# Presentation: 014411

## Monitoring and Analytical Issues For BMP Performance Evaluation

**Monitoring and Analytical Issues For BMP Performance Evaluation**

**Hong Lin, Ph.D.**
**Gary Lippner, P.E.**
**CDS Technologies**
**May 9, 2006**
**NWQMC San Jose, CA**

**Notes:**
CDS is an Australian Company  (Public Company – Buy Stock)

The Australians have brought an “Enhanced Vortexing” solid separator to the US in 1996.  This Enhanced Vortexing unit is unique in that it has a balanced set of hydraulics within the separation chamber to produce a non-blocking screen as well.

As of Right Now, Just this Month, We now offer a filter media cartridge in addition to our 

I’m going to first discuss the CDS Enhanced Vortexing system and than discuss the Cartridge filtration system.

## Urban Rainfall-runoff and its pollution

- Esthetic impact, threats to human health, fishes, wildlife
- _Particles and sediments_ :
- Clog fish gills, choke other organisms; Prevent sunlight from reaching aquatic plants
- _Metal elements_ : toxic to aquatic life and potentially contaminant ground water
- _Fertilizers (N, P, K)_ : eutrophication 	_Pathogens_ : threat to human health

- Pavement abrasion

- Urban activities

**Rainfall**

- Urban  pavement surface

**Rainfall-runoff**

**Contaminants**

- Vehicular discharge and abrasion

## BMP Regulations

- National Pollutant Discharge Elimination System (NPDES)
- Phase I – Medium & Large MS4; 11 Categories of Industrial activities
- Phase II – Small MS4
- Total Maximum Daily Load (TMDL)
- Waste load allocations from point sources
- Load allocations from non-point sources and natural background conditions.
- Margin factor

## BMP Monitoring Protocols

- EPA/ASCE Urban Stormwater BMP Performance Monitoring (April 2002)
- The Technology Acceptance Reciprocity Partnership Protocol for Stormwater Best Management Practice Demonstration (TARP) - CA, MA, MD, NJ, PA and VA (July 2003)
- Guidance for Evaluating Emerging Stormwater Treatment Technologies, Technology Assessment Protocol - Ecology (TAPE) Washington Department of Ecology (June 2004)

## BMP Field Monitoring Goals

- Treatment efficiency for targeted pollutants (Reduction Percent and Effluent Quality)
- Hydraulic performance (Treatment flow, Bypass)
- Operation and performance under various flow conditions
- Maintenance requirements

## BMP Monitoring Component

-  Rainfall (depth & intensity)
-  Runoff flow (water quality flow)
-  Sampling (Automatic vs. manual)
-  Sample Management
-  Analytical parameters & methods
-  Data evaluation and validation
-  Quality Analysis/Quality Control (QA/QC)
-  BMP performance evaluation

## “Storm Criteria - Qualified Events”

- Total Rainfall Depth (inch)
- Rainfall intensity (in/hr)
- Antecedent dry period
- Storm coverage (First Flush coverage)
- Number of events
- Influent TSS/SSC Concentration
- Particle Size Distribution

## Total Rainfall Depth & Influent Pollutant Load

**Total Rainfall Depth & Influent Pollutant Load**

-  Solids loading appears to be a power law function of    the total rainfall depth at a CDS MFS monitoring site.

## Rainfall Intensity vs. TSS/SSC

**Rainfall Intensity vs. TSS/SSC**

-  There is no apparent relationship between rainfall intensity and solids concentration & loadings at a CDS MFS monitoring site.

## Storm Coverage

- Composite samples (flow-weighted)
- covering a minimum of 70% of the total storm runoff flow
- Low intensity (flow-limited)
- Pollutant mass delivery proportion to the hydrograph
- High intensity (mass-limited)
- Disproportionate “first flush” of pollutant mass

## Particle Size Distribution (PSD)

- Granulometric characteristics of pollutants
- PSD - d50, d10 and d90
- Determining factor of performance for physical separation

