Rules of Department of Natural Resources Division 20—Clean Water Commission Chapter 7—Water Quality Title Page 10 CSR 20-7.010 Prevention of Pollution from Wells to Subsurface Waters of the State (Rescinded July 10, 1980) ...................................................................3 10 CSR 20-7.015 Effluent Regulations............................................................................3 10 CSR 20-7.020 Effluent Regulations (Rescinded July 10, 1980) .........................................10 10 CSR 20-7.030 Water Quality Standards (Rescinded December 11, 1977).............................10 10 CSR 20-7.031 Water Quality Standards .....................................................................10 10 CSR 20-7.050 General Methodology for Development of Impaired Waters List ...................137 MATT BLUNT (6/30/04) CODE OF STATE REGULATIONS 1 Secretary of State Chapter 7—Water Quality 10 CSR 20-7 Title 10—DEPARTMENT OF dye tracing studies, bedrock characteristics, mg/l and a weekly average of sixty-five (65) NATURAL RESOURCES geographical data and other geological fac- mg/l; Division 20—Clean Water Commission tors. Only discharges which in the opinion of B. If the facility is a trickling filter Chapter 7—Water Quality the department reach the losing section and plant the BOD5 and NFRs shall be equal to or which occur within two (2) miles upstream of less than a monthly average of forty-five (45) 10 CSR 20-7.010 Prevention of Pollution the losing section of the stream shall be con- mg/l and a weekly average of sixty-five (65) from Wells to Subsurface Waters of the sidered releases to a losing stream. A list of mg/l; State known losing streams is available from the C. Where the use of effluent limita- (Rescinded July 10, 1980) Water Pollution Control Program. Other tions set forward in this section is known or streams may be determined to be losing by expected to produce an effluent that will AUTHORITY: section 204.026, RSMo 1978. the Division of Geology and Land Survey; endanger or violate water quality, the depart- Original rule filed June 19, 1974, effective 4. Metropolitan no-discharge streams. ment will set specific effluent limitations for June 29, 1974. Amended: Filed April 1, These streams and the limitations on dis- individual dischargers to protect the water 1975, effective April 11, 1975. Rescinded: charging to them are listed in the commis- quality of the receiving streams. When a Filed Oct. 12, 1979, effective July 10, 1980. sion’s Water Quality Standards 10 CSR 20- waste load allocation or a total maximum 7.031. This rule shall in no way change, daily load study is conducted for a stream or amend or be construed to allow a violation of stream segment, all permits for discharges in 10 CSR 20-7.015 Effluent Regulations the existing or future water quality standards; the study area shall be modified to reflect the 5. Special streams—wild and scenic limits established in the study; PURPOSE: This rule sets forth the limits for rivers, Ozark National Scenic Riverways and D. The department may require more various pollutants which are discharged to Outstanding State Resource Waters; stringent limitations than authorized in sub- the various waters of the state. The two pre- 6. Subsurface waters in aquifers; and sections (3)(A) and (B) under the following vious rules 10 CSR 20-6.050 and 10 CSR 20- 7. All other waters except as noted in conditions: 7.010 have been rescinded and this rule com- paragraphs (1)(A)1.–6. of this rule. (I) If the facility is an existing facil- bines certain aspects of both rules and modi- (B) The effluent limitation for each catego- ity, the department may set the BOD and fies the format of the effluent regulations. 5 ry is listed separately in sections (2)–(8). In NFR limits based upon an analysis of the past This rule also complies with the latest addition to the limitations identified under performance, rounded up to the next five (5) changes to the Federal Clean Water Act, P.L. each specific designation, the general condi- mg/l range; and 97-117 (1981). tions contained in section (9) apply to all dis- (II) If the facility is a new facility, (1) Designations of Waters of the State. charges. the department may set the BOD5 and NFR (A) For the purpose of this rule, the waters limits based upon the design capabilities of (2) Effluent Limitations for the Missouri and of the state are divided into the following cat- the plant considering geographical and cli- Mississippi Rivers. egories: matic conditions; (A) The following limitations represent the 1. The Missouri and Mississippi Rivers; (a) A design capability study has maximum amount of pollutants which may be 2. Lakes and reservoirs, including natu- been conducted for new lagoon systems. The discharged from any point