water quality monitoring Archives - San Diego Coastkeeper

Why We Spend Our Saturdays Collecting Water Samples

Written by Meredith Meyers

wqm-saturdayWe have laws in place to limit industrial pollution and ensure that our water can support all of its uses, from swimming and fishing to hosting endangered wildlife. But without enforcement, these regulations cannot keep our water healthy. That’s where San Diego Coastkeeper comes in.

Urban runoff is the single biggest threat to water quality in San Diego. During the dry season, pollutants build up on hard surfaces like roads and parking lots. When it rains, stormwater pushes the accumulated pollutants into our storm drains. In San Diego, like most of California, our storm drains generally do not connect to wastewater treatment plants, so everything flows untreated into our waters. Pollutants created by industries, like metals and oils, are especially serious because they can be toxic in very low concentrations.

The Clean Water Act is a federal law that lays out the legal requirement for protecting, maintaining and improving the health of our water bodies. It is our most powerful tool for making sure San Diego’s water is healthy because it mandates that all states identify creeks, rivers and shorelines that are severely impaired by pollution.

Unfortunately, state and local regulators often don’t review water quality reports or conduct monitoring to make sure that industries are meeting Clean Water Act standards. San Diego Coastkeeper steps up to make sure that industries are doing everything they can to reduce pollution to our rivers and beaches. We review water quality reports, but that’s only the first step.

San Diego’s local government agencies have limited resources and they monitor infrequently, providing only a snapshot of water quality. To solve this problem, San Diego Coastkeeper also conducts our own monitoring to ensure compliance of clean water rules. We collect and analyze water samples from nine out of 11 watersheds in San Diego County every month. To ensure that our data meets the highest quality standards possible, Coastkeeper follows a rigorous quality assurance and control plan and standard operating procedures that have been approved by our state regulatory agencies. Sounds like a big job, right? That’s why we train over 100 volunteers each year and rely on them to help.

When we find polluting facilities, we use the Clean Water Act to bring them into compliance through enforcement actions. Our goal is to force industry operators to install and use best management practices that will meaningfully reduce pollutants in our waterways.

Want to see what kind of report card your local watershed is getting? Click here to explore a map of the most recent data we have for locations from Otay to Carlsbad.

Published in Urban Runoff

Top Five Things We’ve Learned from Water Quality Monitoring

Written by Meredith Meyers

wqm_volunteer_take_samples-1We may not think about it every day, but we all live in a watershed. A watershed is the area of land that catches all the rain and snow, which collects into a marsh, stream, river, lake or groundwater. What we do on the land affects the quality of water for all communities living downstream. So what does this mean? It means our rivers and streams are the report card for a watershed’s health.

San Diego Coastkeeper has been monitoring local waterways since 2000. We assess watershed health on a monthly basis by measuring nutrients, bacteria, and basic water chemistry (temperature, pH, dissolved oxygen, etc). We monitor fixed sites in nine of San Diego County’s eleven coastal draining watersheds and use our data to assign water quality scores to each of our sites and annual watershed health reports. Most importantly (perhaps) is that we share these scores with the public by updating water quality information monthly on our website.

San Diego Coastkeeper is the only countywide, routine water quality monitoring program in San Diego, and we’re the largest volunteer-led effort of its kind in the state. We train over 100 volunteers each year to collect water quality data, and by analyzing the data that volunteers collect, we identify polluted waters and reduce sources of pollution.

We’ve learned  a thing or two after 16 years of monitoring San Diego County’s water quality. These are our top five lessons learned.

5.) Urbanization is linked to poor water quality. 
Want an example? See how fertilizers alone hurt our water.

 4.) Nitrates are especially high in Escondido Creek.
At high levels, nitrates can be toxic to animals and humans. The best way you can prevent nitrate pollution in our waters is to limit the use of chemical fertilizers in your yard, or better yet rip up your grass and plant native plants that don’t need fertilizers.

3.) Bacteria levels are really high after a rain event.
Here are ten tactics to keep bacteria out of our waters by preventing polluted runoff.

2.) Drought affects water quality, not just quality.
Ambient measurements help us determine when poor water quality is harming the flora and fauna of our waters.

1.) We could not do this without our extraordinary volunteers.
Each month, 40 – 45 San Diego residents volunteer their Saturday to collect field samples and process them in the lab. During 2014 alone, 194 volunteers gave a total of 1,888 hours.

