Water Mitigation Garden

Overview

I Investigated whether or not agricultural runoff could be mitigated by using a homemade bio-filtration system to limit pollution and improve wild fish habitat. I wanted to discover if a simple bog type filtration system would help mitigate contaminates from agricultural farming before it reaches our rivers and streams. I chose this project because I became concerned about water pollution during the science experiment I performed last year. This Science fair project was about wild steelhead populations in Mendocino County and whether these fish were being affected by pollution. During this experiment the levels of contaminates found in the water samples collected were alarming. There were high levels of lead, sodium chloride, and sulfate, as well as elevated levels of many other contaminates. I wanted to see if there was a way to mitigate some of this pollution by creating a simple bio-filtration system to illustrate how this type of filter might improve water runoff from agricultural farming before it reaches our main rivers or tributaries. I first created a natural bio-filter by layering large gravel and a small amount of activated charcoal as a base layer, followed by a layer of organic soil without added fertilizer, and topped the model with a mixture of small gravel mixed with sand that was collected from a stream nearby my home. I collected a water sample from a culvert that directly drains into one of the main rivers in Mendocino County and tested it according to the directions provided by the 16 parameter test kit I purchased. After recording the data from this first test, I slowly poured the water sample into the bio-filter and turned on the pump. After allowing the water to cycle through the homemade filter the water was tested again; after 24 hrs, after 48 hrs, and after 5 days. I recorded my findings after each water sample test. There were unsafe levels of lead, nitrate, nitrite, and sodium chloride in the sample I collected. The sample I used in this experiment was well over the EPA’s acceptable levels for these contaminates with lead at 50 ppm, nitrate at 500 ppm, nitrite at 80 ppm and sodium chloride at 2000 ppm. These are dangerously high levels of the pollutants present in a water sample collected from a culvert that directly drains into the Eel River. After running the water sample through my bio-filter for 24 hrs the sample was tested again. At this time the contaminate levels were already mitigated to less than half of what the readings showed in the unfiltered sample. Lead content was 20 ppm, nitrate content was 100 ppm, nitrite content was 10 ppm, and sodium chloride levels were at 0 ppm. The water was tested for the third time just 48 hours after filling the filtration model and showed the lead content was 5 ppm, nitrate content was 25 ppm, nitrite content was 5 ppm, and sodium chloride levels were at 0 ppm. After 5 days of the water cycling through the filtration system all contamination levels were within a safe parameter according to the EPA’s acceptable levels. This final test showed lead at just 5 ppm, nitrates at 0 ppm, nitrites at 0 ppm, and sodium chloride at 0 ppm. In conclusion I discovered this type of filtration system is adequate for filtering out dangerous contaminates and making our rivers and streams safer for native fish and wildlife. My hypothesis was proven correct because even after only 24 hours the water was showing signs of purification beginning and by the 4th and final test the water sample was nearly drinkable. I think putting this type of filtration system in front of all farmland runoff culverts could greatly improve water quality for wild fish and animals alike. I believe this information is detrimental to our health and the health of our planet because water is the basis for all life. Understanding how we impact our natural world and learning about ways we can preserve our greatest natural resource is extremely important.

Competition history

• CSEF 2026 Earth & Environmental Sciences (Junior Division) · Entry J-08-31

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