Sediment overflows a poorly maintained silt fence at a construction site in Baldwin County.

Stormwater runoff is a major threat to our streams, rivers, and Bay. As development has taken place in Mobile over the years we have paved over absorbent parts of the landscape. This has caused a dramatic decrease in surfaces that allow water to infiltrate. 

Impervious surfaces such as parking lots, roads, and buildings, keep water from soaking into the ground and instead cause it to runoff over the surface. Pollutants accumulate on these impervious surfaces and are forced into storm drains and water bodies during rain events. This stormwater runoff causes increased concentrations of pollutants, higher rates of erosion, and faster more dangerous flows. 

Sources of urban runoff


Dead Zone in Gulf of Mexico July 28 - Aug 3, 2015 — areas in red to deep red have very little dissolved oxygen. (Data: Nancy Rabalais, LUMCON; R Eugene Turner, LSU. Credit: NOAA)

Many people don't realize that their own home can be a significant source of pollutants in stormwater runoff. Improperly fertilizing lawns, pet waste, soaps and detergents containing phosphates, and pesticides applied inconsistently with instructions on the label all contribute pollutants to stormwater runoff.

Fertilizer and pet waste are major contributors to excessive nutrient loads in our waterbodies. When nutrient concentrations become elevated it exacerbates a natural phenomena known as eutrophication.

Eutrophication is a condition where massive algal blooms are spawned by excess nutrients in water bodies. When the algae die off bacteria that breakdown the algae rapidly consume the oxygen in the water. This leads to dangerously low oxygen levels that can cause fish kills and other harmful effects in the aquatic environment.

After a rainstorm an oil sheen forms on a parking lot in Baldwin County where a car was leaking oil.

Eutrophication occurs naturally but the addition of nutrients by humans accelerates the rate at which it occurs and the severity of occurrences. The dead zone caused by eutrophication in the Gulf of Mexico was approximately the size of Connecticut and Rhode Island combined this summer according to the National Oceanographic and Atmospheric Administration (NOAA). When you consider that approximately 600 thousand people live in Mobile and Baldwin Counties and most of the rest of the state of Alabama drains into Mobile Bay it is obvious that this overlooked source is one of the largest generators of polluted urban runoff.

Another common source of pollutants is improper disposal of oil and oil leaks in cars. While it may seem like a small amount the cumulative effects of this across the Coastal Alabama area are quite large. Remember to keep all oil and gas in an area where they will not come into contact with stormwater and fix any oil leaks in your vehicle as soon as possible.

Commercial Sources

Our local businesses can be an important player in preventing polluted urban runoff. Large impervious areas such as parking lots increase surface flow and stormwater runoff. These parking lots are often littered with cigarette butts, trash, and other debris. This debris flows into our storm drains and from there directly into our streams and rivers. In addition, wastewater containing detergents, oil, leftover paint, or other substances are often improperly discharged directly into storm drains which is a major source of pollutants to our water bodies and Bay.

Construction Sources

Runoff filled with sediment rushes over insufficient silt fences at a problem site in Fairhope, Al

Often times construction projects require disturbance of large amounts of land for a long period of time. When this process is performed carefully using best management practices (BMP) the impact is minimized. However, hasty construction, lack of education, and limited oversight leads to projects with insufficient BMP's. This leads to stormwater runoff with large amounts of sediment in it.

This sediment is harmful to our economy, communities, and water bodies for multiple reasons. Economically it causes the waterways to need to be dredged more often than otherwise necessary. This dredging is expensive and can cause other harmful impacts to the environment, such as harming fisheries.

Many game fish hunt by sight and are not able to hunt effectively when sediment fills our rivers. Other species of fish require roughness in the bed of rivers or streams to lay their eggs. Sediment fills these spaces and can make it harder for these fish to spawn. Commercial fisheries and tourism generated by our phenomenal fishing are major drivers of the economy in Coastal Alabama; therefore, it is in our best interest to eliminate discharges of sediment from construction sites.

For this reason Mobile Baykeeper has created a program titled "Muddy Water Watch" that trains citizens to recognize deficient BMP's and how to work with Mobile Baykeeper, ADEM, and the site manager to have them corrected and protect our waterways.

Agricultural Sources

Farms are often unsuspecting source of polluted runoff. Much of rural Mobile and Baldwin county is agricultural land. Farmers rarely apply nutrients in such a manner that they will leave the farm in large quantities because they want their nutrients to be absorbed by their crop. Therefore they are incentivized to apply nutrients in a manner so that they will not leave their farm. Every pound of Nitrogen or Phosphorus leaving the farm is dollars lost to the farmer.

However, there are opportunities for improvement in many areas for our farmers. Many of these improvements can help their bottom line while also minimizing impacts to the environment. No-till agriculture is a method whereby a farmer may use cover crops, usually legumes, to control weeds in the offseason and add nutrients to the soil This means the field doesn't lay fallow and there is a crop on the land holding the soil in place and reducing erosion. As valuable as quality top soil is to farmers this is an important win for both the farmer and the environment. Farmers also may switch to pesticides that contain less harmful compounds. These safer pesticides reduce the amount of pollinators such as bees, butterflies, and birds that are harmed. Furthermore by restricting access of livestock to streams farmers are able to aid in reducing bacteria in our waterways.

 The Alabama Cooperative Extension Service (ACES) has great information on how farmers can improve productivity, lower costs, and protect the environment! 

Industrial Sources

Mobile County is a hub for industry. While these industries are a vital source of jobs in the area there must also be a respect for our amazing natural resources and the health of our communities. This requires industries that are good partners and do what is required of them to prevent pollution from entering our waterways. Industrial areas may contribute petroleum substances, metals, and other harmful pollutants to stormwater. These pollutants can be very dangerous since they can cause harm to the environment and our communities in very low concentrations. The severity of this threat means that it is crucial for industrial sources to minimize spills and discharges of pollutants and capture and treat all stormwater before it leaves their site to reduce pollutant loading in our waterways.

Mobile Baykeeper provides oversight and education to ensure reduction of stormwater caused pollution in Coastal Alabama. We work to ensure relevant entities know their legal requirements and are held accountable. We educate citizens on the deleterious effects of stormwater and how they can contribute to the solution. We research new best management practices and encourage their adoption by municipal, commercial, and industrial interests. Your membership is critical in giving us the ability to fund these vital missions and gives us the eyes and ears to know when and where we may have a problem.