Recycled Water & City Ditch Lakes Recycled Water & City - - PowerPoint PPT Presentation

Recycled Water & City Ditch Lakes

Alan Polonsky Dept Environmental Health Alan Polonsky Dept Environmental Health

Recycle Water Advisory Group 4/26/16 Recycle Water Advisory Group 4/26/16 Recycled Water & City Ditch Lakes

Agend enda

• Data Trends
• Salt
• Nutrients
• Indicators
• Management Actions Update

50 100 150 200 250

2003

2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014

2015

Chloride (mg/L)

Denver Lakes (2003 – 2015)

BERK RMNT SLNS LOLI BARN PFLD VBLT OVRL AQGL HARV GARF HSTN FERL DUK GRAS SMTH Wash Park Lakes WQ standard (230 mg/L)

DataTrends

Sa Salt t – all ll la lakes 2015

Influential Factors Water source

• ground, recycled,

urban/storm runoff Climate

• annual variability

data from 2012 - 2015

• ther lakes used for

park irrigation

DataTrends

Salt lt

50 100 150 200

2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015

Chloride (mg/L)

Grasmere Smith GRS-inflow recycled water no flow to lake SMT-inflow

2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015

Chloride (mg/L)

Grasmere Smith GRS-inflow SMT-inflow

100 200 300 400 500 600

Daphnia magna (water flea) USEPA chronic standard (mussels / clams) Canada WQ Guideline (mussels / clams)

DataTrends

Salt lt

20 40 60 80 100 120 140

2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015

Ferril Smith SMT-INF

Chloride (mg/L)

recycled water

DataTrends

Sa Salt t – City P Park ark

400 600 800 1000 1200 1400 50 100 150 200 250 Sp conductivity (uS/cm) chloride (mg/L) Grasmere Lake (2003 – 2015) 2003 2014 2015

Salt lt

DataTrends

r2 = 0.86

200 400 600 800 1000 1200 1400 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015

Specific Conductivity

conductivity (uS/cm) Grasmere Smith City Ditch

Salt lt

DataTrends

Year total inorganic nitrogen (mg/L as N)

Nutrients ts - Grasmer ere

DataTrends

3 6 9 12 15 18 02 04 06 08 10 12 14 Inflow Mid-lake renovation Inlake – dramatic decrease in 2010 and again in 2012/13 A A A Inflow – dramatic decrease in 2014 B B Influential Factors

• wastewater treatment improvements
• phytoplankton vs rooted veg & algae
• SolarBee location/functionallity
• water exchange
• climate (rain & snow melt)

total phosphorus (mg/L)

0.0 0.1 0.2 0.3 0.4 0.5 02 04 06 08 10 12 14 renovation Inflow Mid-lake

WQ Standard (technically not

applicable to Grasmere or other lakes < 25 acres in size)

5 6 7 8 9 10 40 80 120 160 200 01 03 05 07 09 11 13 15 Grasmere Lake (2001 - 2015)

Chloro-a pH

• 2014)

5 6 7 8 9 10 40 80 120 160 200 01 03 05 07 09 11 13 15

Clorophyll-a (ug/L) Year

Smith Lake (2001

pH (su) Clorophyll-a (ug/L) pH (su)

DataTrends

Indicator tors

Year

pH standard

renovation

5 6 7 8 9 10 40 80 120 160 200 240 01 03 05 07 09 11 13 15 pH (su) chlorophyll-a (ug/L)

Axis Title

Ferril Lake (2001 - 2015)

Chlor-a pH

DataTrends

Indicator tors

Chloro-a pH

Year

pH standard

Pla lanne nned M Mana nagem ement Action

• ns

GB

Washing ngto ton n Park

GridBee (aeration) SolarBee (mixing unit)

GB

Pla lanne nned M Mana nagem ement Action

• ns

aeration (traditional) SolarBee (mixing unit)

City P Park ark

Pla lanne nned M Mana nagem ement Action

• ns

Grasmere

• Aeration should be an improvement overall
• Interaction of increased O2 on chloride fate &

transport?

• Likely little impact on mixing (already had this)

Smith

• How will water mixing impact conditions
• Decrease phyto – increase plants and filamentous
• Keep chlorides in suspension?

Wat Water Qual ality Ou Outcom comes

Ferril

• Aeration combined with mixing should help

improve overall condition

• Decrease phyto

lower pH

Duck

• Aeration should provide enough mixing to

decrease phyto, enhance aquatic life

• Improved aquatic community (good for cormorants)

Al Polonsky 720-865-5480 alan.polonsky@denvergov.org