ISGP: Assess Your Site
There are several things that need to be considered prior to and during your application for a permit. You will need to conduct quite a lot of research prior to completing the Notice of Intent (NOI) and the Stormwater Pollution Prevention Plan (SWPPP) for your site.
It may be helpful to look at Ecology’s SWPPP Template and this Example NOI as you assess your site to get an idea of what information you may need. Please note that this information includes, but is not limited to, the items below.
Site History
Gathering information regarding the history of your site can be a crucial step in gaining permit coverage without delay. You will want to gather any information about your site that is available to you. This can be existing site maps or drawings, information regarding any previous industrial activity that occurred on the property, information about any permit requirements or challenges previous operators on your site faced, and any information documenting existing contamination on the property. These items will all allow you to fill out the required applications and forms much faster.
Owner/Operator
You will need to gather the contact information of the site owner and operators. If the property is being leased, it is important that the landlord is aware of the permit requirements you are required to comply with. You will also want to find out what maintenance services are included in your lease as well as the timing and frequency of those services. Items such as site sweeping and catch basin cleaning are required under the permit, so it is helpful to know if these activities are included in your lease.
If the corporate office for your operation is out of state, it is important that someone on site is given signatory authority to submit information to ecology and to receive Ecology communications. This information is covered more in-depth in the Apply for Coverage section
Infrastructure
You will also need to evaluate your site’s infrastructure and start thinking of how stormwater will interact with it. Walk your site and look closely at the infrastructure. Identify all of the impervious surfaces (hard surfaces that won’t infiltrate such as roofs, roads, parking lots, etc.) on your site and take note of the material they are made from and their condition. You will also want to find all the subgrade piping and other drainage infrastructure noting their materials and conditions. As part of the permitting process, you will be required to identify where these structures flow to, so you may want to reference site maps as you walk your site. You may also want to have discussions with previous site owners or your local jurisdictions to ensure your understanding of the subgrade infrastructure is correct.
Weather
It is important to start thinking about how the climate your facility is in will affect your site. Different areas of Washington can experience significantly different weather patterns. Western Washington, for example, is known for its long periods of light rain during the winter, while areas of Eastern Washington are often drier but may experience heavier downpours or significant snowfall. The rainfall intensity (how hard it is raining), duration (how long it is raining), and seasonality (what time of year it rains) can play an important role in how stormwater is managed on your site.
Receiving Waters & Sensitive Species
It is important to know where the stormwater goes after it leaves your site. Some sites may simply run off into a field and infiltrate into the ground, while others may enter a complex system of ditches and drainages before entering a sensitive water body. It may be useful to use local GIS mapping to see where any of these conveyances lead. The receiving waters your stormwater enters can play a critical role in sampling, monitoring, and treatment requirements, so it is important that the receiving waters are correctly identified.