On Construction or Land Disturbance Sites, soil is highly vulnerable to erosion by wind and water. Eroded soil endangers water resources by reducing water quality and causing the siltation of aquatic habitat for fish and other desirable species. Deposits of eroded soil also necessitate maintenance of sewers and ditches and the dredging of lakes. In addition, clearing and grading during construction cause the loss of native vegetation necessary for terrestrial and aquatic habitat. Construction activities also utilize materials and generate wastes, which if not properly controlled can pollute receiving waters.
St. Louis County Land Disturbance
Any disturbance inside the public right-of-way, that is designated as a part of the County Road System (CRS):
will require a Special Use Permit;
applies in unincorporated and municipalities with County mainted streets.
Any land disturbance activity involving 1 acre or more of land, or a site involving less than 1 acre that is part of a proposed development that will ultimately disturb 1 acre or more:
will require a Major Land Disturbance Permit and SWPPP;
applies in unincorporated County and in contracting municipalities.
Any land disturbance activity involving less than 1 acre of land:
will require an Ordinary Land Disturbance Permit and BMP's;
applies in unincorporated County and in contracting municipalities.
Any land disturbance activity involving less than 30 cubic yards of soil / earth moved and less than 2,000 square feet of disturbed area;
will not require a land disturbance permit;
applies in unincorporated County and in contracting municipalities;
erosion control is required when necessary, until vegetation is established.
STORM WATER POLLUTION PREVENTION PLAN (SWPPP)
A Storm Water Pollution Prevention Plan (SWPPP), signed and sealed by a Professional Engineer licensed in the State of Missouri, prepared for the specific site by or under the direction of said Professional Engineer, must be submitted for any Major Land Disturbance Activity. The plans shall contain a statement that any land clearing, construction, or development involving the movement of earth shall be in accordance with the SWPPP, and the person issued a Land Disturbance Permit assumes and acknowledges responsibility for compliance with the St. Louis County Land Disturbance Code and the approved SWPPP at the site of the permitted activity. The SWPPP assumes St. Louis County land disturbance criteria are applied to the project. If different criteria are proposed, permission from the County must be obtained. The SWPPP shall clearly state land disturbance criteria to be used. If the SWPPP project crosses municipal boundaries, land disturbance criteria arrangements between boundary authorities need to be stated in the SWPPP. When a County linear road project is located in a municipality(s), in whole or in part, the County land disturbance code shall be followed. A land disturbance permit from the municipality(s) shall not be required. The municipality(s) will be notified of the proposed construction and will be given opportunity to review the plans before the start of construction. For additional information see Section 806 of St. Louis County's Standard Specification for Highway Construction.
The contractor / permit holder shall insure that what is shown on the SWPPP matches what is in the field.
The contractor / permit holder shall insure that utility companies, subcontractors, employees, etc., are made aware of and follow all SWPPP requirements.
A SWPPP shall include the following information:
1) Name, address and telephone number of the site owner and the name, address and telephone number of the individual(s) who will be in overall responsible charge of construction and development activities at the site. If more than one individual is responsible for the site, identify the areas of the site over which each individual has control.
2) Site address or location description and parcel identification number(s). Description of nature of activity.
3) A site map showing the outlines of the total project area, the areas to be disturbed, existing land uses, locations and names of surface water bodies, discharge points, locations of flood plains, and locations of temporary and permanent BMP's, a general location map, and off-site materials and such other information as may be required by the County department(s) having enforcement authority and responsibilities described in the code. Determine if storm water runoff from the project flows into "Valuable Resource Water", as defined by the Missouri Department of Natural Resources, and clearly label on SWPPP.
4) Existing contours of the site and adjoining strips of off-site property and proposed contours after completion of the proposed land disturbance and development, based on United States Geological Survey datum, with established elevations at buildings, walks, drives, street and roads; and information on necessary clearing and grubbing, removal of existing structures, excavating, filling, materials brought to the site, spreading and compacting. Existing and proposed contours shall be shown at two (2) foot elevation intervals. Cross sections may be utilized in lieu of contours as approved by the Department of Highways & Traffic.
5) A natural resources map identifying soils, forest cover, and resources protected under other provisions of St. Louis County Ordinances.
6) An estimate of the Runoff Coefficient of the site prior to disturbance and the Runoff Coefficient after the construction addressed in the permit application is completed.
7) Estimated quantity of land to be disturbed.
8) Details of the site drainage pattern both before and after Major Land Disturbance Activities.