Water Quality in 2015 – How Drought Causes Worse Water Quality

Written by Meredith Meyers

Water Quality 2015

San Diego County Watershed Scores - 2015Water Quality Index Score Explanation

Each month, the trained volunteer scientists on our Water Quality Monitoring team collect water samples from nine of San Diego County’s 11 coastal watersheds. We measure and test the samples in our lab and analyze the data to build an ongoing picture of our county’s water quality, uncover sources of pollution and inform better decision making to protect and restore San Diego County’s fishable, swimmable, drinkable water.

Here are the results of the data collected throughout 2015 in our 2015 Water Quality Report.

Our Fourth Consecutive Year of Drought Continues To Worsen Water Quality

Jeremy hands off to Steven - Adrian KinnaneIn 2015, all nine of the watersheds tested as Fair, Marginal or Poor on San Diego Coastkeeper’s Water Quality Index scoring system, all earning the same abnormally low scores as 2014.

Poor water quality puts significant stress on the vital rivers and streams that we rely upon for everything from flood control and natural filtration of toxins to wildlife preservation. Since our watersheds drain to the Pacific Ocean, these inland water quality issues also make our precious, economy-powering coastline less safe to swim and fish.

Very low water levels as a result of our fourth consecutive year of drought are partially to blame for the continued poor water quality scores. In 2015, we had more sites with water levels so low they were too dry to collect samples than any other year in our recent history.

Our 2015 data reveal low dissolved oxygen concentrations in 38 percent of samples and unhealthy levels of fecal indicator bacteria in 59 percent of samples, both common results of drought conditions. Urban runoff, sewage and industrial pollution are also likely significant contributors to the poor water quality.

Fecal Indicator Bacteria: Our Biggest Concern

Volunteers_Testing_SLR-090Our water scientists use E. Coli and Enterococcus bacteria as indicators of water contamination by fecal material (animal poop or human sewage). These indicator bacteria are often present in some amount in our inland water, but high levels of them often indicate the presence of dangerous viruses and pathogens that can make you sick.

Over three quarters of our water samples in 2015 contained unsafe levels of fecal indicator bacteria. This means that our rivers and streams are carrying pollutants to the ocean that cause health problems like staph infections, ear aches, stomach issues, rashes, eye infections, and cysts — just to name a few.

When we collected samples 48 hours after a rainstorm in May 2015, every watershed but one exceeded unhealthy levels of Enterococcus. This is why the County’s Department of Environmental Health closes the beaches countywide after it rains — water quality is so poor that it becomes unsafe to swim.

This data also raises a question that we need more research to answer: “Is the drought reducing water levels so much that shallow, slow-moving and warm streams allow Enterococcus and E. coli to stick around much longer?” As in 2014, many of our testing sites in 2015 were so dry that we could not gather samples. We’re curious to explore this question with further research.

Low Dissolved Oxygen Levels Make It Hard For Aquatic Wildlife To Breathe

lab volunteerOur 2015 data revealed low dissolved oxygen concentrations in 38 percent of samples. This means our underwater wildlife is in significant distress. We can partially blame drought conditions for this problem, but urban runoff pollution is also a likely contributor.

When rain washes nutrient pollutants, like agricultural and lawn fertilizers, down storm drains and into our watersheds, it supercharges plant growth in our rivers and streams just like it does to grass in our yards. But this growth triggers a nasty chain reaction called eutrophication. Nutrient pollution can fuel massive, unnatural blooms of algae on the water’s surface that grow so big they block the sun from reaching plants below the water. When these plants die from lack of sunlight all at once, they begin to rot all at once too, producing an unnatural amount of bacteria that use up the dissolved oxygen that other wildlife depend on to breath. This puts stress on or kills our underwater wildlife.

Volunteer-Powered Data

Water-Quality-Monitor-1Our 194 volunteer Water Quality Monitors gave a collective 1,808 hours to collect this important data. In 2015, we trained 74 new Water Quality Monitors and plan to triple our volunteer force by 2018.

Our Water Quality Monitoring program is the largest of its kind in the state and is one of San Diego Coastkeeper’s most powerful tools in protecting and restoring our water. The work of our passionate volunteers generates the vital, scientifically sound data our government agencies can’t collect, allowing us to keep a vigilant watch over San Diego County’s water quality.

In 2011, our Water Quality Monitoring team discovered a 1.9-million sewage spill upstream of the Los Peñasquitos Lagoon. The program provided authorities with the only available baseline water quality data and tracked the lagoon’s recovery. Water Quality Monitor testimony then contributed to a $12 million investment in basic sewage infrastructure, ending San Diego’s “sewage-spill-a-day” reputation.

