NutrientNet User's Guide

Glossary of Terms


An account is a buyer and/or seller entity on NutrientNet. All accounts have a user login and have the ability to trade credits. The Pennsylvania Department of Environmental Protection retains the right to revoke the trading privileges of an account at any time.


A bid is an offer to buy credits posted to a marketplace. Bids must be placed on a specific marketplace posting. They have one or more water years associated with them.


A credit is the basic trading unit on NutrientNet. As defined by Pennsylvania Department of Environmental Protection, it is 'The unit of compliance that corresponds with a pound of reduction of nutrient or sediment as recognized by the Department which, when registered by the Department, may be used in a trade.".

Credits Needed Board

The Credits Needed Board is a bulletin board where accounts seeking credits to buy can post notices of credits needed. Potential sellers can respond to these notices by contact the buyer through the board.

Credit Reserve (DEP)

The DEP credit reserve is a quantity of credits set aside by the Department to address nutrient and sediment failures, uncertainty, and to provide liquidity in the market.


The Marketplace is where postings of credits for sale are listed, and buyers can place bids on these credits. Currently in NutrientNet, there are two marketplaces, the Nitrogen Marketplace and the Phosphorus Marketplace.


Nitrogen or Phosphorus


A posting is a grouping of credits available for sale on a marketplace. Postings have one or more water years associated with them. Postings must be made to a single marketplace and correspond to a single watershed.


Projects are activities or groups of activities that generate credits. Projects must be for a single watershed, chesapeake bay segment, county, source type (non-point or point) and account; however, they may contain a number of years and more than one nutrient.

Seller Reserve

The Seller Reserve is a credit reserve in the seller's account that can be used to manage the seller's credits. Credits that are in the seller's reserve are not available for posting to the marketplace until the are removed from the reserve. The seller reserve is primarily a credit management tool for the seller. In some cases, the seller may want to set credits aside, such as to hedge against uncertainties in projects that are not yet implemented.


A trade is a credit transaction between buyer and seller. In NutrientNet, a pending trade is created when a seller accepts a bid. When DEP approves a pending trade, it becomes a completed trade and credits are moved from the seller to the buyer account.

Water Year

October 1 through September 30. For example, water year 2007 is from October 1, 2007 through September 30, 2008.


The land area from which water drains into a particular stream or river. In NutrientNet, all trading occurs within the Potomac and Susquehanna watersheds, which both lie within the Chesapeake Bay Watershed.