# Presentation: 316952

## Construction Site Best Management Practices

- May 2005
- Kristine Karlson
- EPA Region 10

## Introduction

- Presentation focus: “site review” portion of construction site inspection
- Review potential pollutant sources in relation to possible points of discharge
- Best management practices (BMPs) must be properly _selected_, _installed_ and _maintained_ to contain or reduce each of these pollutants

## Construction Site BMP Overview

| Pollutant | Source | BMPs |
| --- | --- | --- |
| Sediment | Any disturbed areas, site entrances, run-on waters, excavation, discharge points | 1.     Prevent erosion by stabilizing
2.     Capture sediment on site |
| pH (high) | Concrete/grout batching and washout areas | 3.     Prevent discharge of concrete/mortar |
| Oil, grease & other toxic pollutants | Storage, maintenance and fueling areas | 4.     Prevent contact with storm water |
| Litter & debris | Throughout site, storage areas | 5.     Contain in bins / dumpsters & remove from site |

## 1 - Sediment: Erosion Control BMPs

- Goal: prevent soil particles from being dislodged in the first place
- Revised Universal Soil Loss Equation (RUSLE):
- A = R K (LS) C P       (soil loss in ton/acre/yr)where:	R = rainfall-runoff erosivity factor (on map)		K = soil erodibility factor
- 			LS = slope length and steepness factor  	   		C = cover-management factor 		P = supporting-practices factor

## 1 - Sediment: Erosion Control BMPs

- Non-structural BMPs:
- Know your seasons – schedule work for seasons with less precipitation/wind
- Avoid clearing/grading on large areas at one time – use natural vegetation as erosion control
- Set clearing limits – avoid disturbing more than you have to

## Structural BMPs should be found at:
Site entrance
Anywhere clearing or grading occurs
Fill piles and borrow areas (sometimes offsite)
Run-on & runoff water locations

- Site entrance
- Anywhere clearing or grading occurs
- Fill piles and borrow areas (sometimes offsite)
- Run-on & runoff water locations

- 1 - Sediment: Erosion Control BMPs

## Erosion Control at the Site Entrance

- Heavy equipment traffic
- Offsite soil tracking & dust generation
- Potential discharge to storm drains/ditches along roadway
- BMPs: Stabilize entrance and/or capture sediment

**Notes:**
Pre-planned inspections are designed to target known areas where water quality problems are likely
--impaired water bodies (in this case, we’d look at those waters the state has told us are overloaded with sediment)
--larger construction sites (especially those near water)

Complaints from public:
--come from neighbors concerned about water quality or erosion problems they’ve seen
--local and state agencies have called EPA for assistance with problem sites
--EPA can respond to  with inspectors from Seattle or from our offices in Idaho

## Site entrance: No off-site tracking controls

- Site entrance: No off-site tracking controls

## Site entrance stabilized with Rock – Partially Effective

- Site entrance stabilized with Rock – Partially Effective

## Site entrance: Stabilization with Rock - Effective

- Site entrance: Stabilization with Rock - Effective

## Site Entrance Sediment Controls: Truck Wash/Drain

- Site Entrance Sediment Controls: Truck Wash/Drain

## Entrance Sediment Controls: Wheel Wash

- Entrance Sediment Controls: Wheel Wash

## Other Site Entrance Sediment Tracking Controls: 

- Street Sweeping
- Shake Bars
- Drive-thru Basins

## Erosion Controls At Other Areas of Soil Disturbance

- Cut and fill slopes
- Areas undergoing grading
- Fill piles & borrow areas
- Federal permit requirement: Stabilize soil with erosion controls within 14 days

**Notes:**
Pre-planned inspections are designed to target known areas where water quality problems are likely
--impaired water bodies (in this case, we’d look at those waters the state has told us are overloaded with sediment)
--larger construction sites (especially those near water)

Complaints from public:
--come from neighbors concerned about water quality or erosion problems they’ve seen
--local and state agencies have called EPA for assistance with problem sites
--EPA can respond to  with inspectors from Seattle or from our offices in Idaho

## Borrow area with no erosion controls

**Notes:**
Stabilization of disturbed soils is required within 14 days, unless construction will occur at the disturbed area within 21 days.

## Stabilization (Erosion Controls)

- Surface Roughening & Terracing
- Plastic
- Mulching
- Erosion Control Blankets
- Vegetation
- Existing
- Applied - Hydroseeding/Bonded Fiber Matrix/Sod

## Erosion Controls: Surface Roughening

## Erosion Controls: Surface Roughening – Partly Effective

- Erosion Controls: Surface Roughening – Partly Effective

- Best in Combination w/other BMPs

## Erosion Controls: Plastic – low tech, but not cheap – or easy

- Erosion Controls: Plastic – low tech, but not cheap – or easy

## Erosion Controls: Mulch

**Must be applied very thickly to be effective – if you can see the soil, it’s not working**

## Erosion Controls: Erosion Control Blankets (Here: Straw Matting)

**May be much more effective than mulch on steeper slopes & in windy areas**

## Erosion Controls: Hydroseeding – Installation & Maintenance

- Consider season
- Apply when soil is dry
- Apply in growing season
- May require irrigation
- May need protection
- Keep away from concentrated flows

