DH Environmental Consulting

Chemical dosing of a lake using a helicopter (Photo: Bill Harding)

Most lake managers are aware of the importance of keeping in-lake phosphorus levels to the absolute minimum possible – and to ensure that this is managed at the source of the problem, not once the nutrient is already in the lake.  Once in the lake, nutrient attenuation (unless the lake is quite small and shallow) is generally very difficult.  Prevention is always better than ‘end of pipe’ cures – but this is a lesson that is not easily learnt  in the field of lake management! Read more »

Lots of good news to end this week – well, at least news about informed approaches.  All too often we read reports about attempts to manage pollution in lakes at the wrong end of the pipe, i.e. after the problem is already in the lake.  This has the same level of logic as a security guard, knowing there is good chance of being shot, not wearing a bullet-proof vest on the reasoning that “we can get the bullet out later”.  This short-sighted thinking has epitomized wastewater treatment for decades, with engineers saying “if the pollution gets worse we will simply treat the water we draw from it better”.  This has been a surprising and stupid concept on all sorts of levels, not least completely ignoring ecosystem damage.  Curiously, the wastewater engineering fraternity are very quiet on the topic of eutrophication, suggesting their heads are still firmly in the sand on this one.  In a recent limited poll of South African companies providing wastewater treatment engineering services to local authorities, not one identified effluent quality as a challenge to modern wastewater treatment! Read more »

Algal warning (Source: CBS)

Here’s a little video clip explaining the dangers of swimming in some Oklahomalakes while they have cyanobacteria in them.   A busy USA holiday weekend is upon us, and authorities report finding more dangerous Blue-Green Algae.   The U.S. Army Corps of Engineers says tests revealed algae that’s generally found several feet below the surface and hard to spot. They’ve closed off Lake Texoma to human contact. The algae are still present in Green Country lakes too.  Advisories also have been issued for portions of Skiatook, Eufaula, Keystone, Waurika, Tenkiller, and Fort Gibson lakes. Read more »

Thick algal scums should be avoided by humans and animals (Photo: Bill Harding)

As Grand Lakebounces, or perhaps, wobbles back to normality after the algal scare of the July 4th weekend, questions are being asked about the possible lack of balance, in favour of sensation, that accompanied the reporting that exploded the day or so before the weekend – and which kept people away?  A quote from today reads: “We do not suggest that you [the press] not report legitimate news stories. We only ask that you carefully evaluate the veracity, tone and quantity of the words you put on paper, and their potential negative impact on others. The pen is, indeed, mightier than the sword“.  Read more »

The 4th July weekend algal scare at Not So Grand Lake has dissipated, but the economic effects may be long lasting.  Members of the public may be loathe to return unless the lake managers do a thorough job of ensuring that they can show that the algal problem has been managed properly. Read more »

Praying mantis, Miomantis caffra Saussure (Photo: Bill Harding)

So far, cyanobacterial events in the northern hemisphere summer have been confined to the USA, and therein mainly to Oklahoma and Iowa.  95 out of 129 Oklahoma lakes sampled are impaired by eutrophication.  The presence of toxins in Lake Hudson have not yet been confirmed.  I wonder if they are aware of the Abraxis test kits that provide an answer at the lakeshore?   Toxic algae have, however, been confirmed in Lake Gibson.  In Iowa, there have been getting numerous reports of blue-green algae on Center Lake.  Some of that algae has been seen making its way through waterways that drain into Hayward’s Bay on West Lake Okoboji.

A farmer-led group wants the public to know its members are working to implement solutions for nutrient runoff into Grand Lake.

Photo: Bill Harding

Keystone Lake has benefitted from the problems at Oklahoma’s Grand Lake. Officials say the weekend is packed with visitors. They believe there’s more traffic because many are concerned about the [toxic algae] issue at Grand Lake.  The usually crowded waters of Grand Lake are close to deserted Saturday morning, July 2. Lake goers are heeding the warnings of Grand River Dam Authority and avoiding contact with the blue green algae infested waters (some good pictures at this link). Read more »

News reports today were 90% dominated by Grand Lake. Medical doctors agree the blue-green algae is something people need to take very seriously.  “With the warnings, stay out of the water. I know with the holiday season coming up everybody is going to be tempted to get in the water, get their boat in the water.” U.S. Sen. Jim Inhofe said Friday he is convinced he became ill after swimming in the algae in Grand Lake earlier this week.  One of the local dailies has listed a set of FAQs for cyanobacteria.  Oklahoma’s governor Mary Fallin says her family planned a trip to Grand Lake for this weekend and is still going. She says there’s a lot to do around Grand Lake even if the water is off-limits. Read more »

Press reports are dominated today by the possible closure of Grand Lake for the Fourth of July weekend.  Emergency meetings have been scheduled.  The Department of Environmental Quality says tests on Wednesday found blue green algae at Party Cove and Ketchum Cove, two popular areas of the lake.  Excessive heat warnings for the region indicate that the algae are getting all the solar energy that they need.  Kansas Department of Health and Environment officials have issued Blue-Green Algae advisories or warnings for several Kansas lakes. An advisory allows for boating and fishing, but all other contact with water is discouraged for people and pets. A warning indicates concentrations of algae above the recommended level for recreational water use. Advisories are currently in effect for Marion Reservoir and Old Herington City Lake in Marion County. Lakes currently under warning are Memorial Park Lake in Barton County, Meade State Lake in Meade County and Logan City Lake in Norton County.  Read more »

OK, lets get June up to date while its still June!

Lets start in Nova Scotia where algal scum has been noticed creeping across the top of Yarmouth County’s Lake Vaughan. Other Yarmouth County lakes including Ogden and Fanning are also reported to be in bloom.  Geographically close-by in Washington, the latest samples from Anderson Lake contain more than 1,000 times the safe level of a potent neurotoxin, the highest level of the algae-created poison seen at the popular fishing hole since it set a deadly world record in 2008.  Test results received Friday showed 1,112 micrograms per liter of anatoxin-a, for which the safe level is 1 microgram per liter. “It’s the most since 2008,” said Greg Thomason, Jefferson County environmental health specialist. In 2008, Anderson Lake water contained 172,640 micrograms per liter of anatoxin-a!  Green Lake (also in Washington) has three types of cyanobacteria present and toxins. Read more »