Killing Hour - Lisa Gardner [117]
“Well,” he said shortly, “we can test a water sample for all sorts of things: pH, dissolved oxygen, temperature, turbidity, salinity, nitrogen, ammonia, arsenic, bacteria . . . Then there’s water hardness, tests for various inorganic constituents such as iron, manganese, and sulfates, as well as tests for various water pollutants. So testing, yeah, we can do that.”
“Good, good,” Mac said encouragingly.
“Just one hitch, though.” Knowles spread his hands in a helpless gesture. “We’re not out in the field, and you can’t do squat with six drops of water.”
Mac raised a startled brow. He glanced at Kimberly, who shrugged. “At least we brought you water,” she commented. “We only gave Ray a picture of a leaf.”
“Damn right. And I did good,” Ray boasted. “So don’t you ruin our track record now, Knowles. We keep this up, and maybe we can get our own TV show. You know, Law and Order: U.S. Geological Survey Unit. Think of the chicks, Brian. Think of the chicks.”
Knowles, however, didn’t appear convinced. He leaned back in his desk chair and locked his hands behind his head. “Look, I’m just being practical here. To get accurate results from any sort of water test, you need to be at the source, looking at the sample in situ. The minute you bottled up this water, a couple of things happened. One, you changed the temperature. Two, you removed it from its oxygen source, rendering a test for diffused oxygen useless. Three, the pH is going up from off-gas. Four, you may have contaminated the sample from the container itself, and five . . . Well, hell, I can’t think of five at the moment, but let’s just agree it’s not good. Whatever I do to this sucker, the results are about as meaningful as a sixth toe—gives you something to look at, but doesn’t do a damn thing.”
“But we don’t have a source,” Mac reminded him curtly. “That’s the whole damn point. This sample is what we’ve been given, the source is what we gotta find. Come on, surely there’s something you can do.”
Mac stared at the man with mute appeal. After another moment, Knowles caved with a sigh. “It won’t be accurate,” he warned.
“At this point, we’ll take an educated guess.”
“I don’t know if I’d even call it that.” But Knowles was fingering the glass tube bearing their precious sample. “You’re sure you don’t have more? I’d prefer about forty milliliters.”
“The best I could do would be six more drops.”
Knowles blinked. “Damn, whoever gave you this was definitely feeling stingy.”
“He likes a challenge.”
“No kidding. I don’t suppose you’re gonna tell me anything more about this case.”
“Nope.”
“Ah well, never hurts to ask.” Knowles sighed again, sat up in his chair and stared intently at the sample. “Okay. It’s possible to test for salinity. We just need enough water to cover the end of the probe. I could do pH, which also uses a meter. Of course, the probe on the pH meter can deposit a tiny amount of potassium chloride in a sample, raising the electrical conductivity and screwing the salinity test . . . So we do salinity first, I guess, then examine pH. As for mineral testing . . . Hell, I don’t know if any of our test equipment is even calibrated for a sample this small. Bacteria tests . . . You have to run the water through a sieve, not sure that would do much here. Same with testing for plant matter.” He looked up. “Salinity and pH it is then, though I’m telling you now, the sample size is too limited, the methodology flawed, and all the results will be too relative to draw any sort of accurate conclusions. Other than that, what the hell, I’m game. I’ve never worked a murder case before.”
“Any information is helpful,” Mac said grimly.
Knowles opened a drawer. He pulled out a small plastic box with a well-worn label that read Field Kit. He popped open the container and started pulling out handheld meters complete with long metal probes. “Salinity first,” he murmured to himself, fiddled around, then stuck the probe in the water.
He didn’t say anything right away. Just grunted a few times.
“What does a