Stormwater Regulations

Guidelines On Complying With California Stormwater Regulations For Landscape Contractors

Landscape contractors and members of the green industry should have a special connection to water quality. Contractors particularly should be aware of the law, understand the best management practices and how to apply them, know how their operations can contribute pollutants, and be able to manage their activities and employees. Landscape contractors should be proactive, not reactive. Staying in compliance and making a difference doesn’t always mean spending dollars. Sometimes it’s just a matter of having pride in what we do.

These guidelines are intended to provide a range of general information about stormwater quality best management practices and related issues faced by landscape contractors on job sites in California. These guidelines do not address site-specific applications or the entire scope of federal, state and local regulations. Landscape contractors must consult with a stormwater professional to determine the applicability of the information provided for any general use or site-specific purposes.

Users of these guidelines assume all liability directly or indirectly arising from using this information.

CLCA once again thanks David Franklin, CPESC, stormwater management services trainer for EnviroTech NPDES, for helping update his 2007 draft of this document.


CLCA Stormwater Guidance for the Landscape Industry

The History

On June 23, 1969, the Cuyahoga River in Cleveland caught on fire. For over 100 years, this river and others in industrialized areas ignited on occasion. Rivers served as sewer systems for industrial and human waste. Local authorities were generally powerless against the polluters as there were few legal mechanisms in place. During the 1960’s, the ecology movement was growing, images of this flaming river embarrassed the nation, Randy Newman wrote the song, “Burn on Big River”. Within a few years, the Environmental Protection Agency (EPA) was formed and Congress passed the Clean Water Act (CWA).


The Law

The Clean Water Act is a long and complex law that regulates discharges into waters of the US. The goal of this legislation was to restore and maintain the chemical, physical, and biological integrity of the nation’s waters. The CWA prohibits “the discharge of any pollutant by any person.” While this is not an achievable goal, the result of the law was to require that discharges of pollutants be done under a federal permit, administered under the National Pollutant Discharge Elimination System (NPDES). Initially, the CWA targeted wastewater discharges: wastewater leaving the pipes of factories and Publicly Owned Treatment Works (POTWs) and being dumped into waterways. Eventually, stormwater washing off of urban areas from municipalities, industrial/commercial and construction sites was recognized as a significant source of pollutants. The ongoing discovery of the types and sources of pollution and the prioritization and implementation of solutions has guided the growth of new regulations meant to improve the quality of the nation’s waters.

Federal law requires that each state identifies the beneficial uses of waters in the state (drinking, tourism, transportation, natural habitat, commercial uses, swimming etc.). Most states, including California are authorized to administer the NPDES program on behalf of the EPA in order to protect the beneficial uses. In California, the authority to regulate stormwater runoff under the NPDES system has been delegated to the State Water Resources Control Board and the nine Regional Water Quality Control Boards. The Water Board writes permits (called General Permits) in a variety of categories. Categories include: heavy industry such as transportation (airports, railroads), municipalities (cities, counties, schools, prisons etc.) having separate storm sewer systems (separate from sanitary sewers and hence the term “municipal separate storm sewer systems” [MS4s]) and construction sites disturbing over one acre of land. These entities “ask permission” to sign on to the permit covering its activities and the discharges that result. Additionally, Individual Permits are written for facilities with unique operations (a power company discharging thermally elevated waters used for cooling). The law requires that it be the owner who seeks coverage under the appropriate permit. The owner is then responsible for sub-tier workers.

Permits for municipalities are tailored for that particular urban area while following a standard template meant to ensure that all municipal permits address common concerns. Smaller and more rural municipalities are allowed to operate without gaining permit coverage for the time being. Statewide, all construction sites having an acre or more of disturbance are required to gain coverage under one General Construction Permit which is based on the commonalities that construction projects share. The site conditions and information specific to each project are addressed in a document called a Stormwater Pollution Prevention Plan (SWPPP); it is meant to be guidance for all operators on the site and so all operators should be familiar with it.


The Fines

Significant monetary fines exist. Anyone contributing to environmental pollution may end up sharing a part of the fine. Regulators prefer to be “compliance assistors”, but when they respond to a citizen’s complaint of an illegal discharge, their mindset may be more, “the learning curve is over; when is this stuff going to end?” Fine amounts have been growing as has been the inclusion of lower-tier subs in the citation process.


