I’m sure we've all been looking forward to the sunshine and the smell of spring after a rain shower. Clean and fresh. The rain washes away the dry and dirty, leaving the beauty of a refreshed landscape.
But, where did the rain go that carried away the dry and dirty? And what was so dirty that needed to be cleaned?
Rain runs down the gutter to the storm drain, or the Municipal Separate Storm Sewer System (MS4) to be exact. The storm sewer takes rain, snowmelt, and anything that floats down the gutter to the Big Blue River. This is often confused with the Sanitary Sewer which takes our home’s wastewater from the shower, laundry, dishwasher, and toilets to the wastewater treatment plant.
The two sewer systems are separate and function very differently. The Sanitary Sewer takes water to be cleaned and treated at the wastewater treatment plant. First, trash and non-organic materials, such as grit, are screened, collected and taken to the landfill for final disposal.
The screened wastewater flows into a primary clarifier, here organism treated organic solids are settled out of the water, producing a bio-solid (sludge) which can be composted and reused. Additional treatment is conducted by a Trickling Filter which utilizes random stacked plastic media which allows for the growth of organisms that decompose the organic material to an acceptable level.
The water is then disinfected using ultraviolet light that neutralizes any remaining pathogens before conveying the final flow to the Big Blue River.
The storm drainage system in Beatrice runs directly to the Big Blue River; it is not cleaned or treated.
Unlike wastewater, stormwater runoff is unpredictable and varies in volume, making it infeasible to treat with the same process as waste water. When rain, snowmelt, or the occasional sprinkler causes water to run down the gutter, it can pick up pollutants such as bacteria from pet waste, leaking oil and other fluids from our vehicles, heavy metals from brake pads, and phosphorus and nitrogen from fertilizers.
It can also transport large amounts of mud from active construction sites and disturbed ground. The stormwater and its pollutants deposit directly into our waterways. This type of pollution is called non-point source (NPS) pollution, since there’s no specific source, and it is the largest cause of impaired waterways in the United States.
As an example of this, the nitrogen and phosphorus from fertilizer are good for plants, in proper amounts. But consider what happens when the “little bit” that runs off the lawn to join the other “little bits” already in the storm sewer, Big Blue River, Missouri River, and Mississippi River. The excess nitrogen, phosphorus and other fertilizer nutrients in the water lead to large blooms of algae.
When the algae die and decompose, this dramatically reduces the amount of oxygen in the water creating hypoxic zones, more commonly called “dead zones,” in which organisms cannot survive. The Gulf of Mexico dead zone, where “little bits” of fertilizer run-off from across the country end up, was estimated to be 5,840 square miles in 2013, roughly the land size of Nebraska’s largest county, Cherry County.
Stormwater pollution is difficult to treat, but there are several easy ways to help prevent it. The main goal is to let only rain go down the drain. Pick up pet waste, throw litter in the trash can, keep the car in good condition by checking for leaks and regular maintenance, fertilize according to the directions and sweep any extra back onto the yard.
The list of suggestions is long but, the list of benefits is even longer.
The City of Beatrice has implemented a couple of programs in order to help with keeping our storm sewers clean. Currently, the City has two street sweepers which are owned and operated by the Street Department.
Through regular use, leaves, gravel and other pollutants are swept from the streets and disposed of properly at the landfill. Also, the Street Department has recently been utilizing an eco-friendly liquid spray on snowmelt product minimizing the amount of salt and gravel being placed on our roadways.
It all begins by being aware of stormwater – where it goes, what it picks up, and the simple ways to help keep it clean. So savor the scent of spring after a May shower and the knowledge of how to help keep our waterways just as clean and fresh.