Compliance Disparity in MS4 Permit Requirements

Los Angeles Regional Water Quality Control Board PUBLIC FORUM: Item #7 Issues Raised by the City of Norwalk Ray Tahir TECS Environmental September 26, 2024 1

44 Good Morning Board Members I would like to expand on comments made by Norwalk Public Services Director Kau regarding Mayor Rios letter to the Chair and Vice-Chair. The MS4 data collected over a 5-year period yielded no useful results specifically no exceedances of WQS/WQOs The data was supposed to justify the 2024 Integrated Report which board staff claims resulted in the listing and de-listing of pollutants reported on the 303(d) list, based on pollutant exceedances. The data did no such thing. It only reported results from monitoring (in the receiving water) without measuring it against water quality standards/objectives. Consequently, there could not have been exceedances. (see table on next slide). So how did staff determine adding and removing pollutants from the 303(d) list? RB staff needs to answer this question. 2

44 Excerpt from MS4 Data (Excel File) CIMP Group Exceed (Y/N) Region Mon. Type Date Pollutant Criterion Unit Result WQO/WQS LSGR- WQM RB4 MS4 7/30/2019 Copper Dissolved ug/L 5.38 ? ? LSGR- WQM RB4 MS4 11/21/2019 Copper Dissolved ug/L 27.8 ? ? LSGR- WQM RB4 MS4 7/30/2019 Zinc Dissolved ug/L 2.37 ? ? LSGR- WQM RB4 MS4 11/21/2019 Zinc Dissolved ug/L 213 ? ? 3

44 Here s how the 303(d) Listing Policy Works Exceedances are plugged into the State s 303(d) Listing Policy in tables designated toxicants (metals/pesticides) and conventional pollutants. And there are separate tables for toxicants and conventional pollutants for listing and de-listing. The frequency then determines if the pollutant should be listed/de-listed. See table on next slide. But here s the problem: without exceedances there cannot be 303(d) listings, without which there can be no TMDLs. Remember: a TMDL is required when a water body is deemed impaired. No 303(d) listing, no impairment. 4

44 Example: Table Showing Exceedances Needed to List Toxicants TABLE 3.1: MINIMUM NUMBER OF MEASURED EXCEEDANCES NEEDED TO PLACE A WATER SEGMENT ON THE SECTION 303(D) LIST FOR TOXICANTS. Null Hypothesis: Actual exceedance proportion < 3 percent. Alternate Hypothesis: Actual exceedance proportion > 18 percent. The minimum effect size is 15 percent. Sample Size List if the number of exceedances equal or is greater than 2 24 25 36 37 47 48 59 60 71 72 82 83 94 95 106 107 117 118 129 2* 3 4 5 6 7 8 9 10 11 5

44 Compliance disparity between Ventura and Los Angeles County MS4s Mayor Rios pointed-out that despite the fact that Ventura and L.A. County are subject to the same MS4 permit requirements, Ventura is exempt in de-facto terms from having to comply with coercive watershed management programs that require costly infiltration controls. Instead, it is allowed to achieve compliance by implementing the Stormwater Management Program which Norwalk and other MS4s were denied. Here s the proof: According to the 2023 Annual Report for the City Camarillo which was sent to board members -- WMPs are mentioned but are only sub-sets to the Stormwater Management Program, which do not require mandatory infiltration projects. This is what Norwalk wants. WMP submittals: 6

44 LLAR, LSGR, Machado Lake Torrance, MCW; MdR (Marina Del Rey); Nearshore Watersheds-LB (Long Beach); Near Shore Ballona Creek; PVP; RHSGR; SMB J2-J3; SMB J7; ULAR; USCR; USGR; Walnut; Alamitos Bay-Los Cerritos; Ballona Creek; Beach Cities; DC; El Monte; ESGV; La Habra Heights; and LARUR2. Conspicuously absent are Ventura County WMP submittals. All of this underscores the need to meet with Norwalk to resolve these issues. 7