Broomfield s Harmful Algal Bloom Experiences. Laura Hubbard Environmental Laboratory Supervisor City and County of Broomfield CLRMA, April 23, 2015

Transcription

1 Broomfield s Harmful Algal Bloom Experiences Laura Hubbard Environmental Laboratory Supervisor City and County of Broomfield CLRMA, April 23, 2015

2 Broomfield Pond Monitoring About 34 square miles More than 40 stormwater retention ponds Routinely monitor 23 ponds Largest is 15 surface acres Smallest is 1/3 surface acre Depth ranges from 0.5 m to 10 m Water quality data Aesthetics (odors, mosquitoes, trash, scum)

3 Where are these ponds?

4 Why We Monitor Stormwater Retention Ponds Help our Parks Division by providing data for operations and maintenance support Circulation system for Alexx and Michael s Pond in 2012 Circulator for Sagar Reservoir in 2014 Weekly reports address: Trash pickup needed Aerators/circulators operation Unusual field data

5 Why We Monitor Stormwater Retention Ponds Maintain aesthetic values of the ponds Better serve our community

6 Laboratory Data for Ponds Water Quality Data General Characteristics: TDS, TSS, alkalinity, hardness, chloride, sulfate Nutrients: ammonia, nitrate, orthophosphate, total phosphorus Microbiology: Total coliform and E. coli, chlorophyll a, COD and algae identification/quantification Metals

7 Peacful, Quiet Winter Josh s Pond 10 th Avenue Pond

8 Cheerful Spring Josh s Pond Big Dry Creek

9 Summer is Here!! Brunner Reservoir 5/19/13 The Trails Pond 2008

10 Dog Days of Summer The Trails Pond 8/26/10 Microcystin concentrations 5 to 500 µg/l (July through October), Oscillatoria alternating with Microcystis

11 The Trails Pond Microcystin greater than 100 µg/l, Oscillatoria alternating with Microcystis 9/2/11

12 The Trails Pond What is this? 5/22/13 Date Algae Field # cells/ml Blue Green Diatom Green Flagellate 5/6/2013 Synedra 867 x 5/6/2013 Scenedesmus 2533 x x 5/6/2013 Cyclotella x 5/6/2013 Cryptomonas 1800 x 5/6/2013 Ankistrodesmus 3467 x 5/6/2013 Closterium 1200 x 5/6/2013 Coelastrum 800 x 5/6/2013 Microactinum 3800 x 6/3/2013 Nitzschia x 6/3/2013 Scenedesmus 533 x 6/3/2013 Pediastrum 800 x 6/3/2013 Cryptomonas 933 x 6/3/2013 Ankistrodesmus 3867 x 6/3/2013 Golenkinia 400 x 6/3/2013 Oocystis 1200 x 6/3/2013 Anacystis x

13 7/24/12 Intense Anabaena bloom Tom Frost Reservoir No Anatoxina or Saxitoxin!

14 Tom Frost Reservoir 7/16/13 Aphanizomenon 7/30/13 Aphanizomenon

15 Sagar Reservoir 7/16/13

16 Coontail 9/2/14 Plaster Reservoir

17 What Should I Do? Leave town! Ignore it Hey, it s not our drinking water Panic Close the park Put a notice on your website Call 9News

18 Wait a Minute We re Scientists!

19 Keep Calm and Carry On YOU NEED A PLAN Identify the resources you have in-house Identify other resources that are easy to get Identify authorities needed to implement action Keep it simple! Publish it!

20 Why Monitor for Microcystin? Why not? It s a very common cyanotoxin The analysis isn t that difficult or expensive But if you monitor, you must USE the data Are you prepared for the consequences?

21 Microcystin Monitoring Plan Algae identification using light microscope Look for the known producers of microcystin: Anabaena Anabaenopsis Microcystis Oscillatoria Nostoc If total concentration exceeds 50,000 cells/ml, test for microcystin

22 Microcystin Monitoring Plan WHO Guideline for Moderate Risk in Recreational Water is 100,000 cells/ml Routine algae samples are taken from the middle of the pond For microcystin samples, we sample from the shore Most accessible part of the pond Highest risk of public health impact (kids, dogs)

23 Microcystin Monitoring Plan Microcystin results greater than 20 µg/l are ed simultaneously to: Environmental Services Superintendent Parks Environmental Health (part of Broomfield s Health and Human Services Department) In the report, we advocate for either posting a public health warning, or adopting a wait and see approach

24 Microcystin Monitoring Plan Environmental Health Makes the decision to issue a public health warning Notifies the City Managers Office Makes the decision to cancel the public health warning Parks Puts up (and takes down) signs in the affected area Environmental Services (and Lab) Technical assistance as needed Respond to citizen concerns Follow-up monitoring

25 Microcystin Monitoring Plan Follow-up testing is twice per week in accessible areas Recommend de-posting when microcystin results are less than 20 µg/l for two consecutive weeks

26 Postings for Toxic Algae

27 Postings for Toxic Algae

28 Postings for Toxic Algae

29 Communication is the Key!

30 Summer 2012 The Trails Pond