## Particle Size Analysis

**Particle Size Analysis**

-  PSD Analysis using Laser Diffraction Instrument – Monitoring of CDS MFS

## Sampling Structure

-  time-based sampling triggered by flow – CDS MFS Monitoring

## Flow Measurement

- Primary Measuring Device
- Flumes
- Weirs
- Secondary Measuring Device
- Area velocity flow meter
- Velocity sensors w/depth sensors
- Installation & Calibration

## Sample Collection

- Automatic Sampler
- Sampling location
- Sampling structure (time-based vs. flow-based)
- Limited application in the sediment-laden runoff
- Convenient and less labor intensive
- Manual Sampling
- Full-cross sectional manual sampling - representative samples
- Time consuming & Labor intensive
- Can be applicable for some field installations

## Sediment and Floatable Fractions in Urban Storm Water Runoff

- Heterogeneous mixture of particulate materials from a variety of anthropogenic and natural sources
- > 75 m
- Variable s
- Separated at #200 sieve (75-m)

- Automatic Sampling

- CDS Sump Materials

- Trapezoidal
- Flume

## Mass Balance Approach

- True Influent Load = Captured Pollutant Load in BMP + Effluent Load (Auto sampler) + Bypass Load

## Mass Balance Approach Methodology

**Mass Balance Approach Methodology**

## CDS Sump SolidsCharacterization(Mass Balance Approach)

- CDS Sump SolidsCharacterization(Mass Balance Approach)

- Remove solids using vacuum truck or manually
- Place in phase separator or storage tank
- Decant water, air dry solids and measure volume
- Sub-sample entire volume or use successive quartering techniques for large quantities

- Analysis -  Total Solids, Total Volatile Solids, Grain size distribution (PSD), S.G.

## CDS Sump Material PSD vs. Other Studies

**CDS Sump Material PSD vs. Other Studies**

- * NURP - National Urban Runoff Program (1982)

- CDS Sump Material
- at Various Sites

## Analytical Procedure

- Composite and Sub-sampling
- Flow weighted composite samples
- Cone Splitter for sub-sampling
- Total Suspended Solids (TSS) vs. Suspended Sediment Concentration (SSC)
- APHA Method 2540D
- ASTM Method D3977-97
- Maximum Detection Limit
- Partitioning of Phosphorous and Metals – Fractionation immediately after sampling

## Data Evaluation

- Individual Storm Event – Pollutant Reduction
- Concentration (mg/L)
- Mass Loading (g)
- Accumulated Pollutant Load Reduction – Mass Balance Approach
- Removal percentage and Effluent quality
- Statistical goals – cov, C.I.

## Statistical Goals

- Number of Events
- Coefficient of variance
- Confidence Internal

| Treatment level | Standard | COV | Min # of Sample Pairs |  |
| --- | --- | --- | --- | --- |
|  |  |  | C.I. 95 | C.I. 90 |
| Basic  | 80% SSC  | 0.55 | 6 | 5 |
| TP | 50% TP | 0.75 | 28 | 20 |

- Washington Ecology - TAPE protocol

## BMP Performance Evaluation

- Treatment Performance
- Solid (TSS/SSC) removal
- Total metals, Total Phosphorous
- Dissolved pollutants
- Hydraulic performance
- Treatment flow vs. Bypass flow
- Headloss
- Operation & Maintenance
- Frequency
- Procedure

## Summary

- Accurate flow measurement is critical for the BMP monitoring in order to determine system hydraulic performance and pollutant load.
- Particle size analysis is critical for comparing system performance.  d50, d10 and d90 are necessary to define a PSD.
- A mass balance approach by characterizing the pollutant load captured in the BMP can correct the inaccuracy of auto sampling for sediment-laden (>63-m) urban runoff flow.

## Summary - Cont. 

- SSC analytical method provides accurate pollutant loading analyses for the urban runoff flow.
- Compositing and Sub-sampling using cone-splitter is efficient for analyses of particles less than 500-m.
- Load reduction and effluent quality should be the ultimate performance evaluation criteria for BMPs.

## BMP Monitoring & Evaluation

- Site Selection

- Data Acquisition

- Water Quality Analyses

- Treatment Performance

- Rainfall

- Runoff
- Flow

- Sample

- Percent Removal

- Effluent Quality

- Mass Loading Reduction

- BMP Evaluation

- Hydraulic Performance

- Operation & Maintenance