Water Quality Monitoring of Province Lake
Effingham & Wakefield, New Hampshire, and Parsonsfield, Maine
2014 Report - Published Online on July 15, 2015
2014 was the 24th consecutive year of water quality monitoring conducted at Province Lake. The first 23 years of monitoring were conducted as part of the New Hampshire Volunteer Lake Assessment Program (VLAP). For 2014, the Province Lake Association (PLA) decided to switch to the University of New Hampshire (UNH) Lakes Lay Monitoring Program (LLMP). Making this change had multiple benefits, including a longer sampling season, lower costs, and monitoring for additional parameters. Especially useful is that UNH personnel travel to the lake for sampling and take the samples back to the lab with them; this eliminated the 3-hour-plus round-trip that someone (usually Steve Craig) had previously needed to make to the VLAP laboratory in Concord. The downside is that the 23-year continuous record of consistent analyses by VLAP has been broken. There is also no longer a New Hampshire State Report. The impact, as described by Sara Steiner, NH DES VLAP Coordinator, in an email to me on 1/15/2015 is:
"UNH LLMP sampling methods are slightly different than VLAP. This may cause a disruption in some deep spot historical trend analyses, or at the very least you would have to note that starting in 2014 collection methods changed. Chlorophyll-a and Secchi disk transparency methods are the same. The collection of total phosphorus is slightly different as UNH collects and analyzes total phosphorus from a column of water (the same column chlorophyll-a is analyzed from), while VLAP collected a discrete total phosphorus sample at a single depth."
Sampling was conducted more times last season than any other year since sampling began in 1991. The deep spot was sampled 6 times (May through October). The standard inlets and lake outlet were sampled 7 times (April through October), while several other places were sampled 1-2 times.
Water samples in 2014 were collected by Steve & Mary Craig and by UNH personnel. I obtained the data for analysis directly from Bob Craycraft of UNH Cooperative Extension by email on 1/20/2015. Although the data do not go directly to VLAP, he said "we will be sending the data to DES for upload onto their Environmental Monitoring Database (EMD) once we have finalized the compilation of data from all participating lakes." All data are therefore public information. In order to compare 2014 UNH results to prior years, only the June through September data were used in this report.
Many of the terms in this report include hyperlinks to related web sites. By clicking on most of the underlined terms, you can access additional information. If the same word is hyperlinked more than once, the different occurrences lead to different web sites. Clicking on most photos will get you a large photo with wider angle and higher resolution. The same copyright applies to these photos.
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Overall Summary
- Despite some localized problems with E. coli bacteria in 2013, reported on in great detail with its own supplementary report last year, the datasheets I received for 2014 showed No E. coli sampling in 2014. Even so, it makes sense to stay out of the stream that flows from the golf course and drains into Province Lake at the beach along Rt. 153 near Shore Acres Road in Maine. That stream is contaminated with E. coli from wildlife, nothing that the golf course has done wrong. Also, you should never swallow lake water.
- We had no reportable cyanobacteria blooms in 2014 after having had them 4 years in a row, starting in 2010. Some mild blooms (not
worthy of a warning) were observed in June 2014, so 2014 was potentially a 5th bloom year, but nothing significant developed. This is good news! As of
2012, Province Lake was listed as "Marginally Impaired" in the "Primary contact recreation" (swimming) use category because of "Cyanobacteria hepatotoxic
microcystins", as a result of the recent pattern of blooms. "Marginal" means "relatively slight"(1).
WARNING: Since 2013 had multiple cyanobacteria blooms of varying severity starting in June, it is advisable to have a look at the water each time you or your children plan to swim. We got lucky in 2014 and so far in 2015, but caution is still advisable. Since a cyanobacteria bloom is readily visible, if you don't see it, swimming is safe. Photo courtesy of the PLA, 7/11/2013. - Water transparency was the 3rd best of the 10 most recent summers.
