and its tributaries. Implementation decisions and scheduling will be guided by planning documents prepared through the Little Arkansas Watershed Restoration and Protection Strategy and the nine-element watershed plan. The KDHE lists various authorities that may be used to direct activities in the watershed to reduce pollution. In addition, the State Water Plan annually generates $16 to 18 million and is the primary funding mechanism for implementing water quality protection and pollution reduction activities in the state through the Kansas Water Plan. The state water planning process, overseen by the Kansas Water Office, coordinates and directs programs and funding toward watershed and water resources of highest priority. Typically, the state allocates at least 50 percent of the fund to programs supporting water quality protection. This watershed and its TMDLs are located within a high priority WRAPS area and should receive support for pollution abatement practices that lower the loading of sediment and nutrients. ------- |