Storm Water Management

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Santa Monica Bay and its beaches are highly valued recreational resources to Manhattan Beach residents and visitors. However, these resources are impacted by polluted storm water and urban runoff, which enter the storm drain system and are ultimately discharged untreated, directly into the ocean. Pollutants such as motor oil, trash, fertilizers, pet droppings and soap residue can be generated from simple daily activities such as parking and washing a car, taking out the trash, maintaining landscaping, or walking the dog. Once in the ocean, they adversely affect not only aquatic and avian species, but also people. Cleaner oceans mean a healthier environment for everyone.

City Programs & Policies

Manhattan Beach has 24.1 miles of storm drains within its jurisdiction. Many of the City’s largest storm drain lines (8.5 miles) are owned and operated by the Los Angeles County Department of Public Works (LAC DPW), while the City owns and maintains the remaining 15.6 miles of smaller storm drains, and all 505 associated catch basins. As required by the municipal NPDES permit (see Storm Water Regulations side bar), Manhattan Beach has implemented many measures to control polluted runoff from reaching the ocean. These include:

  • Adopting municipal code requirements to ensure the health, safety, and general welfare of its citizens and its coastal receiving waters, and modifying City building code requirements to control pollution generated by construction activities. (See the Sustainable Development section for more information.)
  • Implementing a multi-faceted public education program to inform residents and businesses of how they can partner with the City in pollution prevention.
  • Implementing pollution control measures and devices in the City’s streets and catch basins to control urban runoff.
  • Constructing dry-weather, low-flow storm water diversions to the sewer system.
  • Implementing measures to comply with the municipal NPDES permit requirements to control and/or eliminate sources of bacteria contamination.
  • Conducting commercial business inspections targeting industries whose activities have been identified as contributing to the urban runoff pollution (e.g., restaurants, auto repair shops, and gas stations).
  • Identifying and terminating illicit discharges to the storm drain system.
  • Modifying City facilities and maintenance activities to reduce and/or eliminate polluted storm water runoff from reaching the ocean.

Storm Water Regulations

In 1970, the Environmental Protection Agency (EPA) was created “as an independent regulatory agency responsible for the implementation of federal laws designed to protect the environment.” Soon after its formation, EPA enacted the landmark Federal Water Pollution Control Act, more commonly known as the Clean Water Act (CWA), to regulate polluted discharges into the nation’s water bodies.

One component of the CWA is the Municipal Storm Water National Pollutant Discharge Elimination System (NPDES) program. Administered under the umbrella of the California State Water Resources Control Board, municipal NPDES permits are issued to cities and counties setting the framework and minimum standards for operating and maintaining municipal storm drain systems in a manner that minimizes the discharge of pollutants to surface waters.

In Los Angeles County, a single municipal NPDES permit is issued approximately every five years to the County of Los Angeles, Department of Public Works and 84 cities incorporated within its jurisdiction. The City of Manhattan Beach is one of the cities covered under the County’s municipal NPDES permit, and is therefore responsible for the quality of untreated surface water discharges reaching Santa Monica Bay from sources within the City.

Municipal & City Building Code Requirements
One component of the municipal NPDES permit calls for cities to develop a list of and require the implementation of best management practices to infiltrate, filter, or treat polluted runoff from all development projects one acre or greater in size. It also applies to smaller projects that meet certain criteria, e.g., auto repair shops, gas stations, or restaurants of 5,000 square feet or more, and parking lots of 25 spaces or more. This is found under the permit’s Standard Urban Stormwater Mitigation Plan (or SUSMP) provisions. To meet this permit requirement, a SUSMP ordinance was adopted by City Council in 2000.

Development projects in Manhattan Beach subject to SUSMP must incorporate design features and structural controls to minimize the impact of the final project on water quality. Because Manhattan Beach is a predominantly built out city with a high percentage of residential properties less than one acre, its development projects rarely trigger SUSMP provisions. Last fiscal year, the City processed only three SUSMP plans, and has a total of only five SUSMP plans within the community.