- Phosphorus concentrations and acidity in the upper layers of the lake rose somewhat in 2014, compared to 2013, but were still fairly average. By contrast, in the lower layers of the lake, the average phosphorus concentrations were the 2nd highest and the average acidity was the highest recorded during the 15 years since those parameters started to be measured in the year 2000.
- [Same status as last year's report, since the DRAFT 2014, 305(b) Report / 303(d) List has not yet been issued. Listings are only issued every 2
years, so there is no 2013 update. As of this writing, Ken Edwardson of NH DES said "The 2014 draft has not yet been released.", then
"Before the summer is out I hope."]
Since 2010, Province Lake has been listed as "Marginally Impaired" in the "Aquatic life" use category for chlorophyll-a and total phosphorus. By 2008, the lake had already been so listed for pH and mercury in fish. On the 2012 list for "Drinking water after adequate treatment", Province Lake still received the best rating, "2-G", defined as "Supports parameter well above criteria". However, for swimming and boating uses, Province Lake has been downgraded from the "2-G" designation it had in the 2010 list. Province Lake is now considered "Marginally Impaired" for swimming, because of the repeated cyanobacteria blooms. For boating, Province Lake is now designated as the second highest quality, "2-M", defined as "Supports parameter marginally above criteria." The rating is not higher because the lake is now designated "2-M" for E. coli bacteria. Read what "impaired" means.
Details
This section provides a more detailed look at the UNH LLMP water quality data for Province Lake in 2014. Note that for all comparisons to results from earlier years, ONLY the data from the 4 months of June through September of 2014 are used. It is wonderful that data are now being collected during more months, so that after several years of doing so, any trends might possibly be seen. Ten full years of identically collected data are necessary to perform valid statistical analyses, as was done by VLAP. Once there are 10 years of 6-month (lake) or 7-month (inlet/outlet) data, statistics may be run on the datasets that extend for 6 or 7 months. However, for long-term statistical analyses that include the 1991-2013 data, only the subset of data from 2014 onward that were collected during the 4 months of June through September may be used. Data from the excluded months is outside of the peak growing season, so is not typical.
1. Chlorophyll-a concentrations are used to indicate the average amount of algae (2) in the lake. The UNH data spreadsheet I received provided two conflicting chlorophyll-a datasets for samples that were collected at the deep spot in the lake at the same time. According to a UNH Sampling Highlights page posted online, the dataset to use is the one called "DES Composite". Using the June through September data from that dataset indicates that the 2014 chlorophyll-a concentrations that averaged 4.73 micrograms per liter (ug/L) were the 4th highest ever, exceeded only by the high levels observed during the weed removal activities of 1996 and 1997, and their lingering effects in 1998. This would represent a 69% increase over the 2013 average and would place our concentration 3% above the average of all NH lakes. The UNH highlights page quotes only a 4.3 ug/L average, because it uses all 6 months of data, diluting the results with the lower May and October concentrations that result from there being less algae in the lake during the cooler seasons.
My expectation is that the other dataset provided in the UNH spreadsheet is the one that used the same sampling method as used with VLAP and is the correct one to use when comparing to prior years. It indicates that the 2014 chlorophyll-a concentrations that averaged 3.16 ug/L were the 5th lowest ever. This would represent only a 13% increase over the 2013 average and would place our concentration at only about 70% of the amount that New Hampshire lakes had, on average. A low level is good because dying algae forms the brown floating bottom masses that come to your shore when the wind blows hard in July and August. The algae masses settle loosely on the bottom when the lake is still and cloud the water when wind or boat wakes stir things up. This may be unsightly, but it is not harmful to anyone or their animals.
Given the uncertainties described, I can make no conclusion about the chlorophyll-a status of the lake for 2014. This report will be updated if any scientific clarifications are received.
2. Water transparency (a measure of how deep you can see into the water) was an average of 2.83 meters (9.3 feet), a slight increase of 3 inches from the prior year (2013). It is the 3rd best transparency of the 10 most recent summers. The transparency I am reporting is that which is measured without a viewscope. I use this one because it represents how most people actually observe the lake. The viewscope method represents how you would see the lake through a diving mask or swim goggles. For comparison, the 2014 viewscope transparency was 3.30 meters (10.8 feet).
