We have had many confused residents and builders approach us to help them understand how to meet the City of Encinitas requirement for new construction to include a greywater stubout for all greywater fixtures.  Interestingly, the City of Encinitas first instituted this requirement around 2015. Although there was initially a learning curve for builders, city planners, and inspectors, the City of Encinitas has actively been working on improving education and consistent enforcement. Over the past eight years, dozens of systems have been successfully installed in Encinitas, and many exemptions have been granted based on site-specific conditions.

It is extremely progressive for the City to require new buildings to include greywater stubouts.  They are only one of a couple juristictions in the State of California to do so, and certainly the only jurisdiction in the County of San Diego to do so.  We are excited for the potential for our future cities to be tapping into this wonderful resource as a standard practice.

However, there is a lot to learn about how to “require” greywater stubouts with the hopes it will result in widespread greywater use.  Since greywater integrates wastewater and landscaping, and most planners are not well versed in BOTH wastewater and landscaping, there tends to be a lot of requirements that suit either wastewater or landscaping but not both.

What Are the Requirements?

That said, let’s dive into what we KNOW about the requirements for including a greywater stubout for plan submittal.

1.  It is only required to provide a greywater stubout for a new house.  NOT an ADU or an addition.
2. All fixtures that are considered greywater must be plumbed for greywater.  This includes lav sinks, showers, baths, laundry, and sauna/steam rooms.  Also sometimes outdoor showers and BBQ sinks.  Toilets and Kitchen Sinks are considered blackwater, NOT greywater.
3. You must include a diverter valve in your plan                   
4. You are required to submit an plumbing isometric showing
   • all fixtures connected to greywater lines
   • all fixtures connected to blackwater lines
   • plumbing pipe size and type (ie, ABS or PVC) according to plumbing code – how many fixtures you are collecting from
   • location of diverter valve
5. Things you are not required to include at this stage:
   • You are not required to include greywater plans
   • You are not required to include any electrical associated with the future greywater system (unless you submit greywater plans)
   • You are not required to consider how your landscaping will tie into a greywater system
6. There are fee waivers for greywater systems in place but it is unclear what they pertain to since the documentation in different places refers to either retrofits to existing structures OR greywater systems that do not impact existing mechanical or other building systems.

Considerations for your future greywater system

So let’s explore what you may want to think about as you consider your stubout and whether or not to include a greywater system in your plans.

How to implement greywater stubouts

Greywater stubouts can be implemented in a couple different ways.  You can dual plumb the whole house so all greywater goes to one line that parallels the blackwater line and connects outside the building after the 3 – way diverter valve is installed.  CAUTION:  this is a great, simple way to implement a greywater stubout, however managing ALL the water from the house at a single point almost always necessitates using a pump to effectively distribute the greywater to your landscape effectively.  This may be necessary either way depending on your landscape and your lot design.  Source: https://oasisdesign.net/greywater/

Alternatively, you can plumb individual fixtures to individual landscape areas.  Especially if the lot isn’t too large and there aren’t too many fixtures, this may be a good solution for creating low cost, gravity fed greywater systems.  This will require some creative landscaping to create areas that can handle flood irrigation and plantings that will be able to tap into it.   It also means you will need to carefully plan the plantings around the actual water useage to ensure the plants get enough and not too much water.   This strategy would require creative plumbing and placement of fixtures.  Running each bathroom (lav sink, shower, bath) to a nearby area of landscaping and tying the line back to the sewer after the greywater valve may mean a deeper sewer lateral since you will have more fall as the greywater pipe goes out to the landscape and back to the sewer lateral.

Depth of the stubout

Other things to think about and encourage your contractor to think about on your behalf is the depth of this stubout.  We notice that most contractors like to drop the waste lines below the foundation and then the lines drop further and further as they collect all the fixtures so that by the time the waste pipe exits the buildings it’s 20″ – 30″ below grade.   This means that to get water out to your landscape, you probably will need a pretty deep surge tank (48″ – 60″), and definitely a pump to distribute the water, and trenching and running pipes at this depth is not fun!  Especially post construction.

Location of the stubout

If you don’t pay attention to the location of this stubout it could be located under a poured concrete pathway or other paved area.  It’s nice to prelocate it in a utility or garden area even if you have to run in a line that is not super efficient for the sewer lateral (another reason to encourage your contractors to keep the line as high as possible before it exits the building)

Surge Tanks and Pumps

If you need a surge tank, you will want to plan ahead for sure since Plumbing Code requires surge tanks to have an overflow that ties back into the sewer lateral.  If you come in post construction to tie into your sewer lateral toward the end of the line, you are going to have a challenging time!

If you know you will need  pump, you will need to acount for an extra dedicated circuit, probably 20A and probably 120V will do, out to the area where the pump will be.

Please note, grewyater does not get stored.  It must be distributed within 24 hours, so any surge tank is just that – for surging water to get imediately pumped to the landscape.

Types of Greywater Systems and Landscaping

On the final note of landscaping, it is important that you understand when you make your landscape plan, if you are using greywater, which plants will work with greywater and which don’t.  Also the variety of cost associate with different styles of greywater distribution might help you decide on a style of landscape that will lend itself to a simpler system.  We like to think of greywater fitting into roughly 3 different categories (not including laundry to landscape):

1. gravity greywater
   • flood irrigation – no pumps
   • could be $1500 of extra plumbing during construction to $3500 for a retrofit) including greywater valve
   • works with smaller areas of landscape (still can do small orchard systems) that can handle a large volume of water distributed in a relatively small area via flood irrigation
2. simple pumped greywater systems
   • includes surge tank, and pump
   • (Could be $3500-$5500 just for the surge tank/pump/distribution/electrical setup not including the work done during construction to bring the greywater stubout and electrical to the location)
   • Useful for large landscapes but requires strategic placement of plantings around depressions(basins) that will collect flood irrigation regularly
3. pumped to drip greywater
   • includes surge tank and pump with post pump filtration to specially designed drip irrigation.
   • This is the most costly and maintenance heavy type of greywater system. (Could be $4500-$8500 for the surge tank/pump/distribution/electrical/controls not including the work done to bring the greywater stubout and electrical to location).
   • Allows for more traditional landscape

Fortunately, we have successfully permitted dozens of greywater systems throughout the county and we know the ins and outs of not only how to interpret the code but also how to effectively implement greywater systems that irrigate your landscape.  We will update you as the code in Encinitas becomes more clear or changes.  Sign up for a consultation with us today if you want to account for your greywater stubout and design your greywater system!