**[Topic List:]{.underline}**

1.  Electrocoagulation and Passive Filtration **-** Jim Mothersbaugh of
    Water Tectonics

**[Topic Summary:]{.underline}**

**Electrocoagulation and Passive Filtration -** Jim Mothersbaugh of
Water Tectonics

Jim has an extensive professional background in wastewater and storm
water treatment technology including exploring tertiary treatment in the
Tahoe Basin in 1970. He founded the Seattle firm Water Tectonics, Inc.
in 1999 which specializes in developing new storm water treatment
technology to comply with strict federal and state discharge
requirements in the state of Washington. The goals of Water Tectonic,
Inc. are to develop and produce user friendly, low maintenance treatment
technology packages to meet specific needs. Electrocoagulation is a
storm water treatment technology that uses electrification of specific
media plates within a treatment cell to cause coagulation of targeted
dissolved metals, nutrients, and sub-micron particles by creating
positively charged molecules to drawn negatively charged pollutant
molecules into a larger coagulated solid mass.

Field studies of this technology reduced turbidity (from sediment) in
storm water runoff from large construction sites (8.3 and 23 acres) to
below 10 and frequently 5 NTUs. Electrocoagulation is used as part of a
treatment train that removes course sediment prior to electrocoagulation
and provides settling or filtering of coagulated particles after
electrocoagulation. An electrocoagulation cell can operate 24/7 without
an operator because has totally computerized system controls to respond
to varying flow rates (25 to 500 gpm) and total conductivity. Unlike
chemical coagulation, electrocoagulation requires less electricity to
treat higher concentrations of target pollutants and electrocoagulation
works well through a range of pH (pH insensitive). The challenge of
treating low conductivity storm water may be improved by recycling a
portion of the waste stream with higher conductivity through the
electrocoagulation cell with the influent storm water. No ecological
toxicity is created in storm water treated with electrocoagulation based
on bioassays with rainbow trout. Examination of the coagulant produced
by electrocoagulation, show that it is a tightly formed mass that has
good stability. The following total treatment train cost estimates were
provided for a 300 gpm system: electrocoagulation cell system =
\$250,000, solids separation system = \$100,000 (for a total capital
improvement cost of \$350,000), and maintenance costs of \$1.80 per 1000
gallons. The maintenance cost is based on cell plate replacement costs
with the assumption of a 500,000 gallon total cell life. While it is an
electrical process, the actual demand is low, and typically runs 2
kilowatts per 1000 gallons (or 16¢/1000 gallons). The land requirements
for such a system would include space for an 8' by 20' trailer to house
the electrocoagulation cells and space for pre- and post- treatment
settling basins (and/or sand filter). Numerous collection and treatment
train configurations of possible for utilizing electrocoagulation and
Jim encourages interested parties to contact Water Tectonics, Inc for
treatment option recommendations.

Jim also presented two other Water Tectonic's/Royal Environmental
Systems products, the pHat Box for providing automated pH treatment for
regulations compliance, and the EcoStorm for treating collected storm
water runoff for sediment and phosphorus. The EcoStorm treats storm
water by sedimentation (hydrocyclonic separator), adsorption to the
modified porous concrete surface, chemical precipitation driven by the
pH adjustment provided by the alkaline composition of the filter, and
filtration. The upward flow of storm water through the EcoStorm allows
for gravity enhanced filter back flushing. EcoStorm is designed to tie
into drainage inlets (DIs) for storm water collection. Jim informed us
that the analysis standard for total suspended solids (TSS) is changing
to reflect a better chemistry based understanding. The presentation
ended with treatment demonstrations of both electrocoagulation of a
dissolved pollutant and sediment laden water through the EcoStorm.

For more information on the new technologies presented, go to:
<http://www.watertectonics.com/index.html>, or contact Jim Mothersbaugh
at: [jim@watertectonic.com](mailto:jim@watertectonics.com).

In Attendance:

Jay Aldean, HDR\*

Nancy Alvarez, USGS- WRD\*

Scott Brown, NTCD

Scott Carrol, CTC

Scott Cecchi, CTC

Jeff Curtis, ECO:LOGIC

Charlie Danohue, NDSL

Mike Elam, TRPA

Brendan Ferry, EDOT

Steve Goldman, CTC

Kim Gorman, Lahontan\*

Elizabeth Harrison, NDSL

Mark Hoefer, JWA

Shannon Horgan, TRPA

Christine Kirick, Wood Rodgers

Erik Larson, TRPA\*

Jason Kuchnicki, NDEP

Charlie Miller, Entrix

Steve Peck, Entrix

Greg Porter, CDM\*

Dave Rios, NTCD\*

Tim Rowe, USGS

Andrew Ryan, Pastor Ryan

Catherine Schoen, USFS\*

Jessica Schwiwg, TRPA

Laurie Scribe, Lahontan

Mark Sedlock, CTC

Penny Stewart, CTC

Chuck Taylor, NRCS

Chris Twomey, c2me

Matt Vitale, NTCD

Rita Whitney, TRPA\*

Russ Wigart, CTC

Next Agenda\*: