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Pollution Prevention at Home

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Hiring a Gardener

Aerial image of gardening tools on a lawn

Know what you are paying for and what impact it has on the environment. Gardeners frequently state that they would adopt environmentally preferable lawn care practices if their customers didn’t insist on "business as usual". Read the suggestions below and choose the practices that you would like your gardener to follow. Keeping your yard healthy will not only save you money but will protect your family’s health and the environment.

Make sure that you and your gardener understand that when debris enters the storm drains, it flows to the creeks where it decomposes, dropping oxygen levels in the water too low for fish to survive. Sediment from our yards usually accompanies the debris, which causes the creeks to be over silted, greatly impacting the environmental health of our waterways.

Inquire if the gardener is a licensed landscape contractor. Often, when gardeners are licensed, their license number is displayed on their business cards and on their vehicles. When serious pest infestations do occur, call a licensed pest control operator and inquire if their practices are less-toxic. Ensure that your gardener is knowledgeable in pest identification and disease diagnosis as well as Integrated Pest Management (IPM). IPM is a decision-making process that encourages people to use environmentally compatible techniques and products. IPM recognizes that pests are part of our ecosystem, but seeks to prevent damage from pest populations reaching unacceptable levels. Regular monitoring and record-keeping of pest populations become a valuable reference to establish your own personal tolerance level. Once a pest infestation reaches beyond that threshold, a decision can be made as to which means of control will be used: cultural (modification of plant care activities, water, plant placement, and pruning), physical (picking the pests off the plants by hand), mechanical (use of a weed-block or sticky traps), biological (use of beneficial insects to prey on harmful insects) or chemical (use of least toxic pesticides where serious damage would be done). 

When applying pesticides, please know that “the label is the law”, which means it is unlawful and environmentally unsound to use the pesticide in any manner other than how it is stated on the label. Pesticides are labeled either Caution, Warning, or Danger. Even with Caution-labeled pesticides, there are safety practices users should follow.

Quick Tips for Designing your lawn and garden

  • If you have a yard that is being re-designed or hasn’t been landscaped yet, you have an opportunity to be well-informed about the best foundation for your garden.
  • Select plants that grow well in our local environment while considering growth patterns and maintenance requirements to help your garden achieve and retain its optimal health... in other words, use the right plant in its right place.
  • Healthy plants have the most resistance to pest infestation. Looking at the plants and noting any changes in their condition will provide an opportunity to address any problems before the situation is serious.
  • Minimize annual flowers, which require as much water as a lawn and must be replaced 3-4 times each year.
  • Choose California native and Mediterranean-climate plants first. They are drought tolerant and hardy in this area.

Quick Tips for Lawn Choice and Care

  • Consider lawn alternatives that can handle some foot traffic: Caraway-Scented Thyme, (which doesn’t require any mowing), Woolly Yarrow, Mother of Thyme, O’Connor’s Legume, or Garden Chamomile.
  • Plant Tall Fescue, Dwarf Tall Fescue, Red Fescue, and Perennial Ryegrass. These are preferred grasses in the Bay Area that require fewer inputs of water, fertilizer, mowing, pesticide, and maintenance time and are referred to as “cool-season” grasses.
  • Where you have an existing lawn, familiarize yourself with what soil and grass type you have. Know the potential problems and pests of your grass. Learn what time of year to monitor for those pests. When treatment is called for, select the least-toxic method as a preventive measure, rather than waiting until the problem requires more aggressive treatment.
  • Consider some of the following and give your gardener clear instructions on how to maintain your lawn. These will help build fertile soil and vigorous, deep-rooted lawns. A healthy lawn can resist disease and drought damage, and out-compete most weeds without reliance on chemicals. An unhealthy lawn (or any tree or plant) is prone to attacks by pests.
  • Use a mulching mower that leaves grass clippings on the lawn which provides free fertilizer, keeps refuse charges down, and helps lawns grow more green and dense.
  • In fall and spring, aeration of the lawn by hand or with a power aerator eliminates thatch build-up and allows water to penetrate to the root zone.

Maintenance Practices

Another option when there is an advanced pest infestation or disease on an annual or perennial is to remove and replace the plant. It may be that the environmental cost of applying chemicals in this situation is greater than removal and replacement. Analyze if the plant is in its preferred location, with proper soil, moisture, and sun.