The Process

Landscape contractors will probably discover that their activities are regulated by two different permits: a municipal MS4 permit and a construction permit. MS4 permits require that the municipality monitors commercial operations for activities that may be contributing to pollution: restaurants washing greasy mats and allowing the wash water to flow to the storm drain, auto parts stores where customers change their oil in the parking lot and then rain carries spilled oil to the gutter and landscape contractors who store broken bags of fertilizer without protective cover, thus allowing the eventual migration of nutrients to the creeks, lakes and ocean. So, landscapers need to monitor their operation yard, vehicles and jobsites for ways to eliminate or reduce activities and practices that contribute to pollution.

Landscapers who work on projects disturbing an acre or more are required to operate under the State General Construction Permit (CGP). As mentioned earlier, site specific guidance is contained in the project’s SWPPP. The SWPPP is required to be onsite for review and adherence. Information on SWPPPs is outlined below.

While the state of California enforces the federal Clean Water Act, it is free to add on regulations that are stricter. Since 2010, stormwater management requirements have been raised to a level not seen before in the United States. Regulations have defined key roles for stormwater practitioners (QSPs) and SWPPP developers (QSDs). These individuals are required to have ongoing formal and informal training. Along with the property owner, they are responsible for protecting the environment. In California, all construction projects disturbing over one acre must utilize a QSP and a QSD. If your company works on CGP projects, document the environmental training of your staff. It will be needed for inclusion in the SWPPP and it will reflect positively on your firm.

Finally, local ordinances may exist which are more strict than federal or state laws. Every landscape contractor should contact the local jurisdictions where they work to find out what local rules may apply. Check the stormwater webpage or call the stormwater manager.


The Methods

After having identified the beneficial uses of the state’s waters, California maintains a program of identifying what pollutants are impacting the waters and what human activities contribute those pollutants: agriculture contributes sediment, pesticides, nutrient runoff etc; livestock operations contribute bacteria; transportation departments contribute heavy metals from brake wear, hydrocarbons from oil drips etc. It’s at this point that solutions for preventing pollution releases to the waters need to be developed; in the same way that farmers needed to learn during the dust bowl days to plant windrows of trees to prevent erosion from wind. Public sector interests such as the EPA and private sector interest such as home building associations have developed products and practices to minimize or eliminate pollutant discharges. These are called BMPs (Best Management Practices). Some examples of product BMPs are silt fence, erosion control blankets, hydroseeding, gravel bags at drain inlets and storage containers for preventing rain from coming in contact with chemicals. These are sometimes referred to as “structural BMPs”. “Non-structural BMPs” are good habits or practices or strategies.

Some examples are doing routine vehicle maintenance under controlled shop conditions rather than on a construction site, educating employees on stormwater issues upon hire and specifically as jobsite issues arise, and scheduling soil disturbing activities to the dry season or between storms and stabilizing the ground as soon as possible to prevent erosion from rain and wind. BMPs are also divided into categories of “temporary” or “permanent”. Temporary straw applications are used until permanent sod is installed. California now requires that specific BMPs must be used and as such, operators are obligated to select these minimum BMPs and others that will be most effective for their operations. Selecting these BMP solutions can be challenging as one site may differ greatly from the next. In addition to BMP selection and use, certain strategies have become standard operating procedures for the stormwater industry: i.e. do not place a portable toilet on top of a drain inlet and when fueling equipment, use a location at least 50 feet from the site’s discharge locations (in case of leaks or spills) and don’t expose more landscape than can be protected in the event of rain. To this end, many different agencies and associations across the country have developed manuals on BMPs and stormwater management strategies. Sharing and borrowing has generally been common. This has bettered the industry and minimized the need to “re-invent the wheel”. It is typical for guidance manuals to include the following sections for each BMP:

  1. a description
  2. typical applications
  3. limitations
  4. specifications
  5. inspection, maintenance and repair requirements


For landscapers, the operations yard and the construction site are the usual areas of concern.

At the operations yard, the following BMPs are typically employed:

  1. Material Usage: keeping chemicals, auto fluids, etc. under cover of roof or tarp, and elevated if flowing rainwater may come in contact with them and contained on the perimeter in case spills occur. Having a spill response plan and materials (absorbents) available and staff trained on using them is another part of the BMP.
  2. Waste Management: proper disposal of wastes, using dumpsters with lids that are kept closed, preventing rain from leaching pollutants from materials stored in truck beds.
  3. Equipment and Vehicle Maintenance: preventing spills, repairing leaking equipment etc.
  4. Education is a best management practice, too: training your people.


On a construction site, landscape crews should be familiar with the SWPPP and the best management practices for that site. The SWPPP is the master plan and is usually composed of a binder and drawings. The binder will include required forms, site info, inspection reports, responsible persons, all the subcontractors on site, the selected best management practices etc. The drawings will show locations for the best management practices. Here are some typical best management practics found in a SWPPP.