As always, Province Lake's transparency was less than the statewide median (without a viewscope) of 3.2 meters (10.5 feet), but is not unreasonable considering that we have a shallow lake, so sediments are easily stirred up.
The deepest part of the lake is only 16 to 17 feet deep, as shown on the bathymetric chart.
3. Phosphorus is a nutrient required for growth of photosynthesizing organisms and is typically the nutrient whose availability most limits plant, algae, and cyanobacteria growth in NH lakes. In 2014, the average phosphorus levels in the upper water layer (sampled at 2.0 meters depth) increased 24% over the previous year, which itself had tied with the year 2000 for the lowest we had on record, after 3 consecutive year of decreases (2011-2013). The 2014 level once again exceeds that in 50% of the lakes in NH, as it usually has. The 2014 phosphorus level is the 4th highest of the 10 most recent summers and the 11th highest in 24 years, so it is about average for Province Lake.
Such concentrations over the years have been high enough to earn Province Lake a "Marginal Impairment" listing in the "Aquatic life" use category because of total phosphorus concentrations. 2010 was the first year ANY water bodies were listed for total phosphorus, as explained in in 2013's Issue #5 of the Province Lake Water Newsletter.
In the lower water layer (sampled at 4.0 meters depth), the average phosphorus levels were the 2nd highest since those measurements started in the year 2000. Only the 2001 concentration was higher. This represents a 60% increase from our very low reading of the previous year (2013), a disconcerting leap. Our lower layer phosphorus was above both the NH median and the median for lakes in NH that are similar to Province Lake, whereas it had been below both medians in 2013. It is important to educate lake users on the importance of operating jet skis and boats at slow speeds in shallow areas to minimize disturbance to sediments and vegetation. Churning up the bottom sediments releases phosphorus, which promotes plant, algae, and cyanobacteria growth; increases turbidity (scattering of light by suspended particles), and decreases clarity.
The phosphorus concentration at the Rt. 153 Inlet (in NH, near the state line) continues to be elevated, but its 2014 level was only 4% higher than the previous year and was still the 4th lowest since monitoring began in 1991. The average phosphorus concentrations measured at the Island Inlet on Bonnyman Road were a 14% increase over 2013, but were still the 3rd lowest seen since monitoring began in 1991. Only 2012 and 2013 were lower. Phosphorus clings to sediments, so soil erosion and sediment disturbance can increase phosphorus concentrations. Both inlet locations have a history of elevated and fluctuating total phosphorus concentration. The lake view at the Island Inlet is shown here. Click the photo to see where the sample is taken.
Since these two inlet streams are still near their 24-year lows, clearly they are not the cause of the 24% and 60% upper and lower water phosphorus concentrations in the deep spot of the lake. The Campground Stream continues to have the low phosphorus concentrations it always has, so it is also not the source. The available data do not reveal a cause.
4. We had never sampled Province Lake for nitrogen as part of VLAP, but it is now included in the new UNH Lakes Lay Monitoring Program. A 1987 DES Lake Assessment Program survey had concluded that plant and algae growth in Province Lake is actually limited by the amount of nitrogen, rather than by phosphorus. Now that nitrogen is being monitored, we have the potential to eventually learn if that is true. Meanwhile, it is important to be sure nitrogen-containing fertilizers are not used near the shoreline, or streams or ditches feeding the lake, and to be sure septic systems are operating properly. It would also be a tiny help not to pee in the lake while swimming; each time adds about 40 milligrams of nitrogen to the water.
5. Province Lake started Summer 2013 with a cyanobacteria bloom on June 21st and occasional sightings were reported throughout that summer. Fortunately, no sightings worthy of a Lake Warning occurred in 2014.