The City has begun to require that projects implement additional pollution mitigation measures beyond that which is required in the municipal storm water permit. For example, a City ordinance requires that trash enclosures for commercial establishments be covered and outfitted with drainage plumbed to the sanitary sewer system. This approach prevents rain from entering the trash enclosure, and it allows the enclosure to be steam cleaned without adversely impacting water quality at the beach.

Public Education & Outreach
Manhattan Beach employs a wide range of approaches to educate the general public and businesses about sources of and ways to reduce storm water and urban runoff. These include hosting/attending public events, conducting presentations at schools and other forums, maintaining a comprehensive website, providing educational materials, running media ads, implementing a restaurant certification program, and conducting regular mailings to residents. For example:

  • Community events such as Earth Day and the Hometown Fair raise awareness about storm water pollution, its sources and what can be done to prevent pollution from entering storm drains and reaching the ocean.
  • The City’s Environmental Programs webpage provides brochures about the residential, commercial and construction storm water best management practices as well as links to storm water regulatory agencies.
  • Educational brochures and other materials promote storm water pollution prevention. They are distributed at the public counters in City Hall and the Public Works yard, as well as by City employees in the fi eld when they observe residents, restaurants, and/or contractors practices being implemented that may contribute to storm water pollution. The City also provides restaurants and other businesses calendars featuring storm water best management practices.
  • Newspapers and cable television (e.g., the Beach Reporter and Public Access Channel 8) promote proper litter abatement, used oil recycling, and use of the S.A.F.E. household hazardous waste facility.
  • The City’s restaurant certification program educates local restaurants about storm water runoff and how their activities can adversely affect our local beaches and ocean. It also promotes best housekeeping practices to reduce improper and contaminated discharge from food service activities.

More information about the City’s education and outreach efforts can be found in the Solid Waste & Recyclables section of this report; it highlights the City’s trash, household hazardous waste, recycling, composting, and water conservation efforts, all of which have the potential to impact storm water quality.

Pollution Control Measures: Street Sweeping, Catch Basin Cleaning & Pollutant Excluder Devices
Street sweeping is a source control measure used to remove trash, debris, sediment and any pollutants attached to the sediment (e.g., metals, grease, bacteria) from City streets, in particular near curbs and gutters. The City implements this program through a contract with Cleanstreet. All public streets, paved public alleys, the Strand and specified parking lots are swept regularly, typically weekly or more often if needed. To make sure streets are swept where pollutants are most likely to accumulate, “No Parking During Street Sweeping” signs are posted on many of the City’s streets and enforced daily by the City’s police Community Service Officers (CSOs), who issue citations to violators. Street sweeping is less effective where residents have opted out of having the signs posted because sweeper trucks must circumvent parked cars and thus the location where pollutants typically accumulate. Approximately 35% of streets do not have signs posted.

Residents can petition to have street sweeping signs removed if at least 66% of the residents on a defined block are in favor of the action. Likewise, where no signs are posted, 66% of the residents must be in support of having them installed.

The City’s catch basins provide a direct point of entry for pollutants into the storm drain system. To control pollution, Manhattan Beach cleans its catch basins according to a schedule which prioritizes areas within the City. Basins which typically accumulate more debris and are located near the beach are considered Priority A basins, of which the City has 42. These catch basins are cleaned at least four times per year (more if needed). An additional 57 Priority B catch basins are cleaned twice per year and the remaining 376 Priority C catch basins are cleaned once per year. Some of our catch basins have also been retrofitted with pollutant removal devices depending on the pollutant of concern. For example, five catch basins are equipped with insert devices to capture trash, and one catch basin near a commercial automotive facility also has an absorptive pad to absorb hydrocarbons. Lastly, the City uses “No Dumping - This Drains to Ocean” permanent markings over catch basins to educate residents and encourage them not to dump waste into them. The markings are inspected annually and replaced if needed.

Within the City, ten hydrocarbon oil clarifiers have been installed to separate the free phase oil and grease from runoff; two are located at the Public Works Maintenance Yard (see City Facilities below), three at private automotive facilities and five in local commercial developments. In addition, two commercial developments, Sketchers and Metlox, have subterranean parking and were required to install clarifiers per the City code.