Click below to check your watershed’s report card.

Read the specific water quality scores for each of the nine tested watersheds below.

San Diego River   tijuana   Otay

Pueblo   San Dieguito   San Luis Rey

sweetwater   Peñasquitos   Carlsbad


Water Quality 2015: Carlsbad Watershed

Written by Meredith Meyers

Water Quality 2015 - Carlsbad

Water Quality Index Score: 66, Fair

Carlsbad Polar 2015To no surprise, our 2015 data showed that:

  • Nitrate continues to be  consistently high in upper Escondido Creek. Every single sample collected from our three upper Escondido Creek sites was above the basin plan standard.
  • Fecal indicator bacteria counts were also high.

In fact, the ten samples with the highest nitrate concentrations collected anywhere in San Diego County in 2015 came from Escondido Creek. Because of this, our volunteers report seeing a lot of algae growth in the water.

We’re not surprised because nitrate always measures high in Escondido Creek, but we’re interested in learning why this consistently happens. Recently, we inquired with the City of Escondido, and representatives say it comes from groundwater and the legacy pollution from the agriculture industry. Thankfully, our longtime volunteer and board member, Taya Lazootin, is running a research project to examine nitrate in Escondido Creek to figure out what’s happening. We’ve also implemented stormwater monitoring in the upper Escondido Creek sites to investigate the pollution issues here.

Fun fact: Our volunteers in Carlsbad are some of our longest serving volunteers. Many of them have been water quality monitors for over 5 years.

Water Quality Index Score Explanation

Water Quality 2015: San Luis Rey Watershed

Written by Meredith Meyers

Water Quality 2015 - san luis rey

Water Quality Index Score: 80, Fair

San Luis Rey Polar 2015Of the nine watersheds we measure in our water quality monitoring program, San Luis Rey had the best water quality index score in 2015.  But at 79.9 (roughly a B- or C+) it’s not exactly a stellar grade.  

We tracked two parameters of concern in San Luis Rey Watershed:

  • Turbidity: Two-thirds of the turbidity samples exceeded healthy standards
  • Levels of pH: Over half of the pH samples collected exceeded healthy standards

Turbidity and Tidal Wetlands

Turbidity refers to the cloudiness or haziness of water caused by many small particles generally invisible to the naked eye, similar to smoke in air. Small particles, such as sediment or organic material, in the water make it appear cloudy.   When turbidity is high, it’s harder for light to reach the ground, affecting the growth of plants. As well, pollutants like metals and bacteria can hitch a ride down our watersheds in the spaces between these particles.

We especially care about turbidity in the San Luis River because it contains a tidal wetland, a habitat where fresh water meets coastal salt water. Tidal wetlands are vital habitats for species like mullet fish and birds that depend upon a consistent balance of fresh and salt water. If unnatural amounts of sediments build up in this area, they can block salt water from entering the area and disrupt the balance of this critical habitat.

Water Quality Index Score Explanation

Water Quality 2015: San Diego Watershed

Written by Meredith Meyers

Water Quality 2015 - sd (1)

Water Quality Index Score: 62, Marginal

San Diego Polar 2015

The San Diego River had another bad year.

Key data takeaways include:

  • Commonly high levels of phosphorus and ammonia
  • Dissolved oxygen at the Fashion Valley site continued to be very low – even in the winter when it is usually higher
  • Repeated reports from our volunteers noting excessive amounts of algae and duckweed
  • Volunteers repeatedly reported lots of trash

Four Symptoms of One Phenomenon: Urban Runoff

All four of these bullet points are related, indicating a chain reaction likely triggered by urban runoff. Rain washes pollutants from our urban areas down our storm drains and into our watersheds. These pollutants include trash, like that reported by volunteers as well as fertilizers we use for our lawns and landscaping. These fertilizers contribute to high levels of phosphorous and ammonia which supercharge plant growth. In the San Diego River’s case, this meant large blooms of algae and duckweed. This growth blocks sunlight from reaching plants beneath the water, causing them to die and begin to rot all at once. The rotting produces an unnatural surge of bacteria that use up the dissolved oxygen that aquatic wildlife depend on to breathe. This phenomenon was so prevalent in the San Diego River that for two consecutive months, we measured dissolved oxygen at deadly low levels (called anoxic, <0.5 mg/L).

The San Diego River is also an example of how lower water levels caused by the drought affect our water quality. We estimate that the San Diego River’s low water levels in 2015, contributed to slower water flow and warmer temperatures. This likely exacerbated the river’s problems by creating a better breeding ground for explosive algae growth.