## Erosion Controls: Hydroseeding(Bonded Fiber Matrix) – Poor Installation

- Erosion Controls: Hydroseeding(Bonded Fiber Matrix) – Poor Installation

## Erosion Controls: Hydroseeding Protected with Jute

- Erosion Controls: Hydroseeding Protected with Jute

## The Mother of All Erosion Controls

## Control Run-On Water: Slope Drains

**A simple, cost effective means of temporarily conveying water over exposed areas until permanent drainage systems and/or stabilization are completed.**

## Run-on water:- erodes roadways - pollutes otherwise clean water

- Run-on water:- erodes roadways - pollutes otherwise clean water

## Controlling Run-On Water: Pipe Slope Drains

## Run-on water: erodes slopes,  disrupts stabilization efforts

- Run-on water: erodes slopes,  disrupts stabilization efforts

## Runoff water erodes unprotected ditches

## Check Dams & Liners Protect Ditches from Erosion

## Controlling run-on water: a rock-lined diversion channel

## Run-On Water: Check Dams and liner

## 2 - Sediment Control BMPs

- Goal: capture any dislodged soil before it leaves the site.  THIS ALSO MEANS _BEFORE_ IT ENTERS A WATERWAY!!!
- Keep in mind that sediment controls will not “treat” turbid discharges – only capture heaviest soil particles

## 2 - Sediment Control BMPs

- Where usually located?
- Perimeter of site
- Toe of slope/base of fill piles
- Along discharge pathways
- At discharge points
- Where excavation dewatering occurs

## Sediment Controls: Silt Fences

## A well-installed silt fences

- A well-installed silt fences

## Silt Fences: You always hurt the ones you love...

- Silt Fences: You always hurt the ones you love...

**Notes:**
Loss of topsoil.

More maintenance of sediment controls needed.

Only the largest particles are settled out - most pollutants were carried away in the water column downstream.

## Silt fences are not filters

## Silt Fence As Improperly Selected BMP

## Badly placed silt fence may do more harm than good...

## Improperly Installed Silt Fence

**Notes:**
Silt fences not entrenched – sediment runs right beneath them.
This picture is of an unstabilized fill pile

## Silt Fence Doing Its Job, But Not Being Maintained

- Silt Fence Doing Its Job, But Not Being Maintained

**Notes:**
Permit requires that sediment be removed when capacity is reduced by 50%.

## Sediment Controls: Sediment Basins

## Sediment Basin Issues...

**Location **
**Sloped vs. flat?**
**Adequate space for proper sizing?**
**Should be in upland area – not built into a stream or other water body**
**Construction**
**Should be made of compactable soils**
**Lined vs. raw**

## Unlined Sediment Basin

## Sediment Basin Blowout:

**Notes:**
Sediment Accumulations – may fill or change course of waterway, smother wildlife habitat
Erosion of Stream Banks – may cause property damage, loss of habitat

## More Sediment Controls: Excavation Dewatering BMPs

- Avoid wet season --> avoid groundwater
- Use sediment controls
- Dirt bags
- Sediment basins
- Use of coagulants/flocculants
- Chemical (Polyacrylamides)
- Chitosan – http://naturalsitesolutions.com
- Electro-coagulation

## Excavation Dewatering: No sediment controls

- Excavation Dewatering: No sediment controls

## Excavation Dewatering BMP: Dirt Bag

## Excavation Dewatering: Dirt Bag Not Maintained - Ineffective

- Excavation Dewatering: Dirt Bag Not Maintained - Ineffective

## The end of the line: storm drain inlet protection

- The end of the line: storm drain inlet protection

## Without inlet protection, sediment continues downstream...

## 3 - pH – Another Potential Pollutant

- Usual suspects:
- Concrete batching operations
- Concrete or mortar disposal areas
- Such “industrial activities” not allowed to discharge under the CGP
- BMP: prevent discharge

## Concrete Batching Operations...

## ... and concrete washout areas: establish location & ensure no discharge

- ... and concrete washout areas: establish location & ensure no discharge

## Well-planned concrete washout area...

## Poorly-planned/maintained concrete washout area – within bermed storage yard...

## ...Concrete discharges to wetland.  This silt fence is not appropriate for total containment.

- ...Concrete discharges to wetland.  This silt fence is not appropriate for total containment.

## Practice “Good Housekeeping” by ensuring storm water does not come into contact w/these materials
Cover from the elements
Contain spills
Dispose of hazardous materials in a proper manner

- Cover from the elements
- Contain spills
- Dispose of hazardous materials in a proper manner

- 4 - Oil, grease & other construction materials as possible pollutants

## Covered, contained storage areas are ideal...

## The less contained, the less ideal...

## The less contained, the less ideal...

## 5 - Litter: Another Possible Pollutant

## Dumpsters are the best BMP

## Recap

| Pollutant | Source | BMPs |
| --- | --- | --- |
| Sediment | Any disturbed areas, site entrances, run-on waters, excavation, discharge points | 1.     Prevent erosion by stabilizing
2.     Capture sediment on site |
| pH (high) | Concrete/grout batching and washout areas | 3.     Prevent discharge of concrete/mortar |
| Oil, grease & other toxic pollutants | Storage, maintenance and fueling areas | 4.     Prevent contact with storm water |
| Litter & debris | Throughout site, storage areas | 5.     Contain in bins / dumpsters & remove from site |

## Q & A