Ten Continuous Deflection Separators (CDS units) have been installed on the City’s major storm drains located near ocean outfalls, at Polliwog Park, and at other strategic places throughout the City. These units intercept and capture trash and debris in the storm drain system before it washes out to the beach, and are considered state-of-the art for trash and debris removal. Absorbent pads used to collect oil and hydrocarbons are replaced in the CDS units each time they are cleaned. The City’s CDS units were cleaned twice in 2006/07 and there was 36 cubic yards of debris removed from the units. The used absorbent pads are disposed of as hazardous waste. In 2006, the CDS units prevented 19 cubic yards of trash and debris from washing out to the beach.

Dry Weather Diversions

Dry weather diversions are designed to utilize excess capacity in the sanitary sewer system to treat dry weather runoff as well as so-called first flush low flows of storm water. These dry weather/low flow diversions are typically permitted by the Los Angeles County Sanitation Districts (LACSD) to operate only during summer and only at night when there is excess capacity in the sanitary conveyance and treatment system. This practice is particularly helpful because capturing and diverting contaminated dry weather flows helps improve beach water quality during the summer when recreational beach use is highest. The first flush of storm flows often contains the highest concentrations of pollutants and bacteria observed during a rain event, so to the extent these first flushes can be diverted, the overall pollutant load reaching the ocean is reduced.

Flow Diversions & Infiltration
Manhattan Beach has three mechanical storm water diversions; two are located at the outlet of the City’s two largest storm drains, 28th Street and Manhattan Beach Pier, and one is at Polliwog Park. Both the 28th Street and Polliwog Park diversions have special permission from LACSD to operate year-round, with the Polliwog Park diversion permitted for 24-hour operation. Rain sensors disable the diversion pumps whenever they sense that 1/10” or greater of rain has fallen. The Manhattan Beach Pier diversion, or “Pier Weir,” pre-treats the runoff by removing oils, grease and heavy metals prior to diversion. In fiscal year 2005/06, approximately 473,000 gallons of runoff that would have otherwise discharged to the ocean were diverted to the Los Angeles Sanitation Districts; in 2006/07 some 2.6 million gallons of runoff were diverted. The City is currently evaluating the reasons for and sources of the five-fold increase in dry weather flows discharging through the diversions.

The City also installed approximately 25 new catch basins along The Strand designed with open bottoms to allow infiltration of dry and wet weather low flows into the underlying sandy soil. This is effectively another diversion which utilizes the natural sandy soil to divert and treat runoff which would otherwise discharge at beach outfalls near the shoreline.

“A TMDL is a calculation of maximum amount of a pollutant that a water body can receive and still meet water quality standards.” (EPA).

TMDLs are pollutant specific; the City of Manhattan Beach must comply with the bacteria TMDL.

Bacteria Control Measures
Manhattan Beach is subject to the bacteria total maximum daily load (TMDL) limitation set by the Regional Water Quality Control Board (Water Board). This TMDL requires the City to meet certain bacteria discharge limitations in dry-weather (May-November) storm water and urban runoff discharges. However, some exceedance violations are allowed in the winter rainy season. It is likely that these limits will be included in the new municipal NPDES permit to be issued in 2008. There is no single strategy that completely insulates the City from discharges to the ocean. Recognizing the need to minimize the potential for exceeding bacterial limits, the City has established a multi-faceted program that includes the efforts highlighted both above and below, including but not limited to flow diversions and infiltration, pollution control measures, and commercial business inspection programs.

Most strategies fall into one of two categories: 1) controlling pollution at or near the source, such as street sweeping, restaurant programs, retention/infiltration basins, and 2) end-of-pipe solutions, such as storm water diversions and CDS units. Storm water diversions, however, have obvious limits during high flow storm events because only low flows are permitted into the sanitary sewer system. More promising are the efforts being made to reduce flow by using and promoting infiltration techniques on both private and public property. Staff continues to explore opportunities to promote private, on-site infiltration, and has already initiated a pervious pavement project at eight municipal lots. Siting infiltration systems that can accommodate flows from larger watersheds will become an even great focus as we continue our efforts to meet the bacteria TMDL requirements.