Water Quality Index Score Explanation


Water Quality 2015: Tijuana Watershed

Written by Meredith Meyers

Water Quality 2015 - tj (1)

Water Quality Index Score: 14, Poor

Tijuana Polar 2015Since we can only sample the Tijuana watershed when water levels are high after a recent rain, we were only able to sample the watershed three times this year.

The Tijuana-based sewage treatment plant handles and purifies 50 million gallons of river water every day, but it can’t handle wet weather flows. When it rains, the operators divert the river flow without treatment, and that’s when we can sample the river. This is also why Imperial Beach beaches are frequently closed during the winter.

Our only sample in 2015 followed a massive rain event in December. That sample showed:

  • Bacteria levels were extremely high – even diluting the sample 100 fold, the concentrations were still higher than our test kits can measure
  • Ammonia and phosphorus levels were off the charts
  • Volunteers find the water looking murky and comment on its extreme odor

This watershed requires a lot of cross-border collaboration to truly understand and solve the interconnected water quality issues. We’re looking for passionate volunteers to get trained in water quality monitoring so they can champion efforts in this challenging watershed. What are you waiting for? Sign up to get trained!

Water Quality Index Score Explanation

Water Quality 2015: Otay Watershed

Written by Meredith Meyers

Water Quality 2015 - Otay

Water Quality Index Score: 57, Marginal

Otay Polar 2015Over the course of 2015, the Otay Watershed remained the most consistent watershed in the county. Unfortunately, the water quality was consistently bad.

In better news, we loved hearing that Water Quality Monitors in this watershed also consistently spotted dragonflies, crawfish and herons while sampling.

Stormwater Detective Work

To further investigate these troubling water quality problems, we launched a stormwater sampling program in 2015 to supplement our regular testing of the Otay watershed. Our stormwater sampling program enlists a special team of volunteer Water Quality Monitors to drop what they’re doing as soon as a storm hits to collect stormwater samples at specific sites of interest.

During storms, as the rainwater runs off our lawns, driveways and streets, it carries pollutants like metals, bacteria and sediment into our rivers, lagoons and ocean. With our stormwater monitoring program, we hope to better understand where and how much pollution is entering our waterways during rainstorms.  This information can then be used in efforts to clean stormwater before it has a chance to harm our watersheds.   

Water Quality Index Score Explanation

Water Quality 2015: Pueblo Watershed

Written by Meredith Meyers

Water Quality 2015 - Dieguito (1)

Water Quality Index Score: 56, Marginal

Pueblo Polar 2015A few key takeaways from our Pueblo Watershed data:

As this watershed is home to Chollas Creek, one of San Diego’s most urban rivers, these results aren’t unexpected. The high phosphorous and ammonia levels in this watershed are a common result of urban runoff, when rain washes pollutants, like lawn fertilizers and pesticides, down our storm drains and into our rivers and streams.

This creek is also infamous for drying up, so our dataset is missing many samples throughout the year. In fact, more sites went dry this year than any other year in Coastkeeper’s recent sampling history here. All signs point toward poorer water quality than shown with the samples that we could collect. With more flow and more samples, this watershed probably would have earned a Poor Water Quality Index Score.

Water Quality Index Score Explanation

Water Quality 2015: San Dieguito Watershed

Written by Meredith Meyers

Water Quality 2015 - Dieguito

Water Quality Index Score: 76, Fair

San Diegito Polar 2015Our data in San Dieguito Watershed show:

Ammonia and Phosphorous

These are nutrients people add to farms, lawns and gardens to encourage robust and healthy plant growth. In our water, however, extra nutrients are harmful pollution. When rain washes these nutrients down storm drains and into our watersheds, it triggers an unhealthy chain reaction called eutrophication. Nutrient pollution can fuel massive, unnatural blooms of algae on the water’s surface that grow so big they block the sun from reaching plants below the water. When these plants die from lack of sunlight all at once, they begin to rot all at once too, producing an unnatural amount of bacteria that use up the dissolved oxygen that other wildlife depend on to breath. This puts stress on or kills our underwater wildlife.

Nutrient pollution is a huge concern for this waterway because our volunteers spotted lots of wildlife including blue herons, hummingbirds, ducks, bull frogs, carp, bass, crayfish, turtles, clams, crawfish and many insects.

Marine Debris

Volunteers noted this watershed was filled with trash including fishing gear, golf balls, old tarps, knitting needles, clothing, irrigation piping, and beer bottles.

Water Quality Index Score Explanation