  1. Stockpile Management: covering stockpiles and protecting from storm flow erosion at the base. This includes keeping materials out of the gutter flow zone.
  2. Street Sweeping: sweeping at day’s end or more often if needed since sediments can migrate off site via vehicle tires.
  3. Material Usage: same as for the operations yard.
  4. Erosion Control: quality landscaping is erosion control. If the finished landscape is not done, stabilize exposed soil with straw, blankets, plastic sheeting etc.
  5. Wind Erosion Control: use water or physical cover (blankets, etc) to prevent wind erosion. The local Air Quality Agency and the neighbor with a clean pool frown on such erosion. Contact the local agency for additional requirements.
  6. Sediment Control: preventing erosion control is not always possible on an active site with exposed soil and so sediment control measures are used. Gravel bags, fiber rolls, silt fence, sediment ponds, are meant to remove sediment that has mixed with water. A common misconception is that these measures filter out sediment as water passes through the silt fence for example. While some amount of filtering may occur, all good filters clog and so these measures primarily are meant to work by ponding the water. Successful installation means building a water retaining structure. Heavier sediments, such as sand, settle out of the water. The longer water can stand still behind a straw roll, the better the chance that sediments will separate (via the process of settling)from the water with which it became mixed.
  7. Non-stormwater: If it doesn’t rain and there is a discharge, it is a non-storm discharge. It is very common on construction sites to have significant amounts of runoff leaving new landscapes that are being over-watered by irrigation systems. Irrigation runoff should be eliminated; otherwise, it should be minimized and not allowed to pick up pollutants prior to discharging offsite (don’t put your pile of topsoil in the gutter flow line).
  8. Non-structural:
    1. Scheduling: avoid working on disturbed soils in the rain if you cannot prevent sediment-laden discharge from leaving the site.
    2. Protecting Existing Vegetation: limit the areas to be disturbed and protect the roots of heritage trees. Use fencing (orange) to protect Environmentally Sensitive Area (ESA).
    3. Education: inform your field and office staff concerning stormwater issues. When the person answering your phone knows key words and concepts, your company image grows.


Here are some other important guidelines for preventing pollution:

  1. Locate and protect discharge points on the property (drain inlets, gutters flowing off site) and keep operations away from them or a keep buffer zone in case spills occur. Do not store soils, materials, etc. in the gutter where flows will carry off material. Avoid using leaf blowers to push debris into drain inlets.
  2. Become knowledgeable in the proper selection and installation of products and materials for erosion and sediment control (ESC). Misunderstanding and misapplication is incredibly common and reflects poorly on the industry; the resulting pollutant discharges might be greater than having done nothing!
  3. Don’t damage the best management practices others have installed. Use them where appropriate. Cement washouts are not a place to throw solid waste, including concrete rubble.
  4. Use appropriate irrigation designs to reduce the potential for erosion and pollution runoff.
  5. Follow all federal, state, and local laws and regulations governing the use, storage, and disposal of chemicals and training of applicators and pest control advisors:
    1. Follow manufacturers’ recommendations and label directions.
    2. Where practicable, use pesticides only if there is an actual pest control problem (not on a regular preventative schedule). When possible, use less-toxic chemicals that will get the job done in the minimum amount necessary.
    3. Never apply chemicals during or immediately before predicted rain or wind events, or anytime when wind exceeds 5 MPH.
    4. Do not mix or prepare chemicals for application near storm drains.
    5. Do not apply any chemicals directly to surface waters unless the application is approved and permitted by the state. Do not spray within 100 feet of open waters.
    6. Apply methods to minimize off-target application (e.g. spray drift), including consideration of alternative application techniques.
    7. Sweep pavement and sidewalks if chemicals are spilled. Do not hose spills down the gutter.
    8. Store all chemicals in closed, labeled containers and keep them off the ground.
    9. Properly dispose of used chemical containers.


The Results

Landscapers, as members of the Green Industry, likely have a special connection to the environment. As professionals, we’ll need to know about water quality laws, know how our operations might be a source of pollutants that migrate to the environment, manage our activities and employees and know about and how to use best management practices. Be proactive, not reactive. Being compliant and making a difference doesn’t always mean spending dollars. Sometimes it’s just a matter of having pride in what we do.



These guidelines are intended to provide a range of general information about stormwater quality best management practices (BMPs) and related issues faced by landscape contractors in California. Due to many regulations and site-specific issues, these guidelines will not address all matters of compliance. Landscape contractors must seek advice from a stormwater professional to determine the applicability of the information provided here for their specific needs. Users of these guidelines assume all liability directly or indirectly arising from using this information.