Long time ago, 1997, I have made a first model which estimate the potential contamination from dairy farm to groundwater and nearby water wells. I have been using Hydrus 1D, MODFLOW 96 and MT3D and this coupling pass results from on program to another. It was easily shown that there is high potential to cont
aminate nearby water well, although the thickness of vadose zone was about 5 meters and distance to water well about 1 km.
After that, that project was repeated in many countries, sometimes making it a bit more sophisticated, sometimes not, but the point was the same.
Unfortunately, the groundwater contamination from agriculture industrial operation become wide spread in every part of the world.
One of the remediation technologies for this kind of contamination (NO3 in groundwater from agriculture production) that can be helpful is to use groundwater already contaminated with nitrates (NO3) for irrigation (Addressing Nitrate in California’s Drinking Water, 2012), and then the crops will take care of the NO3 remediation and will purified water will be returned to groundwater.
The reason that other remediation techniques are not effective is that plume of NO3, which contaminated aquifer, has a large extent and any other remediation techniques (usually developed for point sources) would be cost ineffective.
While working a lot in agriculture sector in Europe and US I was exposed to different software which optimize nutrients for crops. Too much or too little is not good for crop yield and farmers want to deliver the right amount of nutrients (N, P, K) to maximize the yield.
In some agriculture fertilization software (ex. Smart Fertilizer) there is an option for taking account the water characteristic and quantity we irrigate crops and its NO3 concentration and calculate how much NO3 will be taken by crops and how much will be left in irrigation water on its way down to groundwater.
Now I am getting to the point, by using integrated approach, agriculture software for crops (Smart Fertilizer), vadose zone and groundwater flow and transport simulation (MODFLOW UZF package ex.) good estimates can be achieved to estimate rate and time needed for remediation of large volume of aquifer contaminated with NO3.
You can message me for more details at support@advancedgwt.com and if there will be enough interest I can make a webinar on this topic.