Commercial Business Inspection Program
Restaurants have been identified as likely contributors to storm water pollution, particularly for bacteria or nutrients that feed the growth of bacteria, through improper cleaning practices or poor housekeeping that allow food particles, oil, grease, trash and cleaning products to flow into the street, gutter and/or storm drain system. Problematic activities include washing kitchen mats outside, not maintaining trash enclosures, leaving trash bins and grease receptacles uncovered, and dumping liquid waste into trash bins. Restaurants may also discharge excessive quantities of fats, oil and grease into the sanitary sewer system which can cause blockages and contribute to sewer overflows. New food establishments are required to construct covered trash enclosures to prevent trash and debris from entering the storm drain.

The municipal NPDES permit requires that cities inspect restaurants twice within each five year period.
Restaurant Certification Program
In cooperation with the Bay Foundation, Manhattan Beach, along with Hermosa Beach, Redondo Beach, and Torrance, has implemented the Clean Bay Restaurant Certification Program targeting food service establishments that have the potential to impact storm water. The Bay Foundation developed a comprehensive 28-point storm water inspection checklist that requires 100% compliance in order to receive Clean Bay Restaurant Certification by the Bay Foundation; it far exceeds the minimum requirements of the municipal NPDES Permit. During 2006/07, the City of Manhattan Beach inspected all of its restaurants using the checklist and conducted follow up inspections for those that did not achieve certification during the first inspection. Seventy percent of Manhattan Beach’s food service establishments earned this award in its first year of implementation. Restaurants achieving the certification are provided a Clean Bay Restaurant certificate and encouraged to post it in a highly visible location such as in a window near entrances. The Bay Foundation also publicizes the names and locations of Clean Bay certified restaurants on its website and through press releases.

Storm drainIllicit Discharges
The City strictly enforces the prohibition against illicit discharges, which are defined as any material other than storm water that gains entry into the storm drain system, unless the discharge is explicitly exempted under the municipal NPDES permit. Examples of illicit discharges include dirt and debris from construction projects, restaurant oil and grease disposed of outdoors, swimming pool water that is not properly dechlorinated, household hazardous waste (motor oil, paint) and dirty, soapy water. Manhattan Beach’s Illicit Connections and Illicit Discharges Elimination (IC/ID) Program documents, tracks and reports all such reported cases. This allows the City to monitor trends in types and frequency of illicit discharges and to target public education activities toward problematic behaviors.

Public Works’ inspectors typically inspect for and respond to illicit discharges entering the public rights-of-way, although such discharges may be reported by City employees or citizens. In the event of an illicit discharge, the responding officer, inspector or employee will give instructions to the violator to clean the spill by a specific time and will issue a warning notice or citation. If the clean up does not occur as requested, a citation and/or contact with the appropriate City department or agency is initiated for clean up assistance. The City identified 27 illicit discharges in FY 2006/07, eleven of which were issued Violation Warning Notices. All illicit discharges were cleaned up promptly.

City Facilities
The City’s Public Works maintenance yard has two vehicle wash pads which direct low flow runoff to a clarifier for pretreatment to remove oil and grease, and then to the sanitary sewer. A second clarifier is combined with a CDS unit equipped with floating filters to capture hydrocarbons and debris from parking lot runoff.

The City is also in the process of converting 130,000 square feet of impervious public parking lot space to pervious pavement which will effectively infiltrate rainfall without generating runoff. This project has been made possible by a $900,000 grant from the State Water Resources Control Board awarded in 2006.

The City is currently designing a cover to be constructed over the upper portion of the Public Works maintenance yard where material stockpiles, trash and waste are stored until they are hauled off. Once completed, the cover will prevent the trash and waste from mixing with rainwater, effectively eliminating contaminated runoff from this site.

Lastly, Manhattan Beach provides 20 “mutt mitt” stations throughout its parks, dog runs, The Strand, and greenbelt to encourage pet owners to pick up after their pets. Pet waste (bacteria) is a significant contributor to storm water pollution if left on the ground and mixed with storm water or urban runoff.

Other Notable Programs

Pollution Control Measures

Street Sweeping
Many local cities have enhanced street sweeping programs, which include increased street sweeping frequency, more thorough coverage and additional focus on commercial districts. Additionally, other cities do not allow an opt-out program, thereby effectively sweeping every street near the curb where pollutants are likely to accumulate.

