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

Recycled Water & City Ditch Lakes Recycled Water & City Ditch Lakes Recycle Water Advisory Group 4/26/16 Recycle Water Advisory Group 4/26/16 Alan Polonsky Alan Polonsky Dept Environmental Health Dept Environmental Health

Agend enda • Data Trends Salt o Nutrients o Indicators o • Management Actions Update

DataTrends Sa Salt t – all ll la lakes 2015 Denver Lakes (2003 – 2015) Influential Factors 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 Water source ground, recycled, 250 WQ standard (230 mg/L) • urban/storm runoff 200 Climate Chloride (mg/L) annual variability • 150 100 50 data from 2012 - 2015 0 BERK RMNT SLNS GRAS SMTH FERL DUK HARV GARF HSTN OVRL AQGL LOLI VBLT BARN PFLD other lakes used for park irrigation Wash Park Lakes

Salt lt Chloride (mg/L) 100 150 200 50 0 no flow to lake 2003 recycled water GRS-inflow Grasmere 2004 2005 2006 2007 SMT-inflow Smith 2008 2009 2010 2011 2012 2013 2014 DataTrends 2015

DataTrends Salt lt 600 Daphnia magna (water flea) Grasmere Smith 500 Chloride (mg/L) GRS-inflow SMT-inflow 400 300 USEPA chronic standard (mussels / clams) 200 Canada WQ Guideline (mussels / clams) 100 0 2003 2004 2005 2006 2007 2008 2009 2011 2013 2014 2015 2010 2012

Sa Salt t – City P Chloride (mg/L) 100 120 140 20 40 60 80 0 Park 2003 ark recycled Smith water 2004 2005 Ferril 2006 2007 SMT-INF 2008 2009 2010 2011 2012 2013 DataTrends 2014 2015

DataTrends Salt lt Grasmere Lake (2003 – 2015) 1400 Sp conductivity ( u S/cm) 1200 2014 1000 2015 800 2003 600 r 2 = 0.86 400 0 50 100 150 200 250 chloride (mg/L)

Salt lt conductivity ( u S/cm) 1000 1200 1400 200 400 600 800 0 1997 Specific Conductivity 1998 1999 2000 2001 2002 2003 2004 2005 City Ditch Smith Grasmere 2006 2007 2008 2009 2010 DataTrends 2011 2012 2013 2014 2015

DataTrends Nutrients ts - Grasmer ere Inflow Mid-lake 18 Inlake – dramatic decrease in 2010 total inorganic nitrogen A 15 and again in 2012/13 12 (mg/L as N) B Inflow – dramatic decrease in 2014 B 9 renovation 6 A 3 A WQ Standard (technically not 0 applicable to Grasmere or other lakes < 25 02 04 06 08 10 12 14 acres in size) Year 0.5 total phosphorus (mg/L) Inflow Influential Factors Mid-lake 0.4 - wastewater treatment improvements - phytoplankton vs rooted veg & algae 0.3 - SolarBee location/functionallity - water exchange renovation 0.2 - climate (rain & snow melt) 0.1 0.0 02 04 06 08 10 12 14

DataTrends Indicator tors Grasmere Lake (2001 - 2015) 200 10 Clorophyll-a (ug/L) pH standard 160 9 pH (su) 120 8 renovation 80 7 Chloro-a 40 6 pH 0 5 01 03 05 07 09 11 13 15 Smith Lake (2001 - 2014) Year 10 Clorophyll-a (ug/L) 200 9 160 8 pH (su) 120 7 80 6 40 0 5 01 03 05 07 09 11 13 15 Year

DataTrends Indicator tors Chloro-a Ferril Lake (2001 - 2015) pH Chlor-a pH 240 10 chlorophyll-a (ug/L) 200 9 pH standard 160 pH (su) 8 120 7 80 6 40 0 5 01 03 05 07 09 11 13 15 Axis Title Year

Pla lanne nned M Mana nagem ement Action ons Washing ngto ton n Park GB GridBee (aeration) GB SolarBee (mixing unit)

Pla lanne nned M Mana nagem ement Action ons City P Park ark aeration (traditional) SolarBee (mixing unit)

Pla lanne nned M Mana nagem ement Water Qual Wat ality Ou Outcom comes Action ons Grasmere • Aeration should be an improvement overall o Interaction of increased O2 on chloride fate & transport? • Likely little impact on mixing (already had this) Smith • How will water mixing impact conditions o Decrease phyto – increase plants and filamentous o Keep chlorides in suspension? Ferril • Aeration combined with mixing should help improve overall condition o Decrease phyto lower pH Duck • Aeration should provide enough mixing to decrease phyto, enhance aquatic life o Improved aquatic community (good for cormorants)

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