source, water con- ral lakes and any impoundments created by study reflects that the effluent limitations taminant source or wastewater treatment the construction of a dam across any water- should be BOD5 equal to or less than a facility. way or watershed. An impoundment designed monthly average of forty-five (45) mg/l, a (B) Discharges from wastewater treatment for or used as a disposal site for tailings or weekly average of sixty-five (65) mg/l, NFRs facilities which receive primarily domestic sediment from a mine or mill shall be con- equal to or less than a monthly average of sidered a wastewater treatment device and not waste or from publicly-owned treatment seventy (70) mg/l and a weekly average of a lake or reservoir. Releases to lakes and works (POTWs) shall undergo treatment suf- one hundred ten (110) mg/l. reservoirs include discharges into streams ficient to conform to the following limita- (b) A design capability study has one-half (1/2) stream mile (.80 km) before tions: been conducted for new trickling filter sys- the stream enters the lake as measured to its 1. Biochemical Oxygen Demand5 tems and the study reflects that the effluent (BOD ) and nonfilterable residues (NFRs) normal full pool; 5 limitations should be BOD5 and NFRs equal 3. A losing stream is a stream which dis- equal to or less than a monthly average of to or less than a monthly average of forty (40) tributes thirty percent (30%) or more of its thirty milligrams per liter (30 mg/l) and a mg/l and a weekly average of sixty (60) mg/l; flow through natural processes such as weekly average of forty-five milligrams per and through permeable geologic materials into a liter (45 mg/l); E. If the facility is a POTW wastewa- bedrock aquifer within two (2) miles’ flow 2. pH shall be maintained in the range ter treatment facility providing at least prima- distance downstream of an existing or pro- from six to nine (6–9) standard units; ry treatment during a precipitation event and posed discharge. Flow measurements to 3. Exceptions to paragraphs (2)(B)1. discharges on a noncontinuous basis, the dis- determine percentage of water loss must be and 2. are as follows: charge may be allowed provided that: corrected to approximate the seven (7)-day A. If the facility is a wastewater (I) BOD5 and NFRs equal to or less Q10 stream flow. If a stream bed or drainage lagoon, the NFRs shall be equal to or less than a weekly average of forty-five (45) mg/l. way has an intermittent flow or a flow insuf- than a monthly average of eighty (80) mg/l The NFR (total suspended solids) limit may ficient to measure in accordance with this and a weekly average of one hundred twenty be higher than forty-five (45) mg/l for com- rule, it may be determined to be a losing (120) mg/l and the pH shall be maintained bined sewer overflow treatment devices when stream on the basis of channel development, above 6.0, and the BOD5 shall be equal to or organic solids are demonstrated to be an valley configuration, vegetation development, less than a monthly average of forty-five (45) insignificant fraction of total inorganic storm Rebecca McDowell Cook (8/31/00) CODE OF STATE REGULATIONS 3 Secretary of State 10 CSR 20-7—Natural Resources Division 20—Clean Water Commission water generated solids, and the permittee can per day (gpd) of effluent, or fraction thereof, four hundred (400) fecal coliform colonies demonstrate that achieving a limit of except that— per one hundred milliliters (100 ml) and a forty-five (45) mg/l is not cost effective rela- A. Point sources that discharge less daily maximum of one thousand (1,000) fecal tive to water quality benefits. In these cases, than twenty-five thousand (25,000) gpd may coliform colonies per one hundred milliliters an alternative total suspended solids limit only be required to submit an annual report; (100 ml) from April 1 to October 31. The would be developed. B. Point sources that discharge more department may waive or relax this limitation (II) pH shall be maintained in the than one (1) million gallons per day (mgd) if the permittee can demonstrate that neither range from six to nine (6–9) standard units; will be required at a minimum to collect health nor water quality will be endangered and twenty (20) wastewater samples per year by failure to disinfect; (III) Only the wastewater in excess unless the applicant can show that the 4. Where the use of effluent limitations of the capacity of the noncontinuous waste- wastewater has a consistent quality, such as set forth in section (3) is known or expected water treatment plant hydraulic capacity may once through cooling water or mine dewater- to produce an effluent that will endanger or be discharged; ing, then the department may set less fre- violate water quality, the department may 4.