The grass can be grown with minimal runoff. Unfortunately everyone tries to follow the recommendations of sports fields/golf courses in their yards. All their methods are designed to meet the requirements of the sport, not the needs of the grass.

Farmers in the Midwest are by far the worse offenders. They frontload their nitrogen application using anhydrous ammonia in the fall or early spring. The ammonia is converted to nitrate by bacterial activity. Part of it then runs off early in the season with snowmelt or rain (that's when the tile systems are usually draining water from the fields).

The solution is well known. Use of polymer coated slow release urea at planting or side dressing with straight urea at V4/V5. It's more expensive per lb apllied but it takes up to 50% less N applied to achieve the same result. Especially compared to fall applied anhydrous ammonia.

Combined with winter cover cropping nutrient runoff can be significantly mitigated.

It's a relatively easy fix but it costs more money... So the pollution keeps running off.