Catch Basins
Locally, catch basin inserts and catch basin screens/debris excluders of all types are among the most commonly installed municipal best management practices to control trash from entering the storm drain system. Cities subject to the trash Total Maximum Daily Load (TMDL) requirements are particularly compelled to install such devices for trash removal. For example:

  • The City of Los Angeles has installed 9,970 catch basin inserts along with 7,278 catch basin screens.
  • Santa Monica has installed 500 catch basin inserts.
  • West Hollywood has installed 195 catch basin debris excluders along with 57 catch basin inserts.
  • Hermosa Beach has installed 41 catch basin inserts in high priority areas (downtown near the ocean and the beach) to collect and dispose of trash. Monitoring of annual catch basin cleaning records assists in properly categorizing catch basins for priority and determine if they should be either promoted or demoted in terms of frequency of cleaning.
  • Six other regional cities have installed between 5 and 70 catch basin inserts.
  • The County of Los Angeles has installed a significant number of catch basin inserts in County-owned catch basins.

Pollutant Excluder Devices
A total of 105 gross pollutant separators (69 CDS units and 36 Stormceptor units) have been installed within the Santa Monica Bay-Ballona Creek watershed management area (including those installed in Manhattan Beach). Other cities in this watershed management area, as defined by the Regional Water Quality Control Board, include: Beverly Hills, Culver City, El Segundo, Hermosa Beach, Los Angeles (portion of), Palos Verdes Estates, Rancho Palos Verdes, Redondo Beach, Rolling Hills, Rolling Hills Estates, Santa Monica and West Hollywood.

Flow Diversion & Infiltration
Many cities, including Manhattan Beach, have installed a variety of structures and devices to capture, infiltrate and/or divert urban runoff flows, including infiltration trenches, porous paving, bioretention facilities, biofilters, cisterns/dry wells, clarifiers, downspout filters, infiltration pits, synthetic turf, vegetated swales, wet ponds, and grease interceptors. The City of West Hollywood retrofitted one of its municipal parking lots with pervious pavement three years ago. The parking lot has since experienced heavy rains and has proven to be a successful project.

Commercial Businesses
Many cities have a fats, oil & grease (FOG) program (and related ordinances) to eliminate improper discharge of these contaminants to the sanitary system. They require grease control devices for restaurants and other food service establishments to reduce the discharge of FOG into the sanitary sewer system, thereby reducing the incidence of sanitary sewer blockages and overflows that may reach the storm drain system and ultimately the ocean. This FOG program will soon be required of all cities under new state requirements.

SUSMP Requirements
Under its Urban Runoff Pollution Ordinance, the City of Santa Monica has expanded its definition of the types of new and redevelopment projects that must implement the SUSMP requirements identified in the municipal NPDES permit. For sites less than one acre, SUSMP requirements now apply to:

  1. A vacant site or a site where 50% or more of the square footage of the structures is removed prior to construction.
  2. A site where the owner is making repairs, alterations or rehabilitation in an amount exceeding 50% of the replacement cost of the building or structure.
  3. A project which will result in improvements to 50% or greater of the square footage of a building, creates or adds at least 5,000 square feet of impervious surfaces, or creates or adds 50% or more of impervious surfaces.
  4. A City project which would not otherwise be required to comply with the urban runoff ordinance (via 1-3 above) but where runoff controls are feasible and economical.

This definition effectively requires all new single family homes, as well as any significantly remodeled homes, to meet SUSMP standards.

New developments in Santa Monica are also strongly encouraged to incorporate design elements to maximize infiltration as part of compliance with the SUSMP treatment volume standards. These include maximizing permeable surfaces, redirecting runoff to permeable surfaces and/or storage containers, and removing or designing curbs, berms, etc. to provide access to permeable and landscaped areas.