Province Lake experienced its first reported and confirmed cyanobacteria bloom since the 1970's in September 2010. Having had blooms 4 years in a row (2010-2013) means we are susceptible to having them in future years, especially in late summer, when at least 3 of the blooms occurred. When a cyanobacteria bloom is in progress (see description below), there is no way for us to know if it is toxic or not, so we need to act as if it is toxic. Therefore, it is important to know what a bloom looks like and act accordingly. If a cyanobacteria bloom is suspected, there may be Facebook postings and/or email alerts issued.
What a Cyanobacteria Bloom Looks Like: Large concentrations of cyanobacteria would be caused by a bloom, which would be seen as the formation of a green, blue, or pink surface scum in a section of the lake. Bear in mind that this is different from the tan or yellowish foam seen sometimes after strong winds. If present in large amounts, cyanobacteria can be toxic to animals and humans. While recreational exposure to cyanobacteria toxins is a major concern of NH DES, there have been no documented cases of cyanotoxin-related illnesses in New Hampshire. Photo by NH DES, courtesy of the PLA, 2012.
If you think you are seeing a cyanobacteria bloom, stay out of the water and especially, keep your children and pets out of the water. Call the NH DES Cyanobacteria Hotline at (603) 419-9229 to describe what you see. If suspicious, during "swim season" NH DES may sample and analyze the suspected bloom, then post a Lake Warning if there is any danger. They will monitor the situation and remove the postings when all is clear.
The best ways to avoid having cyanobacteria blooms are by eliminating fertilizer use on lawns, keeping the lake shore natural, protecting against shoreline erosion, and properly maintaining septic systems. The specific causes of our blooms is unknown, but preventing future blooms is a major goal of the Watershed Management Plan.
6. A pH between 6.5 to 7.0 is ideal for fish. pH is the measure of acidity, where 7.0 is neutral, below 7 is acidic, and above 7 is basic. Ours in 2014 was an average of 6.76 in the upper layers and 6.21 in the lower layers. This appears to be a significant drop from the 6.88 and 6.79 respective pH's measured the prior year. The upper layer is only the 11th most acidic in 24 years, but the lower layer is the most acidic it has been in the 15 years it has been measured. In the lower layer, the least acidic reading (6.51) in 2014 was actually more acidic than the most acidic reading (6.70) the prior year. The state average in the upper layers is 6.6.
Meanwhile, the pH at the lake outlet (7.01, ~ neutral) is one of the least acidic results on record. No particular cause for the sudden acidification of the lower lake layers is apparent in the data, but the neutral pH at the outlet at least indicates that there is probably no measurement bias towards acidity by the switch from VLAP to UNH monitoring.
A Note on my Analysis: VLAP measured lake pH by collecting discrete samples at 2.0 and 4.0 meter depths, then measuring them in the lab. UNH uses a direct reading instrument and takes measurements at 0.1 meter and 0.5 meter, then at 0.5 meter increments down to near bottom at 4.5 meters. In order to compare the UNH results to earlier years of data, I averaged the pH data at 1.5, 2.0, and 2.5 meters to represent the 2.0 meter depth. Likewise I averaged the pH data at 3.5, 4.0, and 4.5 meters to represent the 4.0 meter depth.
Exceedances of the Water Quality Criteria for pH are defined as: pH < 6.5 or pH > 8.0. The state average pH of 6.6 is barely better than the 6.5 criterion, therefore a large number of New Hampshire water bodies are listed as "Slight impairment - marginal condition" in the "Aquatic life" use category for pH. Questions 4 and 4A of the 2012 supplemental report explains why Province Lake is listed as "Slight impairment - marginal condition" for pH and will probably stay listed for years.
