# Environmental Impact Assessment Requirements
## Mixed-Use Development Projects

### Phase I Environmental Site Assessment
**Required for all projects exceeding:**
- 2 acres of development
- 50 residential units
- 25,000 sq ft of commercial space

**Assessment Components:**
- Historical land use review dating back 50 years
- Review of environmental databases (CERCLIS, RCRA, UST)
- Site reconnaissance and photographic documentation
- Interviews with knowledgeable parties
- Assessment of recognized environmental conditions (RECs)

### Phase II Environmental Assessment Triggers
Required when Phase I identifies:
- Former gas stations or automotive facilities within 500 feet
- Dry cleaning operations (historical or current)
- Industrial facilities with chemical storage
- Underground storage tanks (active or abandoned)
- Soil or groundwater contamination potential

### Wetland Delineation Requirements
**Mandatory assessment if site contains:**
- Seasonal water accumulation areas
- Hydric soils indicators
- Wetland vegetation communities
- Areas within 100 feet of water bodies

**Process Requirements:**
- Professional wetland scientist evaluation
- Army Corps of Engineers jurisdictional determination
- 404 permit application if impacts exceed 0.1 acres
- Mitigation banking or on-site compensation plans

### Stormwater Management Compliance
**Post-Construction Requirements:**
- Retention of first 1.2 inches of rainfall on-site
- Peak discharge rates not to exceed pre-development conditions
- Water quality treatment for 90% of annual runoff
- Long-term maintenance agreements with approved entities

**Green Infrastructure Requirements:**
- Minimum 30% of stormwater managed through green infrastructure
- Permeable pavement for minimum 25% of parking areas
- Bioretention areas sized for 10-year storm events
- Tree canopy coverage of 40% within 10 years

### Air Quality Impact Analysis
**Required for projects with:**
- More than 500 vehicle trips per day
- Parking for 200+ vehicles
- Commercial uses generating odors or emissions

**Assessment Components:**
- Mobile source emission calculations
- Construction dust control plans
- Indoor air quality considerations for residential units
- Compliance with National Ambient Air Quality Standards

### Noise Impact Assessment
**Trigger Levels:**
- Projects within 1,500 feet of highways or arterial roads
- Mixed-use with late-night commercial operations
- Loading docks or mechanical equipment on-site

**Standards:**
- Residential areas: 55 dB daytime, 45 dB nighttime
- Commercial areas: 65 dB daytime, 55 dB nighttime
- Mitigation required if increases exceed 3 dB over ambient

### Historic and Cultural Resource Review
**Section 106 Review Required:**
- Properties 50+ years old within 0.5 miles
- Areas of known archaeological significance
- Traditional cultural properties consultation with tribal authorities

**Documentation Requirements:**
- Historic structures report
- Archaeological survey (if ground disturbance >1 acre)
- Tribal consultation documentation
- State Historic Preservation Office coordination

### Soil and Groundwater Assessment
**Contamination Screening:**
- Lead paint analysis for structures built before 1978
- Asbestos survey for buildings constructed 1940-1980
- Petroleum hydrocarbon testing near former fuel facilities
- Heavy metals analysis in urban brownfield areas

**Remediation Thresholds:**
- Residential soil standards apply to all residential components
- Groundwater monitoring required if contamination detected
- Vapor intrusion assessment for volatile compounds
- Institutional controls may be required for contained contamination

### Wildlife and Habitat Protection
**Protected Species Assessment:**
- Endangered species habitat surveys during breeding seasons
- Migratory bird nesting surveys (March-August)
- Tree surveys for protected or heritage specimens
- Pollinator habitat preservation requirements

### Construction Environmental Controls
**Erosion and Sediment Control:**
- SWPPP (Stormwater Pollution Prevention Plan) required
- Daily inspection and maintenance logs
- Stabilization within 7 days of final grade
- Temporary seeding for areas disturbed >30 days

**Dust Control Measures:**
- Water application during dry conditions
- Stabilized construction entrances
- Vehicle tracking prevention
- Air quality monitoring during demolition

### Timeline and Compliance
**Assessment Timeline:**
- Phase I ESA: 30-45 days
- Phase II ESA (if required): 60-90 days
- Wetland delineation: 45-60 days
- Species surveys: Season-dependent (3-6 months)

**Regulatory Approvals:**
- EPA coordination: 90-120 days
- Army Corps 404 permit: 6-12 months
- State environmental permits: 60-90 days
- Local environmental review: 30-60 days