Storm Drains: The Gateway to River and Stream Contamination

The storm drain.  A flat, plain, unnoticeable window to plethora of  man-made interconnecting  tunnels carrying precious liquid to the natural rivers and streams that provide our water supply.  That same storm drain also carries contaminants that pollute our rivers and streams making them almost hazardous to our health.  In order to grasp the gravity of the situation, lets break it down into numbers we can understand and move from there.

Lets say you’re washing your personal car with a garden hose (spray nozzle attached) in the comfort of your own driveway.  The garden hose pumps out 10 gallons of water per min on average.  8 of those minutes, the water is on and you are either rinsing the dirt off to start washing or rising the soap off after you’re done.  The 80 gallons of wash water you produced slowly makes it’s way down the driveway, into the gutter and eventually enters the storm drain where it’s forgotten about. That water contains soap, heavy metals such as copper off of break pads and oil and grease.  All of which you wouldn’t voluntarily take a nice swim in, right? That’s only 80 gallons you say…out of the millions of gallons that enter the storm drain every day, it will be diluted  and won’t do any harm.  You think that and so does everyone else.  That is the problem, everyone thinks their negligence won’t matter and it’s someone else’s problem.  Let’s extrapolate that now and think about every car rental, lease and sales company in the United States.  Too big of a number to handle? Okay, lets just take car rental companies.  There are approximately 21,498 car rental branches in the United States and if they’re at all successful, they’re washing at least 20 cars a day.   Now for the final calculation: 10 GPM x 8 Min/Car x 20 Cars/Day = 1600 gallons of wash water going down the storm drain per location x 21,498 = a whopping 34,396,800 gallons of wash water going down the storm drain every day in the United States of America.  If we thought about how many car rental locations are in Sonoma County and then thought about all that disgusting water going down the storm drain and eventually ending up in the Russian River, makes anyone with a sensible head on their shoulders think twice about taking a nice dip on a hot summer day.

Below is an example of the loading concentration of copper, lead and zinc in a typical storm drain and the numbers are in parts per billion.  As a comparison, a reasonable pollutant loading for copper would be about 500 parts per billion.

Storm Drain Samples - San Pablo cropped

There are two easy ways to reduce this insanely high about of contamination.  One is containment at the source and the other is storm drain filtration and/or plugging.  The Porta-Pad is the most cost effective way to contain wash water so it never gets to the storm drain.  Once contained, it can be safely pumped to a sanitary sewer drain.  Storm drain inserts filter a large majority of the water going through the storm drain but also has the ability to plug it up completely and act as a sump to pump water to a sanitary sewer drain.  We are not saying only use our technologies, we are simply saying, use something and stop this annihilation of our water supply!

Washing Cars with a Pressure Washer Washing Cars with a Garden Hose
3.5 GPM from PW 10 GPM from garden hose
5 Min/Car – Washing time 8 Min/Car – Washing time
20 Cars/Day 20 Cars/Day
                            350.00 Gallons per day used to wash cars                              1,600.00 Gallons per day used to wash cars
                      21,498.00 Car rental locations only *                            21,498.00 Car rental locations only *
    7,524,300.00 Gallons of water going to storm drain per day      34,396,800.00 Gallons of water going to storm drain per day
3.5 GPM from PW 10 GPM from garden hose
5 Min/Car – Washing time 8 Min/Car – Washing time
20 Cars/Day 20 Cars/Day
                            350.00 Gallons per day used to wash cars                              1,600.00 Gallons per day used to wash cars
                      10,749.00 Car rental locations only                            10,749.00 Car rental locations only
    3,762,150.00 Gallons of water going to storm drain per day      17,198,400.00 Gallons of water going to storm drain per day
Gallons of water going to the storm drain per day
(Based on 1/2 of locations using a pressure washer)
     20,960,550.00
* Data taken from 2014 U.S. Car Rental Market, Fact Book 2015 Auto Rental News