7. Province Lake was listed in 2008 as impaired for mercury in fish (3). Two fish from Province Lake tested in 2009 were shown to have safe mercury levels, but just two fish cannot be assumed to be sufficiently representative of all fish in the lake, especially since 6 years have passed since those fish were caught. It's better to be cautious and do catch-and-release, which makes for better fishing anyway, not to mention leaving food for the loons and bald eagles.
| Depth (meters) | DO (% saturation) |
|---|---|
| 0.1 | 94% |
| 0.5 | 95% |
| 1.0 | 95% |
| 1.5 | 95% |
| 2.0 | 94% |
| 2.5 | 92% |
| 3.0 | 91% |
| 3.5 | 81% |
| 4.0 | 77% |
| 4.5 | 75% |
8. Thanks to the new UNH program, dissolved oxygen (DO) was measured monthly 6 times (May - October), rather than once every 2 years under the latest VLAP schedule. The DO concentration measured in 2014 showed a high degree of saturation in the deep part of the lake. Averaging across all depths for all 6 months, the DO was at 89% saturation. The table displayed to the right provides the average saturation at each depth for the 6 months. This detail of DO data was never available under VLAP, so there really is no past data to compare it to in any statistically meaningful way, except to say that generally, DO levels in Province Lake have been satisfactory. A high oxygen level is a sign of the lake's overall good health. I encourage powered watercraft to operate far from the shore to mix the deep waters and boost the oxygen concentration, while minimizing their operation in the shallows.
9. Much E. coli bacteria testing (22 samples) was done in the previous year (2013) as part of the study for the Province Lake Watershed Management Plan. Of the 22 E. coli samples, 5 exceeded the strictest NH DES health advisory level for public beaches. You may read about the 2013 results in great detail in last year's supplementary report. Despite those very localized problems with E. coli bacteria in 2013, the datasheets I received for 2014 showed No E. coli sampling having been performed in 2014.
Even so, it only makes sense that everyone should still stay out of the stream that flows from the golf course and drains into Province Lake at the beach along Rt. 153 near Shore Acres Road in Maine, shown here. Click photo for wider angle. If it has been raining recently and you see that water is flowing into the lake at that location, it would be best to avoid swimming too close to it. There is no evidence that the golf course has done anything wrong. Wildlife are almost certainly the source of the E. coli measured in 2013, although that reason does not make the E. coli concentrations safe. Pass on this information to others. Those with private beaches near the Island Inlet should also be cautious. Generally, it is probably best to avoid swimming in any streams as they flow into the lake, since even those with E. coli levels considered safe had measurable amounts of bacteria in 2013. And it is always best to avoid swallowing lake water.
10. European water-starwort: Callitriche stagnalis, commonly known as either "pond water-starwort" or "European water-starwort", appeared in Province Lake during 2014. It is not native to Province Lake and is listed as "potentially or probably invasive" in Maine and some other states, although not yet in New Hampshire. Its dense weed bed is a threat to native plants that might otherwise grow in that spot, and is also an impediment to swimming in that area. There is an extensive detailed report about the appearance of C. stagnalis in Province Lake published on this web site.
Reminders of Bigger Environmental Issues for Province Lake and Its Environs
Loons and Lead
Most birds swallow small stones to help them digest food. Many fishing sinkers fall into the size range that loons prefer. Being fish-eaters, loons have a lower stomach pH than waterfowl that eat vegetation, such as geese and most ducks. The lower pH more effectively dissolves the lead, which then kills the bird. Poisoning from ingestion of lead objects has been identified as the #1 cause of loon deaths in fresh water. Therefore, most lead fishing sinkers have been outlawed so, if you still own any lead fishing gear, please stop using it immediately. For definitive and up to date information on this subject, please see the Loon Preservation Committee's Loons and Lead web page. This is a photo of the loon nesting raft on its day of installation in 2015, approached with the permission of Steve Craig.
Earthworms
If you bring up or buy earthworms to use as bait, you absolutely should not release them on the ground, since they are not native to New England and they can eat up the leaf litter and disturb the soil. This article in OnEarth magazine describes the situation very readably and thoroughly. Either use up your worms or give them to someone else who can use them. I had previously said you could dump them in the lake, as far from shore as you can, but both this article and a worm biologist I asked said that won't necessarily work, because earthworms can survive underwater and swim to shore. Some earthworms actually migrate to new territories by crawling into streams and taking a free ride downstream! Freezing for a few weeks or soaking in rubbing alcohol (isopropanol) probably work better. If you find euthanizing them in isopropanol to be too upsetting to watch, I have been told by the worm biologist that you can soak them in Epsom's salt solution first to relax them. Any soil you had the worms in can contain eggs or other life stages, so should be treated and not be dumped on the ground either. See the 2011 report for more details, including a video. The native plants, tree frogs, toads, salamanders, and other little creatures that live in the woods will thank you!