9) Stabilized access to the construction site.
10) Description of the BMP's to be utilized to control erosion and sedimentation during the period of land disturbance. A table is to be provided that lists each BMP to be utilized and the quantity of each (the quantity for silt fence, etc. is to be listed in linear footage). Label each BMP in the table as temporary or permanent.
11) Identify potential sources of pollution, waste and construction materials expected to be stored on site (with updates) and a description of the BMP's to be utilized to prevent the potential pollutants (construction wastes, toxic or hazardous substances, petroleum products, paints, solids, pesticides, herbicides, site litter, sanitary wastes, etc.) from entering the natural drainage ways and / or waters of the U.S. during the period of construction and land disturbance.
12) Description of the BMP's that will be installed during land disturbance to control pollutants in storm water discharges that will occur after land disturbance activity has been completed.
13) Location of stabilized temporary off-street parking, wash-down, and maintenance area for related vehicles.
14) Sources of off-site borrow material or spoil sites, and all information relative to haul routes, trucks and equipment.
15) The anticipated sequence of construction and Land Disturbance Activities, including installation of BMP's, removal of temporary BMP's, stripping and clearing; rough grading; construction utilities, infrastructure, and buildings; and final grading and landscaping. Sequencing shall identify the expected date(s) on which clearing will begin, the estimated duration of exposure of cleared areas, areas of clearing, installation of temporary erosion and sediment control measures, and establishment of permanent vegetation. Record dates of major grading activities, construction temporarily or permanently ceased and stabilization measures initiated.
16) All erosion and sediment control measures necessary to meet the objectives of this ordinance Code throughout all phases of construction and after completion of site development. Depending upon the complexity of the project, the drafting of intermediate plans may be required at the close of each season.
17) Seeding mixtures and rates, types of sod, method of seedbed preparation, expected seeding dates, type and rate of lime and fertilizer application, and kind and quantity of mulching for both temporary and permanent vegetative control measures.
18) Provisions for maintenance of control facilities, including easements.
19) Plans for responding to any loss of contained sediment or other pollutant to include the immediate actions the permit-holder will take in case of a containment failure. This plan must include documentation of actions and mandatory reporting to the St. Louis County Department of Public Works.
20) Schedules and procedures for routine inspections of any structures provided to prevent pollution of storm water or to remove pollutants from storm water and of the site in general to ensure all BMP's are continually implemented and are effective.
21) Locate state and county land disturbance permits with the SWPPP.
22) Description of measures that will be installed during the construction process to control pollutants in storm water discharges that will occur after construction operations have been completed. During construction, strategies shall be implemented to protect post construction BMP's.
23) Location / description of industrial activities like temporary, on site, concrete or asphalt batch plants.
24) Include applicable endangered species and historic properties documentation in the SWPPP.
25) Include list of EPA allowable sources of non-storm water discharges, and identify "Allowable Non-Storm Water Discharges". The EPA list as of January 2011 is included below. The U.S. EPA "National Pollutant Discharge Elimination System (NPDES)" website is located at:
http://cfpub.epa.gov/npdes or www.epa.gov/ne/npdes/permits/permit_final_ms4.pdf
The following non-storm water discharges are authorized by the EPA provided it has been determined by the permittee that they are not significant contributors of pollutants to the MS4. Implementation of pollution prevention measures for non-storm water discharges is required for significant contributors.
a) Water line flushing.
b) Landscape irrigation.
c) Diverted stream flows.
d) Rising ground waters.
e) Uncontaminated ground water infiltration (as defined at 40 CFR 35.2005(20)).
f) Uncontaminated pumped ground water.
g) Discharge from potable water sources.
h) Foundation drains.
i) Air conditioning condensation.
j) Irrigation water, springs.
k) Water from crawl space pumps.
l) Footing drains.
m) Lawn watering.
n) Individual resident car washing.
o) Flows from riparian habitats and wetlands.
p) De-chlorinated swimming pool discharges.
q) Street wash water.
r) Residential building wash waters, without detergents.
Discharges or flows from fire fighting activities occur during emergency situations. The permittee is not expected to evaluate fire fighting discharges with regard to pollutant contributions. Therefore, these discharges are authorized as allowable non-storm water discharges, unless identified, by EPA, as significant sources of pollutants to Waters of the U.S.
26) Include a description of any anticipated dewatering methods.
27) Signed certification statement.
Disclaimer: This information is not intended to be a policy for designing plans and specifications, but a source of information about land disturbance best management practices.