City Council
259 N. Wilma Avenue
Ripon, CA 95366
MEMO
To: Honorable City Council
From: James Pease, Public Works Director
Date: 09/09/2025
Subject: Trash Implementation Plan
BACKGROUND:
On April 7, 2015, the State Water Resources Control Board (State Water Board) adopted an Amendment to the Water Quality Control Plan for Ocean Waters of California to Control Trash (Ocean Plan) and the Part 1 Trash Provision of the Water Quality Control Plan for Inland Surface Waters, Enclosed Bays, and Estuaries (ISWEBE Plan). Together, they are collectively referred to as 'the Trash Amendments'. The project objective for the Trash Amendments is to provide statewide consistency for the Water Boards' regulatory approach to protect aquatic life and public health beneficial uses, and reduce environmental issues associated with trash in state waters, while focusing limited resources on high trash generating areas. The Trash Amendments accomplish this by:
Establishing a narrative water quality objective for trash, Establishing a prohibition on the discharge of trash, Providing implementation requirements for permitted storm water and other dischargers,
Setting a time schedule for compliance, and
Providing a framework for monitoring and reporting requirements.
The Trash Amendments apply to all Phase I and II permittees, under the National Pollutant Discharge Elimination System (NPDES) Municipal Separate Storm Sewer Systems (MS4) permits, which the City of Ripon is designated a Phase II permittee. The State Water Board Executive Director sent separate 13383 Orders (known as the Trash Provisions) to all traditional MS4 permittees on June 1, 2017, to comply with the Trash Amendments by December 2030.
The Trash Provisions require permittees to select a method of compliance with the trash prohibition by selecting either Track 1 or Track 2 compliance methods:
Track 1: Install, operate, and maintain Full Capture Systems for the storm drain network that capture runoff from the Priority Land Use areas in their jurisdiction. Track 2: Install, operate, and maintain any combination of Full Capture Systems, Multi-Benefit Projects, other Treatment Controls, and/or Institutional Controls within their jurisdiction.
Priority Land Use areas are identified as developed sites, facilities, or land uses within our jurisdiction from which discharges of trash are regulated by the Trash Provisions as follows:
High-density residential – ten dwelling units/acre
Industrial – involving product manufacture, storage, or distribution Commercial – places involving sale or transfer of goods or services to consumers Mixed urban – high-density residential, industrial, and/or commercial collectively Public transportation – public transit stations and stops to load or unload passengers Selecting the Track 1 compliance method for Ripon essentially means placing Full Capture Systems in all areas of the City storm drain system where Priority Land Use areas have been identified at locations prior to discharging the storm water into the Stanislaus River. The Full Capture Systems would contain a 5 millimeter screen essentially eliminating all trash from entering the Stanislaus River during normal rain events. Although most devices include an overflow mechanism for larger storm events, Public Works staff will be required to clean and maintain these devices regularly in order to eliminate potential blockages and remove trash or leaves.
Selecting the Track 2 compliance method allows the City to determine if there are areas where Full Capture Systems will not need to be installed through the development of a Trash Implementation Plan (TIP). The first step is performing a trash assessment of the Priority Land Use areas to identify a baseline trash generation rate or level for each. The goal for each of the Priority Land Use areas is to achieve a low trash generation level which is considered equivalent to the performance of a full trash capture system. Once a Priority Land Use area has been identified at a low trash generation level no further action is required and these areas will essentially be considered in compliance with the Trash Provision.
The City initially selected Track 1 back in November 2018 which includes the installation of trash capture structures at discharge locations entering into the Stanislaus River from the high priority areas, this initial capital expense was estimated in excess of $2 million. These large vault style structures would require ongoing maintenance by City staff to clear out and dispose of trash and ensure no storm flow restrictions have occurred adding another estimated expense of $80,000 annually. However, to allow for a more flexible and economically feasible compliance approach the decision was made at the December 2023 Council Meeting to switch to Track 2 and hire Stone Creek Environmental Consulting to assist with developing a TIP in order to gain compliance. The City notified the State Water Board and Central Valley Regional Water Quality Control Board (CVRWQCB) of the intent to switch to Track 2 in March 2024.