Checklist for your gardener

If your landscaper or gardener also designs and chooses your plants:

  • Analyze and prepare the soil for planting using appropriate amendments, tillage, and grading.
  • Design and plan the garden based on how it will be used, water efficiency, ease of maintenance, and low waste.
  • Design and install the irrigation system to efficiently water desired plants, minimizing weeds, waste, and costs.
  • Use the right plant in the right place. Plants are healthiest when placed in their preferred environment. Consider the sun exposure and shade received amount of irrigation needed, and pruning practices.
  • Plant insectary plants – those that attract beneficial insects to your yard to prey on harmful insects.
  • Maintain the perennial lawn without seeding with annual grass, retaining the drought-tolerant, lower-maintenance perennial grass lawn.
  • Set mower height up to 2 - 2.5" on perennial tall fescues (1.5" on annual or bentgrass lawns) to increase drought tolerance and discourage invasive weedy grasses.
  • Aerate the soil by inserting a 6" garden fork every 4" and levering to loosen the soil. To eliminate thatch accumulation, avoid over-watering or over-fertilizing.
  • Avoid pesticides or weed killers on the lawn. Studies have shown that commonly used chemicals (quick-release fertilizers, pesticides, and weed-&-feed products) can kill beneficial soil organisms and contribute to soil compaction, thatch build-up, and lawn disease. These same chemicals harm human health, pets, wildlife, creeks, and rivers.
  • Do not apply fertilizer on perennial lawns (no more than twice per year for annual lawns, and slow-release fertilizers only). Over-fertilized lawns, blue-green in color, are unhealthy and prone to thatch build-up, pest infestation, and drought damage.
  • Use a rake or industrial-duty broom to clean up yard debris, pathways, and sidewalks. Leaf blowers cause air and noise pollution, offer less control over the debris, and require the same amount of time to do the same job by broom. Definitely don’t allow any area to be cleaned by the hosing down method. Make it clear to your gardener to avoid any debris entering storm drains.
  • Control weeds with layers of mulch, biodegradable fabric, cultivation, and water management to prevent nutrient loss and waste generation.
  • Water lawn deeply and evenly at a rate appropriate for the grass variety, climate, and season.
  • Utilize a water-conserving irrigation schedule, delivering water to the root zones and not exceeding the amount needed by the plants. Watering in the morning avoids (when the sun and wind are low) the high-evaporation rates between 10 AM - 4 PM.
  • Store fertilizers, fungicides, pesticides, and oils out of the way of rain or irrigation, as even the residues on the containers, can be washed off and into the storm drain system and flow to nearby creeks.
  • Place yard clippings in a compost pile and monitor it so that it effectively breaks down and can be used again in your yard. Or, place it in yard debris bins for pick up or ask your gardener to haul it away as part of their service. Composting provides high-quality soil and helps keep refuse fees down.

Recycling Autumn Leaves

Cloth bag filled with autumn leaves and rake in the background

Leaves clog our storm drains and reduces the capacity of our drainage ditches which adds to flooding problems every year. Overloading creeks with leaves can deplete the water of oxygen as the leaves decompose and low levels are harmful to fish. Please help protect our roads and creeks! 

Keep leaves out of gutters, storm drains, and drainage ditches that lead directly to creeks. Compost the leaves and use rich nutrients to enhance your garden.


Vehicle Cleaning

Most people aren't aware they are doing anything wrong. Whatever falls on or near the street enters a storm drain inlet and flows directly through the storm drain pipe to local bodies of water like creeks or streams. Drips, leaks, and spills of soap, oil, grease, gas, antifreeze, and other toxics used by automobiles are washed off and carried by rainfall or water to pollute our waterways.

Soap from the wash water, entering a creek through the storm drain, is harmful to aquatic life and plants. Even biodegradable soaps break down slowly and negatively impact aquatic life. Automobiles can be washed regularly without soap and lots of water by wiping the exterior with a wet cloth or paper towel. If a soap wash is necessary, collect wash water/soapy water and discharge it to a sanitary sewer through the sink or toilet or take your car to a commercial car wash where the soap and pollutants are treated.

When it rains the oils and grease are all washed off the paved areas and flow directly to the creeks and streams through the storm drains. To prevent this from happening, get all leaks fixed and cover stained areas with powder soap and cat litter to soak up the oil. Then sweep the mixture up and dispose of it in the trash.

Be careful when filling and re-filling your car with fluids because any leaks and drips will be washed into the storm drain and into creeks and streams. Clean up all of the spills with the same process as oil leaks and drips.

Recycle used oil, antifreeze, oil filters, and other household toxins.

Carpet Cleaning

If you clean your own carpets, rugs, or upholstery, please dispose of your waste down a sink or toilet. If you must dispose of your waste outside, use soil or gravel far from any ditch, gutter, creek, or inlet. Be aware that chemicals in the waste may damage plants. Please never dispose of these wastes in rainy weather as they may be washed into creeks.

If you have your carpets, rugs, or upholstery cleaned by a carpet cleaning business, please make sure your carpet cleaner both knows and follows appropriate practices. Ask your cleaner how he or she intends to dispose of waste.

Home & Garden Tips

In the yard

  • Keep your trash can/dumpster area clean and closed. Any garbage which ends up on the ground can be carried away and pollute your creeks. Use a broom, not a hose, to clean the area.
  • Minimize your use of fertilizers and pesticides around your property. If you must use them, choose less toxic alternatives. Apply in dry weather and avoid watering after use.
  • Keep lawn and yard clippings contained, away from gutters and storm drains.
  • Dispose of animal waste properly; throw it away in a garbage can or toilet.

