Stormwater Pollution and Prevention

Construction & Post-Construction

 

The City of Hermantown, along with the Minnesota Pollution Control Agency and the South St. Louis Soil and Water Conservation District have strict laws regarding stormwater water management for construction sites and completed projects. The most common violations involve erosion control and waste management. There are workshops offered annually to help contractors and developers understand and comply with these regulations.

 

Here are some things to remember (Hermantown Code 1060.08.24):

(Common violations are in bold)

 

Before land alteration:

1.  The construction site access road needs to prevent localized erosion and ensure that sediment is not tracked onto public streets or washed into storm drains

2.  All sediment control devices must be installed and stabilized before clearing begins. These include:

a.  Perimeter controls with vegetative buffer strip

b.  Settling basins, sediment traps, or tanks

c.  Hay bales or other barrier protecting stormwater   drains—fiber and rock logs are preferred

3. Upland runoff must be diverted around land alteration area.

4. All adjacent property must be protected by proper sediment control devices.

5. All natural streams, ditches, and wetlands adjacent to project area must be protected by proper sediment control devices.

 

During land alteration:

1. Cut and fill slopes shall be no greater than 2:1.

2. Soil stockpiles must be covered with secures tarps or plastic sheeting at the end of each day.

3.  Prevent debris, dust, or sediment blowing off the site. Weigh down light debris or store in waste bins, bags, or other containers. Dust and sediment can be temporarily reduced by lightly spraying the site with water, or physical devices such as solid board fences, snow fences, and bales of hay may be necessary.

 

Project completion:

1.  Soil stabilization must be completed within 5 days of grading.

2.  Any seeding or planting as an erosion control method must be

       established within 14 days.

NPDES holders are required to complete a stormwater inspection every 7 days and eithin 24 hours after a 1/2" rain event. All stormwater management methods should be evaluated during inspection and repaired if necessary. Any failure of stormwater management techniques results in an illegal discharge. A Stormwater Pollution Prevention Plan (SWPPP) is required for each site. Both inspection logs and the SWPPP must be shown to erosion control inspectors upon request.

 

Remember: attempting to properly manage stormwater is not enough. You are responsible for complying with all sections of City and state erosion control requirements. Failure to comply will result in violations and may lead to enforcement action. All stormwater violations are preventable. The City has a full-time environmental specialist to help answer any questions regarding stormwater: 729-3618.