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Phosphorus Control in Dane County

Fertilizers normally contain a mix of nutrients, including nitrogen, phosphorus and potassium. Rainwater runoff from lawns treated with fertilizers flows to storm drainage systems and into the lakes where the phosphorus from many sources causes excessive algae growth, and decreases water clarity, often turning lakes green. Decaying algae also depletes oxygen in the water, so that fish can no longer thrive.

In order to improve lake water quality by reducing phosphorus runoff, on April 15, 2004, the Dane County Board adopted Ch. 80 of the Dane County Code of Ordinances, "Establishing Regulations for Lawn Fertilizer Application and Sale (pdf)." The County Executive subsequently signed the ordinance into law.

The ordinance went into effect in January 2005 in every town, village and city in Dane County. Beginning May 1, 2004, signs containing the ordinance requirements and the effects of phosphorus on Dane County waters must be prominently displayed where lawn fertilizers are sold. Click here to download a copy of a sign developed by the Dane County Lakes and Watershed Commission for retailers to post.

The ordinance:

  • Prohibits use of phosphorus-containing lawn fertilizers, unless a soil test shows that phosphorus is necessary.
  • Prohibits retail display of phosphorus-containing lawn fertilizers.
  • Makes clear that golf courses, farmstead lawns, and commercial applications to lawns are subject to the ordinance.
  • Exempts newly-established turf and lawns during their first growing season.
  • Exempts fertilizers intended primarily for garden and indoor plant application, and fertilizers applied to trees and shrubs and for agricultural uses.
  • Clarifies that yard waste compost and biosolids intended primarily as soil amendments are exempt from the ordinance.
  • Specifies penalties for ordinance violations; with higher penalties for commercial/retail violations.
  • Specifies that the Environmental Health Section of the Public Health Division, Dane County Department of Human Services, will enforce the ordinance.

Federal Courts Uphold Dane County Ordinance

Industry challenges to Dane County's ordinance have been rejected by federal courts. Follow this link to read the June 13, 2005 decision of the U.S. District Court for the Western District of Wisconsin. Follow this link to read the December 23, 2005 decision of the U.S. Court of Appeals for the Seventh Circuit.

Ordinance Development

In July 2003, County Executive Falk asked the Lakes and Watershed Commission to develop, introduce and work with the County Board to pass an ordinance limiting phosphorus in lawn fertilizers in order to improve lake water quality.

The Lakes & Watershed Commission sought and reviewed extensive public input during ordinance development. A total of 245 comments were received: from the December 11, 2003 public hearing and from online, written, email and phone contacts. The Commission made a number of adjustments to the ordinance based on public input. The Commission voted to delay the effective date until January 2005 to accommodate retailers' concerns about inventory already ordered. On January 20, 2004 the Commission voted unanimously to recommend passage of the ordinance they developed and revised, and the ordinance was introduced to the Dane County Board on January 22, 2004. The County Board passed this ordinance on April 15, 2004.

Expert input used in ordinance development, and statements released by the Lakes and Watershed Commission are found below.

Related Resources



Yahara Waterways Trail Guide The Yahara Waterways Water Trail Guide is a great resource for exploring our area waters.