Around Parking Areas and in Garages

  • Keep your yard, household, and automotive chemicals stored in a cool, dry place without leaks. Any old containers or leaky containers of these chemicals must be recycled or properly disposed of at a Household Toxic Waste Facility to prevent pollution.
  • Use a broom instead of a hose to clean parking areas. Auto leaks on concrete may be soaked up using kitty litter or other absorbent material, then swept up and disposed of properly.
  • Recycle used motor oil, antifreeze, oil filters, and other household toxins.
  • Soapy car wash water harms plants and aquatic life. Consider using little or no soap (even biodegradable soaps don't break down soon enough to avoid killing organisms in the creeks), and try to wash on gravel or grass. If possible, use a commercial car wash that recycles its wash water.
  • Dump the bucket of extra soapy water into a sink or toilet.

Around your home improvement projects

  • Using Concrete - Sweep up concrete, aggregate, or other dust and waste materials to throw away into the garbage. Do not rinse down the gutter. Concrete mixes have chemicals that will poison creek life.
  • Using Paint - Rinse any latex paint-contaminated brushes and rollers in the sink, not outdoors (send it to the sanitary treatment plant and not to the creek). Bring used paint thinner or any solvents or other chemicals to a Household Toxic Waste Facility.
  • Using Barbeques - The build-up of burnt food that cakes on the grill are poisonous to animals in the creeks, even in low concentrations. Avoid cleaning off grills onto paved areas which will rinse into the gutters and creeks.


Carwash Fundraisers

How can a car wash pollute our creeks?

A car wash is a great way to have fun while raising funds for your school or community group. But did you know that if soapy water enters the storm drain system it will flow directly to the nearest creek? Soap (even if it is biodegradable) is a pollutant that can be harmful to fish and other aquatic life that depend on clean water for their survival. As well as soap, car wash water can carry pollutants such as dirt, oil, and other automotive fluids into our creeks.

Is it possible to host a car wash that doesn’t pollute creeks?

Yes, you just have to select a site where the wash water can be disposed of without it entering a storm drain. The County of Sonoma can help you determine if the site is appropriate and offer suggestions on how to dispose of the water.

How do I keep car wash water from entering the storm drain system?

There are several ways you can do this. Use your imagination and the ideas below to figure out what will work best.

  • Wash the cars in a place where the natural drainage pattern will route wash water into a vegetated area such as a lawn or vacant lot. Be sure to have the owner's permission if wash water is draining onto a neighboring property. You might be able to use sandbags, rolled towels, hoses, or other materials to divert the surface runoff to the vegetated area.
  • Another way is to seal off the storm drain, collect the water, and use a small sump pump to pump the water to either a vegetated area or into a cleanout opening to the sanitary sewer

How do I seal off a storm drain?

Many parking lots have grated inlets placed in low areas. If the grate can be removed, remove it and place a sheet of heavy plastic over the inlet that extends beyond the edges. Replace the grate. Then put a heavy rubber mat or a lighter rubber mat with weights on it over the grate. Be sure to form a tight, waterproof seal that will keep all water out of the storm drain. If the grate cannot be removed place plastic sheeting and then rubber mats over the top of it. Rolled-up towels can be placed around the edge of the mat to increase its water tightness.

Some parking lots drain through openings in the side of the curbs called catch basins. Catch basins can be sealed off with a sheet of heavy plastic topped with sandbags or other weights. Again, be sure the seal is tight before you start washing cars.

If the car wash site drains into the street and then into the storm drain, be aware that sealing storm drains in the street is not allowed. It can create a traffic hazard and also endanger those running the pump. You must use a catch basin on private property with the owner's permission.

Where do I get a sump pump?

Sump pumps are available at equipment rental stores for $15 - $20 per day. (They are commonly used to remove water from basements.) Or perhaps someone in your group has a pump that they would be willing to lend.

Is any other equipment necessary?

You will need a hose to carry water from the pump to either the sanitary sewer clean-out or the vegetated area. An extension cord will probably be needed along with a source of electricity. A broom may also be handy to sweep water towards the pump or to spread the water out so it will evaporate.

Does the pump need to be turned on all the time?

No. Some pumps will automatically turn on when the water level reaches a certain depth. Otherwise, someone has to be responsible to turn the pump on and off as water accumulates and is pumped away. A pump that is left running without water flowing through it to cool the motor can overheat and be damaged.

Once the car wash is over can soap residue harm creeks?

Yes, rain can wash the soap into the storm drain system where it can then pollute creeks. It is a good idea at the end of the car wash, while the storm drain seals are still in place, to thoroughly rinse down the wash area and properly dispose of the rinse water.

This all sounds pretty complicated. How can I be sure that our car wash is set up properly?

County of Sonoma staff is available to answer your questions and even tour the site with you. We can offer suggestions and help you determine the best way to keep wash water out of the storm drain system. Call the Storm Water Section at (707) 565-1900 for assistance.