Programs & Practices for Future Consideration

Pollution Control Measures

Ensure street sweeping signs are installed on all City streets
The City should consider eliminating its opt out petition program and make mandatory the posting of street sweeping signs on all public streets and alleys. This would result in cleaner streets and effectively reduce the amount of pollutants reaching the storm drain system and ultimately the beaches and ocean.
Cost: $ Feasibility Rating: 3

In high priority areas of the City, install devices to reduce or eliminate trash from entering the storm drain system and/or reaching the ocean
Evaluate the maintenance needs of and consider the following: 1) placing trash excluders/screens over catch basin inlets, which are designed to remain closed during dry weather but are spring loaded to open under heavy rain conditions to prevent flooding; 2) installing filters on storm drains that discharge directly onto the beach; 3) installing CDS units near large outfalls where there is no dry weather diversion.
Cost: $$$ Feasibility Rating: 1

Flow Diversion & Infiltration

Evaluate additional opportunities to divert contaminated dry weather flows
Although the City has constructed several dry weather diversions, there are additional locations where diverting flows to the sanitary sewer system are desirable. One example is the 1st Street storm drain, which discharges flows near the shoreline. Available sewer line capacity and accessibility are required elements for any diversion opportunity identified for consideration.
Cost: $$$ Feasibility Rating: 1

Evaluate additional storm water infiltration opportunities
Where dry weather diversions are not feasible, consider appropriate locations to infiltrate dry weather and first flush storm flows. The sandy soils present in Manhattan Beach, particularly in areas west of the greenbelt, are optimal for such solutions. Also investigate the possibility of diverting low flows from CDS units to the sand for percolation.
Cost: $$$ Feasibility Rating: 1

Commercial Business Inspections

Enhance the City’s current business inspection program for key sectors
Consider enhancing publicity, public awareness and understanding of the City’s Clean Bay Restaurant Certification program and give restaurant owners and managers greater incentive to participate. Also consider enhancing the program to address fats, oil & grease (FOG) by requiring control devices for restaurants and other food service establishments to reduce FOG discharges into the sanitary sewer system. This would reduce the likelihood of sanitary sewer blockages and overflows that can occur when FOGs are inappropriately discarded, and also reduce the maintenance resources required by the City to inspect the adjacent sewer pipes. An enhanced FOG program is part of the Sewer System Management Plan being developed for the City under a separate regulatory program for sanitary sewer collection systems.
Cost: $$$ Feasibility Rating: 1

Illicit Discharges

Increase enforcement and monitoring to reduce illicit discharges
Consider enhancing public education about what constitutes illicit discharges and focusing on those sectors most often violating the City’s illicit discharge ordinance.
Cost: $$ Feasibility Rating: 2

City Facilities

Evaluate opportunities to upgrade City facilities and/or operations to reduce
contaminated runoff
At a minimum, consider installing or implementing the following at City-owned facilities: 1) installing a re-circulating car wash system at the maintenance yard to save water and filter/reuse it prior to discharge to the sanitary sewer; 2) installing underground storage tanks or injection wells to catch runoff and allow water to percolate (or be pumped) into the soil; 3) developing site-specific percolation basins to catch and infiltrate storm water runoff; 4) retrofitting more parking lots with pervious pavements and other pollutant capturing devices.
Cost: $$$$ Feasibility Rating: 1

Municipal & Building Code Requirements

Consider further modifications to municipal and building code requirements that effectively target pollutants of concern
Areas for consideration include: 1) enhancing trash enclosure requirements, 2) maximizing retention of storm water on-site to reduce contaminated runoff, and 3) imposing administrative penalties for SUSMP violations.
Cost: $$$ Feasibility Rating: 3

Consider establishing a revenue stream to support the implementation of storm water pollution control requirements
Approximately every five or six years, the municipal storm water NPDES permit is readopted. With each cycle, the Los Angeles Regional Water Quality Control Board modifies and adds additional storm water pollution control requirements that cities must comply with to control storm water and urban runoff pollution.

The City’s capital and operations needs, as well ensuring compliance with the municipal NPDES regulations, are rapidly exceeding the City’s financial ability to fund other much-needed improvements. Compounding the problem, any storm drain fee increase must be approved by residents under Proposition 218 guidelines, thus limiting our ability to increase fees as an additional revenue stream. Absent a rate increase, other funding sources should be evaluated to create a long-term viable source for storm water NPDES compliance.
Cost: $$ Feasibility Rating: 3