Environmental issues in the San Joaquin Valley facts for kids
The San Joaquin Valley in California is a big, flat area known for its farms. It stretches from the Tehachapi Mountains in the south to the Sacramento–San Joaquin River Delta in the north. This valley is also home to cities like Fresno and Bakersfield. Because of all the farming, factories, and busy roads like I-5 and CA-99, the valley faces some important environmental challenges.
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Water Pollution
Water pollution is a big problem in the San Joaquin Valley. It affects both the rivers and the water underground.
River Water Pollution
The San Joaquin River and its smaller streams flow through the entire valley. The water in these rivers gets dirty from farm runoff, animal farms, and city waste. Things like selenium, fluoride, and nitrates have been found in the water. Selenium comes from natural soils on the west side of the valley. The river also has too much salt because of irrigation, which washes minerals off the land.
Old, unused mines can also add harmful chemicals to the river. For example, the Atlas Asbestos Mine and the New Idria Mercury Mine are places that need special cleanup. The Fresno Municipal Sanitary Landfill is another such site that has been cleaned for many years.
A famous example of water pollution happened at Kesterson Reservoir in the 1980s. At first, many animals and plants lived there. But by 1983, birds started to have serious deformities and even died. This was because of increasing levels of chemicals and toxins. Soon, most fish died, and too much algae grew in the polluted water.
Underground Water Pollution
The water underground, called groundwater, can also get polluted. In Fresno, the groundwater is close to the surface, making it easy for pollution from farms and runoff to seep in.
In 2001, an environmental group said Fresno's water quality was poor. The city tests and treats the water it pumps from the ground to make sure it is safe to drink. Local groups also use rainwater and river water to refill the underground water supplies. This helps keep the water clean.
Around 2016, some people in Fresno saw their tap water turn red, brown, or yellow. This made them worry if the water was safe. Experts checked the water and said it met safety standards. They found it was not as bad as other famous water problems. A lawsuit was filed by some residents, but a judge later dismissed it.
Air Pollution
The San Joaquin Valley has some of the worst air pollution in the United States.
The air often has high levels of smog (a type of gas called Ozone) and tiny particles (called PM2.5). These particles are like very small bits of dust and soot. In 2022, a report showed that three cities in the valley had the worst levels of these tiny particles. Only the Los Angeles area had worse smog.
The valley's unique shape makes air pollution worse. Mountains surround the valley floor, trapping the dirty air like a bowl. This causes pollution to build up.
This bad air quality leads to many people, especially school-age children, having asthma.
Efforts to Improve Air
The San Joaquin Valley Air Pollution Control District works to clean up the air. They have made plans to meet the rules of the Clean Air Act. These plans aim to reduce smog and tiny particles in the air.
Even with these efforts, the levels of smog and PM2.5 in the valley are often higher than national safety standards. The problems with tiny particles usually happen in the winter. Despite this, the air district continues to work on improving air quality for everyone.
Natural Disasters
The San Joaquin Valley can also be affected by natural events like droughts, earthquakes, and floods.
Drought
The San Joaquin Valley often experiences periods of drought. Drought means there is not enough rain. Since farmers need a lot of water for their crops, droughts cause big problems for them.
In recent years, Fresno has received much less rain than usual. This means small rivers have dried up. Less water is available for farms. Reservoirs, which store water, are also lower than they should be. Water is released from these reservoirs to make room for snowmelt and to provide water for southern California. This can make droughts even worse.
When rivers and reservoirs dry up, farmers pump more water from underground. This can quickly lower the water levels in the aquifers (underground water storage). When too much water is pumped out, the land can even start to sink. Fresno has seen its groundwater levels drop a lot over the years. The city is now trying to refill the underground water supplies and use other water sources to help.
Earthquakes
Many geologic faults run under the San Joaquin Valley. These faults can cause large earthquakes. Some of the biggest earthquakes recorded in the area include the 1857 Fort Tejon earthquake and the 1952 Kern County earthquake. A smaller one was the 1983 Coalinga earthquake.
Floods
The San Joaquin Valley has also experienced major floods. The Great Flood of 1862 covered the valley in water. Other floods happened in 1955 and 1964.
