San Luis Obispo County

San Luis Obispo County is regulated by the Central Coast Regional Water Quality Control Board, the same board that covers Santa Barbara and Monterey counties. It is a different regulator from the Los Angeles, Santa Ana and San Diego boards that govern property further south.

The Central Coast region carries a heavy agricultural discharge load alongside sensitive coastal receiving waters, and the board’s attention to what enters the storm drain system reflects that. For a commercial property owner the expectation is the same in substance as elsewhere in California: you are responsible for keeping pollutants out of the drain, and you should be able to show how.

We contain and recover wash water instead of letting it run, capture solids at the inlet, and log the method and disposal for every visit alongside dated photographs. Read what BMP (Best Management Practices), MS4 (municipal separate storm sewer system) and NPDES (National Pollutant Discharge Elimination System) require of a private property.

This is the dampest county we work in, and that single fact changes what cleaning here actually means.

Coastal fog through Morro Bay, Los Osos and Pismo Beach keeps surfaces wet for long stretches of the year. Buildings do not get dirty here so much as they get colonized. Algae, moss and lichen establish on north elevations, shaded walkways, roof tile and anything under a tree canopy, and they will keep returning as long as the moisture does.

The distinct problems in this county are:

• Algae, moss and lichen on shaded walkways, stucco, tile and roofing
• Slip risk on damp pedestrian surfaces, which is a liability issue before it is a cosmetic one
• Salt film on glass and painted metal along the coast
• Vineyard and agricultural dust inland around Paso Robles and Templeton

Organic growth is removed by chemistry, not by force. Pressure will strip the visible layer and leave the root structure in the surface, which is why the growth comes back faster after a hard wash than after a soft wash.

• Hotel & Resort Coastal and wine country hospitality where the exterior sets the rate
• Restaurant & Food-Service Patios, tasting room terraces and service areas
• Schools & Universities Campus walkways and building exteriors scheduled around term dates
• Commercial & Retail Property Downtown frontages and neighborhood centers
• Industrial & Manufacturing Processing and production facilities inland
• HOA & Multi-Residential Common areas and walkways on an annual program

Coverage runs from the North County vineyards down to the Five Cities.

• Why does moss come back faster after a hard pressure wash? Because pressure removes the visible growth but leaves the root structure embedded in the surface, and a stripped surface is more porous than it was. Treating the growth chemically kills what pressure leaves behind.
• Are damp walkways a liability concern? They should be. Algae on a shaded pedestrian surface is one of the more common slip hazards on commercial property in this county, and it is the reason many owners here move to a scheduled interval rather than reacting to complaints.
• Is this county under the same water board as Los Angeles? No. San Luis Obispo sits with the Central Coast Regional Water Quality Control Board, which is a separate regulator from the boards governing property to the south.
• When is the best time of year to clean here? Late spring through early autumn, when surfaces have a chance to dry and treatments have time to work. Winter work is possible but the fog cycle shortens how long a result holds.