Polystyrene Foam in the Lake
Polystyrene foam is a convenient product to provide flotation for swim rafts and for other purposes. Unfortunately, when exposed to ultraviolet (UV) radiation from sunlight, it can start degrading within months. Mechanical action from wave impacts can help to break it up once it has been weakened by UV. Whatever the means of degradation, polystyrene foam used in the lake is destined to break up and cause long-lasting plastic pollution. The foam physically breaks up into smaller and smaller pieces, but never really goes away. One of these photos shows blue polystyrene foam flakes washed up on the Maine section of beach along Rt. 153. The other shows a pail's worth of blue polystyrene foam flakes that came floating by my place October 17, 2013, when I just happened to be in the lake in my waders. I walked around in the weeds and gathered it all up, along with some other litter. It clearly had been released from one place nearby and had not dispersed widely yet. To protect the lake, the water downstream, and ultimately the ocean, if you need flotation, it is better to use something that will not fall apart, such as plastic barrels or aluminum pontoons. If you are already using polystyrene foam, inspect it each year and dispose of it properly once it inevitably starts to degrade.
Asian Longhorned Beetle
Online
I started the Province Lake Water Newsletter in 2013 to cover various topics related to water quality, invasive species, or other issues that have some bearing on the region surrounding Province Lake. I encourage you to sign up for these occasional emails HERE. You will receive a brief email you must respond to to confirm your free subscription. This feature keeps other people from signing you up. Signing up gets you the emailed newsletter only and your information will not be shared with anyone. You can easily unsubscribe or resubscribe at any time.
Last year's water quality summary report is posted HERE. That is the 2013 report, published online July 16, 2014.
There are now 144 members of the Facebook group called "Province Lake, New Hampshire & Maine", which is not affiliated with the any organization, but where people interested in the lake and nearby areas can share information. Province Shores Campground and Jolly Roger Village also have Facebook groups primarily for members, and there has been outreach regarding water quality issues by that means. These Facebook groups have been used to post cyanobacteria warnings, official or otherwise.
THANK YOU NOTE: I want to thank Steve Craig for taking the lead on the VLAP water sampling activity since 2004. Thank you to Steve, and others who have helped out from time to time! Steve can always use more volunteers to help him with sampling, etc., so please contact Steve (at Weeds@ProvinceLake.org) or me (at province-lake-water@cox.net ) if you are interested in helping out. The PLA currently coordinates and provides financial support to the VLAP effort on Province Lake. You do not need to be a member of the PLA to volunteer, and have no obligation to join if you do volunteer, although new or returned members are always welcome.
Happy Summer,
Norm Dudziak, P.E., I.M.
See Province Lake statistics HERE.
Footnotes
- For sub-categories 4A-M and 5-M, "the impairment is relatively slight or marginal", according to page 10 of the "2012 Section 305(b) and 303(d),Consolidated Assessment and Listing Methodology", the CALM, document #NHDES-R-WD-12-2, dated January 2014.
- While some still mistakenly use the term "algae" to refer to cyanobacteria, in this report "algae" is only used to refer to true algae. Cyanobacteria are bacteria, not algae. Other than both being microscopic cells, they are fundamentally different. See Footnote #2 of 2013 Newsletter #5 for a detailed explanation.
- Note 3 of the "Final- 2008 List of All Impaired or Threatened Waters" stated "all surface waters in New Hampshire are also included on this list due to statewide fish/shellfish consumption advisories because of mercury levels in fish/shellfish tissue." This issue is further explained in Question 1 of the 2012 Supplemental Report.
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