DISCUSSION/ANALYSIS:
Attached is the TIP prepared by Stone Creek Environmental Consulting with assistance from City staff. The TIP results confirm the decision to switch to Track 2 due to the low volume of trash on City streets and in our City storm drain system. The goal is to meet the equivalency of a full trash capture system as defined by the State Water Board, below is a summary of the TIP:
o 53 separate Priority Land Use areas were identified and are described in Table 1 and Figure
1. The Priority Land Use areas cover approximately 327.5 acres that discharge to the Stanislaus River.
o Two separate On-land Visual Trash Assessments (OVTAs) were performed for each of the 53 Priority Land Use areas to determine baseline trash generation levels, one during the dry weather season and one during the wet weather season. The OVTA included walking the length of each Priority Land Use area segment with staff. The trash generation levels were then rated as either low, moderate, high or very high based on the amount of trash encountered in the gutters and on sidewalks.
Low: 0-5 gallons/acre/year. Effectively no trash can be observed on a city block or the equivalent. There may be some small pieces in the area, but they are not obvious at first glance and one individual could quickly pick them up. A low trash generation level is the goal of a storm water trash control program and is considered equivalent to the performance of a full trash capture system.
Moderate: 5-10 gallons/acre/year. Predominantly free of trash except for a few pieces that are easily observed along a city block, or the equivalent. The trash could be collected by one or two individuals in a short period of time. High: 10-50 gallons/acre/year. Trash is widely/evenly distributed, and/or small accumulations are visible on the street, sidewalk, or inlets. It would take a more organized effort to remove the litter.
Very High: 50-150 gallons/acre/year. Trash is continuously seen throughout the area, with large piles and a strong impression of lack of concern for litter in that area.
There is often significant litter even along gutters that are swept. o 51 of the Priority Land Use areas were assessed at a low trash generation level which demonstrates Full Capture System equivalency and no further action is required since the goal has been met.
o 2 of the Priority Land Use areas were assessed at a moderate trash generation level, they include the Santos Avenue/Jack Tone area and Frontage Road/Milgeo Avenue area. At this time increased street sweeping and outreach to businesses will be conducted in order to reduce the amount of trash generated in these areas.
o City staff will conduct three progress OVTAs annually for both of the Priority Land Use areas that are currently assessed as a moderate trash generation level. Upon three consecutive low trash generation scores, the area would then be considered a low trash generation level. The low trash generation level would mean Full Capture System equivalency and the City would discontinue any additional progress assessments since the goal will be met.
o The City has until December 2030 to achieve this goal and progress will be assessed annually. If it is determined that low trash generation levels cannot be achieved through increased efforts at the 2 moderate rated Priority Land Use areas then the installation of Full Capture System devices at storm drain inlets may be required.
Moving forward, the TIP will be submitted to the State Water Board and implementation by City staff will begin shortly after. Additionally the State Water Board is working on a new General Permit Water Quality Order (GPWQO) for municipalities and it is anticipated to be adopted sometime in late 2026. This order will build on the current trash provisions in place, resulting in additional monitoring, reporting, and enforcement requirements.
FISCAL IMPACT:
The full cost of the Trash Provisions has yet to be realized although an estimate of expenses for each track is provided below. The cost savings benefit is clear with the decision to switch to Track 2.
Track 1:
Estimated Expenses
Capital expense for Full Capture System devices installed citywide $2,000,000 Annual maintenance cost for Full Capture System devices $80,000 Track 2:
Actual Cost to Date
Trash Implementation Plan with Stone Creek Environmental Consulting $19,500 City staff cost to assist in developing the Trash Implementation Plan $15,000 Assumed Ongoing Expenses
Land use area assessments and annual plan update expense $8,000 Potential Future Expenses
Capital cost to install Full Capture System devices in select areas $80,000 Annual maintenance for Full Capture System devices in select areas $10,000 Attachments:
1. 250805 Ripon Trash Implementation Plan